CIC Practice Test 1

Important considerations regarding blood culture specimens include: 1) Collect prior to the initiation of antimicrobial therapy 2) Collect from a central venous catheter whenever possible 3) Ensure that the volume of the specimen collected is sufficient 4) Culture of specific sites is not recommended for surveillance a. 1, 3 b. 2, 4 c. 1, 4 d. 3, 4

A. 1, 3 The accuracy of a blood culture can be impacted by a wide variety of factors, many of which pertain to skin antisepsis and/or specimen collection techniques. The venipuncture site should be cleaned with an antiseptic first to minimize the risk of contaminating the blood specimen with common commensals. It is critical that blood cultures be drawn prior to initiation of antibiotic therapy. Blood may not be sterile immediately following antimicrobial therapy. If empiric antibiotic therapy is initiated on an emergency basis, cultures should be obtained as soon as possible following the first dose. The volume of blood obtained for culture is a critical variable in detecting bacteremia or fungemia. Specimen collection from a central venous catheter is not recommended due to the risk of intraluminal bacterial contamination of the device. Percutaneous venipuncture from two separate sites is preferred.

Which of the following recommendations related to disinfection and sterilization in healthcare facilities is a CDC category 1A recommendation? 1) "Before use on each patient, sterilize critical medical and surgical devices and instruments that enter normally sterile tissue or the vascular system or through which a sterile body fluid flows" 2) "Meticulously clean patient-care items with water and detergent, or with water and enzymatic cleaners before high-level disinfection or sterilization procedures" 3) "In hospitals, perform most cleaning, disinfection, and sterilization of patient-care devices in a central processing department in order to more easily control quality" 4) "Perform low-level disinfection for noncritical patient-care surfaces (e.g., bedrails, over-the-bed table) and equipment (e.g., blood pressure cuff) that touch intact skin" a. 1 b. 1, 3 c. 1, 2, 4 d. 1, 2, 3, 4

A. 1 The CDC has established a system for cataloging recommendations based on the amount of data available to support the recommendation. Category 1A recommendations are strongly supported by epidemiologic, clinical data, or experimental data from well-designed studies. Sterilization of medical instruments that will come into contact with sterile tissue or the vascular system is a Category 1A recommendation.

What is the probability of committing a Type I error if the p value is 0.10? a. 1 in 10 b. 1 in 100 c. 1 in 5 d. 1 in 20

A. 1 in 10 A Type I error occurs when one rejects the null hypothesis (H0) when it is true. This is also called a false-positive result (we incorrectly conclude that the research hypothesis is true when in fact it is not). The p value or calculated probability is the estimated probability of rejecting the null hypothesis of a study question when that hypothesis is true. A p value of 0.10 indicates a 10 percent (or 1 in 10) chance of making a Type 1 error.

Which of the following organisms have been associated with NOTES the transmission of infections after body piercing? 1) Atypical Mycobacterium species 2) Staphylococcus species 3) Pseudomonas species 4) Haemophilus species

A. 1, 2, 3 Body piercing activities can transmit infectious diseases. Bacterial infections may result from improper initial piercing technique or from poor hygiene. The organisms involved in most earlobe-piercing infections are often considered normal skin flora, including Staphylococcus and Streptococcus species. Higher ear piercings in the ear cartilage have been associated with more pathogenic organisms, including Pseudomonas species. Multiple cases of atypical Mycobacterium infections after piercing have been reported.

Program evaluation is necessary to measure change and growth in the learner. The following program elements should be evaluated in order to demonstrate efficacy and impact. 1) Appropriateness of the program design 2) Adequacy of the teaching and instructional resources 3) Knowledge, skills, and attitudes learned by the participants 4) Assessing the educational needs of the attendees a. 1, 2, 3 b. 1, 3, 4 c. 2, 3, 4 d. 1, 2, 4

A. 1, 2, 3 Program evaluation is a systematic method for collecting, analyzing, and using information to assess the effectiveness and efficiency of the educational offering. Specific program elements that must be evaluated include appropriateness of program design, adequacy of teaching and instructional resources, and the knowledge, skills, and attitudes learned by the participants. Needs assessments identify deficiencies in knowledge, skills, or attitude and should be conducted prior to the development of the program.

A patient who underwent intraocular surgery was diagnosed with a noninfectious endopthalmitis after the procedure. The IP initiates an investigation to identify the possible cause. Which of the following factors should be considered? 1) Improper handling, cleaning, and rinsing of the instruments 2) Improper labeling of the solutions 3) Gloves and powder 4) Prophylactic antibiotics administered 2 hours before the procedure a. 1, 3 b. 1, 2 c. 3, 4 d. 2, 4

A. 1, 3 Endophthalmitis is an inflammatory condition of the intraocular cavities (aqueous and/or vitreous humor) usually caused by infection. Noninfectious (sterile) endophthalmitis may result from various causes such as retained native lens material after an operation or from toxic agents. Improper cleaning and rinsing of surgical instruments can leave a residue, which can irritate the eye and cause an inflammation. Gloves, especially those with powder, can also cause inflammation of the eye during surgery.

Improved hydrogen peroxide contains: a. Anionic and/or nonionic surfactants b. Glutaraldehyde c. Peracetic acid d. Chlorine

A. Anionic and/or nonionic surfactants Improved hydrogen peroxide contains very low levels of anionic and/or nonionic surfactant in an acidic product that act with hydrogen peroxide to produce microbial activity. This combination of ingredients speeds the antimicrobial activity of hydrogen peroxide and clean efficiency.

Nursing Administration has announced the opening of a simulation lab at an acute care facility. The IP has been asked to develop a simulation setting dedicated to teaching infection prevention best practices. Which of the following is as example of a simulation activity? a. Creating an isolation room to practice use of Isolation Precautions b. Modeling proper hand hygiene techniques and having participants model back c. Showing an interactive video of cleaning procedures and asking participants to identify correct and incorrect elements d. Setting up a display of education materials concerning influenza vaccinations

A. Creating an isolation room to practice use of Isolation Precautions The goal of simulation is to create a controlled learning environment that closely resembles the practice setting. This process facilitates use of practical and critical thinking skills on the part of the participant and serves to protect the safety of the patient. One example of a simulation room may be to create a mock isolation room. The goal may be to increase the awareness of the nursing staff regarding common infection prevention infractions that may occur during the provision of care. The simulation would enable participants to practice infection prevention activities necessary to care for patients.

Which of the following air filtration methods has the highest filtering efficiency compared to the others? a. Diffusion b. Straining c. Impingement d. Interception

A. Diffusion When air enters a facility's ventilation system from the outside it passes through a series of filters that remove particulate matter. The first bank of filters has low to medium efficiency for removing particles and can include straining, impingement, and interception filtration methods. This air is then mixed with the recirculated air from the facility and filtered again with high efficiency filtration methods including diffusion filtration.

An infant in the Neonatal ICU (NICU) has been diagnosed with Malassezia furfur fungemia. What is the most likely source of the infection? a. Intravenous lipid infusions b. A healthcare worker's false fingernails c. Commercial powdered infant formula d. Respiratory transmission from a colonized family member or healthcare worker

A. Intravenous lipid infusions M. furfur is fungemia that is most often associated with lipid infusions.

A patient is admitted for a skin infection after swimming in the ocean. Which of the following organisms is the most likely cause? a. Mycobacterium marinum b. Mycobacterium avium c. Mycobacterium leprae d. Mycobacterium tuberculosis

A. Mycobacterium marinum M. marinum causes cutaneous lesions after exposure to swimming pools, fish tanks, or other water sources. The organisms may enter through previously unappreciated superficial nicks and abrasions. The lesions first appear as papules that later ulcerate. Because special culture conditions must be used to isolate the organism, the Microbiology Lab should be alerted if this is a diagnostic consideration.

A patient has been admitted with a wound infection. The lab reports that the stain of the wound culture is positive for AFB and the culture is positive for Mycobacterium marinum. Which of the following is the correct follow-up of this lab report? a. No further follow-up is needed b. Place the patient on airborne isolation c. Contact the local health department to report the Mycobacterium infection d. Place the patient on Contact Precautions

A. No further follow up is needed M. marinum is a bacterium found in water and may be the cause of wound infections. Infection with M. marinum is not transmissible, and infection with non-tuberculosis mycobacteria is not notifiable. No further infection control follow-up is needed.

A pediatric patient has been diagnosed with pediculosis. What is the most appropriate follow-up to prevent it from spreading to other patients or healthcare professionals? a. Place the patient on Contact Precautions until 24 hours after appropriate treatment has been initiated b. Require all visitors and HCP who enter the room to wear a disposable scrub cap for any patient contact c. Use an insecticidal spray in the room after the patent is discharged d. Prophylactically treat all family members and anyone with close physical contact with the patient

A. Place the patient on Contact Precautions until 24 hours after appropriate treatment has been initiated In addition to placing the patient on Contact Precautions, patient bedding, clothing, and waterproof personal items should be washed at high temperature.

Which of the following patient care units would be the best choice for conducting surveillance on wound infections with drug- resistant Gram-negative rod bacteria to prevent outbreaks? a. The Burn Unit b. The Orthopedic Medical/Surgical Unit c. The CICU d. The General Medical/Surgical Unit

A. The burn unit Infection is the leading cause of morbidity and mortality in burn patients, despite improvements in care. Burns increase a patient's susceptibility to infection by damaging both the patient's physical and immunological defenses. Skin is the largest organ of the body, and constitutes the first defense against infection. When burned, the integrity of the skin barrier is broken and normally sterile sites become vulnerable to microbes. Recent studies have shown an increasing prevalence of Acinetobacter, Klebsiella, and other Gram-negative rods in burn wounds. Although all of these above patient populations might be susceptible to Gram-negative rod wound infections, burn patients have the highest risk of Gram-negative wound infections, and therefore this unit is most susceptible to outbreaks with those organisms.

If chance is a likely explanation for the difference between a sample statistic and the corresponding null hypothesis population value, then: a. The difference is not statistically significant b. The sample results are not compatible with the null hypothesis c. The difference is statistically significant d. The null hypothesis can be rejected

A. The difference is not statistically significant A common use of statistics is hypothesis testing. A hypothesis is a statement of expected results. Hypothesis testing uses the distribution of a known area in the normal curve and estimates the likelihood (probability) that a result did not occur by chance. Significance levels show how likely a result is due to chance. In statistics, if a result is significant, it means that it is not due to chance. If chance is a likely explanation for the difference between a sample statistic and the corresponding null hypothesis population value, then the difference is not statistically significant.

An IP subscribes to several peer-reviewed journals. As she reviews published articles describing research findings, what question should she ask before incorporating the conclusions/findings of the article into the infection prevention program: a. Was the appropriate study design used and are the conclusions reasonable? b. Is the author well known and well published? c. Does the article state how to contact the author(s) with questions? d. Are the findings described in tables or graphs and easily understandable?

A. Was the appropriate study design used and are the conclusions reasonable? Many study designs, observational or experimental, are available to investigators. Understanding the advantages and disadvantages of each study design should prepare the IP to critically evaluate published research studies so as to appropriately assign value to the findings.

The Director of Infection Prevention and Control is developing an educational program to provide annual bloodborne pathogen training to healthcare personnel in her facility. There are approximately 7,500 employees who need annual training, and her team of fi e IPs has to provide and document this training while still carrying out all other department duties. What is the best method of delivery for this training? a. Web-based training sessions b. Educational cart c. Group lecture sessions d. Role play training sessions

A. Web based Although each of the delivery methods listed has benefits, the best method in this case is web-based training. It is easy to deliver to a large number of people, flexible so that people with varied schedules can complete the training at a time that is convenient for them, and easy to track by having employees register for training through an online system. Assessments can be built into web-based training so that learners can evaluate their understanding of the training while it is in progress and demonstrate their mastery of the material at the end of the training session.

An employee is exposed to blood and body fluids from a patient whose baseline testing revealed positive results in a rapid HIV test. The most appropriate follow-up test for the patient would be: a. Western Blot b. Viral Load c. HIV polymerase chain reaction d. CD4

A. Western Blot Rapid HIV tests can offer a result in 15 minutes. A negative rapid test is reported as a definitive negative HIV test. A reactive test result needs to be confirmed with standard serologic tests. The most commonly used laboratory test for diagnosis of HIV infection is the serologic detection of antibodies to the virus. The standard serologic test consists of a screening enzyme immunoabsorbent assay (EIA) followed by a confirmatory Western blot (WB). In a patient with a positive EIA test, the test should be repeated. In a patient with a repeatedly positive EIA test, a confirmatory WB is performed. These serologic assays show sensitivity and specificity rates of 99.9 percent

The IP is reviewing the facility's performance measures, which are used to benchmark against national data. The IP ensures that each performance measure includes which of the following characteristics: 1) Measure is reliable 2) Measure targets improvement in a health population 3) Measure is defined according to physician preference 4) Measure can be easily interpreted by the users of the data a. 1, 2, 3 b. 1, 2, 4 c. 2, 3, 4 d. 1, 3, 4

B. 1, 2, 4 Performance measures focus on outcomes or processes. They are used for internal improvement purposes, intra- or interorganizational comparisons, and by various external entities for making decisions about care. Performance measure should be designed to address improvement that is likely to have a significant impact to the health of a specified population. The measure should consistently track the events within an organization or across organizations and over time. The resulting data should be easily understood by the end-users (e.g., staff, facility leaders).

An IP collected the following data from the ICU for the month of March. How would she calculate the CAUTI rate the month of March? March 2014, 6 CAUTIs, 240 patient days, 180 catheter days a. (6 ÷ 240) × 1,000 = 25 per 1,000 patient days b. (6 ÷ 180) × 1,000 = 33.3 per 1,000 catheter days c. (180 ÷ 240) × 1,000 = 750 per 1,000 patient days d. (240 ÷ 180) × 1,000 = 1333.3 per 1,000 catheter days

B. A rate is calculated by dividing the numerator (number of occurrences) by the denominator (number of opportunities for that occurrence) and then multiplying by a constant. Basic formula for all types of rates: Rate = x/y × k Where: x = The numerator, which equals the number of times the event (e.g., infections) has occurred during a specified time interval. y = The denominator, which equals a population (e.g., number of patients at risk) from which those experiencing the event were derived during the same time interval. k = A constant used to transform the result of division into a uniform quantity so that it can be compared with other, similar quantities. A whole number (fractions are inconvenient) such as 100, 1,000, 10,000, or 100,000 is usually used (selection of k is usually made so that the smallest rate calculated has at least one digit to the left of the decimal point) or is determined by accepted practice (the magnitude of numerator compared with denominator). There are three important aspects of the formula: 1. Persons in the denominator must reflect the same population from which the numerator was taken. 2. Counts in the numerator and denominator should cover the same time period. 3. At least in theory, the persons in the denominator should have been at risk of the event or occurrence.

Examples of efforts to improve patient safety in the healthcare setting include: 1) Encouraging patients to ask their healthcare providers if they have washed their hands 2) Medication safety programs that report medication errors and inform staff of efforts to prevent repeated errors 3) Encouraging patients to ask questions about their treatments and medications 4) Emphasizing punitive reactions to mistakes a. 1, 2, 4 b. 1, 2, 3 c. 2, 3, 4 d. 1, 3, 4

B. 1, 2, 3 In healthcare organizations, surveillance, reporting, and analysis are the foundation of risk prevention programs, but targeted interventions must be deployed if patient safety programs are to be successful in reducing harm from medical errors and other adverse events. The Agency for Healthcare Research and Quality recommends that all healthcare organizations focus on the following infection prevention initiatives: 1. Improving hand hygiene 2. Utilizing barrier precautions to prevent transmission of infection 3. Prudent antibiotic use to reduce C. difficile and VRE 4. Preventing urinary tract infections 5. Preventing central venous catheter-related bloodstream infections 6. Preventing VAP 7. Preventing SSIs Medication errors are also common in healthcare and are addressed in TJC's list of sentinel events: "Any patient death, paralysis, coma, or other major permanent loss of function associated with a medication error." A culture of safety must prevent punitive reactions to mistakes, and staff members must feel confident that if they speak out about risk, their leaders will respond. Providers involved in medical errors must know that leaders will look beyond the obvious and drill down until the root causes of accidents and errors are found and that they will routinely evaluate systems and processes during any accident investigation.

Inadequate refrigeration of food may permit the growth of potentially harmful microbes. Interventions to prevent the growth of pathogens due to inadequate refrigeration include: 1) Train personnel to recognize and implement safe maintenance of refrigerators 2) Establish a method to record temperature on a regular basis 3) Make daily rounds to ensure that the freezer and refrigerator are clean 4) Schedule and perform regular preventive maintenance of freezer and refrigerator a. 1, 2, 3 b. 1, 2, 4 c. 2, 3, 4 d. 1, 3, 4

B. 1, 2, 4 Interventions to prevent the growth of microbes include: • When selecting/purchasing equipment for cooling or freezing, compare features that best meet the intended use, including operating range (e.g., an automatic defrost cycle can damage temperature-sensitive items), size, location of use, cleanable surfaces, durability, and maintenance needs. • Provide accurate temperature monitoring for refrigerators and freezers; an alarm system may be required (e.g., blood bank refrigerator) or desired. • Establish a method to record temperature on a regular basis (e.g., visualize and document daily or observe an automated recording chart each shift); include action to take if reading is not in the acceptable range. • Schedule routine monitoring of refrigerator and freezer alarms where applicable. • Test accuracy of thermometers; calibration may be required (e.g., blood bank, tissue freezer) by using standard regulations and/or recommendations. • Schedule and perform regular preventive maintenance of all freezers and refrigerators; include air vents, gaskets, cooling coils, and fans. • Walk-in refrigeration units may experience a condensation point if the building dehumidification is inadequate, resulting in mold proliferation. • Provide training for personnel in recognizing and implementing safe maintenance of refrigerators to include appropriate cleaning methods.

Strategies to prevent infection of a dialysis access site include the following: 1) Utilize an arteriovenous (AV) graft if a fistula cannot be established 2) Use a tunneled cuffed catheter for acute dialysis if use will be more than 3 weeks 3) Subclavian access is preferred over jugular options 4) Use femoral catheters only in bedbound patients for no more than 5 days a. 1, 3, 4 b. 1, 2, 4 c. 2, 3, 4 d. 1, 2, 3

B. 1, 2, 4 The risk of infection related to vascular access for hemodialysis varies with the type of vascular access used. Risk for bacteremia increases sevenfold in patients with a dialysis catheter compared to those with a primary arteriovenous (AV) fistula. It is recommended that an AV fistula be created and used for long-term hemodialysis treatment because of the lower incidence of infection. If an AV fistula cannot be established, an AV graft is the next preferred type of access. Because of infection risk, creation of the fistula in the upper arm is preferred over the thigh. For acute hemodialysis, where access for less than 3 weeks' duration is anticipated, vascular access may be obtained using a noncuffed or cuffed catheter. However, if a catheter must be used for access for longer than 3 weeks, a tunneled, cuffed venous catheter should be used. The preferred insertion site is the right internal jugular. Because there is a greater incidence of central venous thrombosis and stenosis when the subclavian is used, subclavian access should be used only when jugular options are not available and permanent vascular access is not required. In addition, tunneled cuffed catheters should not be placed on the same side as a maturing AV access if possible. Femoral catheters should be placed only in bedbound patients only with good exit site care and should be left in place for no more than 5 days because of associated infection rates.

A case of healthcare-associated Mycobacterium chelonae respiratory infection has been identified in a patient. Of the following exposures that the patient had in the facility, which should be investigated as a potential source of the infection? 1) Bronchoscopes 2) Dialysis 3) Hydrotherapy pool 4) Ice from tap water used during surgery a. 1 b. 1, 3 c. 1, 3, 4 d. 1, 2, 3, 4

B. 1, 3 Mycobacterium chelonae belongs to the family of nontuberculous mycobacteria (NTM) classified in the rapidly growing mycobacteria (RGM), Runyon group IV. M chelonae are ubiquitous in the environment and have been isolated from both natural and potable freshwater sources, soil, contaminated solutions, and reptiles. The organism can grow in distilled and unsupplemented water. Likely sources of healthcare-related exposure may occur from bronchoscopes that were processed with tap water or from exposure to a hydrotherapy pool.

Important elements of surveillance programs include: 1) Tracking diseases associated with the healthcare environment 2) Environmental sampling 3) Reviewing microbiology reports for antibiotic resistant organisms 4) Tracking and reporting HAIs as mandated by state/local public health requirements a. 1, 2, 4 b. 1, 3, 4 c. 1, 2, 3 d. 2, 3, 4

B. 1, 3, 4 Surveillance has been defined as the "ongoing collection, collation, and analysis of data and the ongoing dissemination of information to those who need to know so that action can be taken." It is an essential component of an effective infection prevention program. Surveillance programs should measure outcomes of healthcare, processes of healthcare, and selected events of importance to the organization. Routine or random, undirected microbiological culturing of air, water, and environmental surfaces in healthcare facilities is not recommended.

All of the 72 patients in a chronic hemodialysis center were tested for Hepatitis C virus (HCV). Eight of the patients were identified as HCV positive. During the following year, two of the dialysis center's patients who previously tested negative for HCV converted to HCV positive. What was the incidence for that year? a. 2.8 percent b. 3.1 percent c. 13.8 percent d. 7.2 percent

B. 3.1 percent An incidence rate is a measure of the frequency with which an event occurs in a population over a specified period of time. Incidence indicates the risk of disease in a population over a period of time. The incidence rate equals the number of new cases of a disease for a specified time period divided by the population at risk for the same time period multiplied by a constant (k). k = A constant used to transform the result of division into a uniform quantity so that it can be compared with other, similar quantities. A whole number (fractions are inconvenient) such as 100, 1,000, 10,000, or 100,000 is usually used (selection of k is usually made so that the smallest rate calculated has at least one digit to the left of the decimal point) or is determined by accepted practice (the magnitude of numerator compared with denominator). The numerator for this scenario is 2—the number of new cases. The denominator would be the number of patients who are at risk for developing HCV, which would be 64. Patients already diagnosed with HCV would not be included. Incidence rate in this scenario: 2 ÷ 64 × 100 = 3.125 percent

On September 1, there were 30 surgical patients in the hospital. Two of these were postop patients with SSIs. A total of 75 surgeries were performed in September. Six additional SSIs occurred in patients who had surgery in September. What was the numerator for an incidence rate in September? a. 30 b. 6 c. 8 d. 75

B. 6 An incidence rate is a measure of the frequency with which an event occurs in a population over a specified period of time. Incidence indicates the risk of disease in a population over a period of time. The numerator is the number of new cases of a disease during a specific time period. The denominator is the population at risk for the same time period. The incidence rate is equal to the numerator divided by the denominator and multiplied by a constant. Because there were six new cases after September 1, the numerator to calculate the incidence rate in this scenario is 6.

Which of the following Transmission-based Precautions category requires a negative airflow room? a. Contact Precautions b. Airborne Precautions c. Droplet Precautions d. Standard Precautions

B. Airborne Precautions Airborne Precautions are used to prevent transmission of infectious organisms that remain suspended in the air and travel great distances. These diseases include measles, smallpox, chickenpox, pulmonary tuberculosis, avian influenza and possibly severe acute respiratory syndrome-associated coronavirus. Patients should be placed in an airborne infection isolation (AII) room with negative air pressure relative to the corridor and at least 6 to 12 air exchanges with direct exhaust of air to the outside. Monitor the air pressure daily. Keep the door shut.

As a time-saving measure, hospital administrators in your facility have suggested that endocavitary probes do not need to undergo high-level disinfection because they are used with probe covers. How would you respond to this suggestion? a. Agree, because the probe cover prevents contact with mucous membranes and non-intact skin b. Disagree, because the probe covers are not 100 percent reliable c. Agree, because even without covers the probes don't contact mucous membranes and non-intact skin during use d. Disagree, because switching from high-level disinfection to low-level disinfection will not save time

B. Disagree, because the probe covers are not 100 percent reliable Any patient care items that come into contact with mucous membranes and non-intact skin must undergo high-level disinfection. While probe covers are used for endocavitary probes like vaginal probes, the probe covers are prone to perforation before and during use, which can lead to contamination of the probe during the procedure.

Hepatitis A is diagnosed by the presence of: a. Immunoglobulin G (IgG) for anti-Hepatitis D virus (HDV) b. Hepatitis A virus (HAV) Immunoglobulin M (IgM) c. Increase in anti-Hepatitis B virus (HBV)-related to previous Hepatitis B infection d. HAV IgG

B. Hepatitis A virus (HAV) immunoglobulin M (IgM) The clinical case definition for acute viral hepatitis is (1) discrete onset of symptoms (e.g., nausea, anorexia, fever, malaise, or abdominal pain) and (2) jaundice or elevated serum aminotransferase levels. Because the clinical characteristics are the same for all types of acute viral hepatitis, Hepatitis A diagnosis must be confirmed by a positive serologic test for IgM antibody to HAV, or the case must meet the clinical case definition and occur in a person who has an epidemiologic link with a person who has laboratoryconfirmed Hepatitis A (i.e., household or sexual contact with an infected person during the 15 to 50 days before the onset of symptoms). IgM is the first antibody built during immune response and is indicative of current disease

An employee has experienced an accidental needlestick injury while providing care to a patient. All of the following lab tests would be appropriate for the source patient except: a. Human immunodeficiency virus (HIV) b. Hepatitis B antibody c. Hepatitis B surface antigen d. Hepatitis C Antibody (Anti-HCV)

B. Hepatitis B antibody positive Hepatitis B antibody indicates past infection or immunity via vaccination. It does not indicate active infection. (See Table PE1-1)

Which of the following must be reprocessed by high-level disinfection? a. Non-critical items b. Semi-critical items c. Critical items d. Non patient-care items

B. Semi-critical items High-level disinfection must be used for processing of semi-critical items. These are items that will come into contact with non-intact skin or mucous membranes. High-level disinfection will inactivate all vegetative organisms but some spores may remain. High-level disinfection can be carried out by Pasteurization or by immersion in high-level disinfectants.

The biological indicator that was included in a steam sterilization load of non-implantable instruments has shown a positive result, as have biological indicators used in two additional follow-up tests of the sterilizer. The chemical indictor in the original load was reactive, as were the chemical indicators used in the followup tests. The log of all the runs indicates that the run conditions (temperature and time) were appropriate for the instrument load and there were no abnormalities in steam supply or electrical supply. Which of the following should be done next: a. The load should be released for use in the facility b. The sterilizer should be tested again with paired biological indicators from two different manufacturers c. The items from the load should be immediately recalled and reprocessed d. All items that were processed in that sterilizer since the time of the last negative biological indicator should be recalled and reprocessed

B. T he sterilizer should be tested again with paired biological indicators from two different manufacturers Biological indictors included in steam sterilization loads may show a positive result if the sterilization parameters are not met; if there is contamination of the growth medium in the indicator; or if the indicator was not manufactured properly. With steam sterilization, the instrument load does not need to be recalled for a single positive biological indicator test, with the exception of implantable objects. The log should be checked to ensure that the sterilizer was used correctly and maintenance should be contacted to determine if there was an interruption to steam or electrical supply. If there is no indication of abnormalities, then the sterilizer should be tested again in three consecutive cycles using paired biological indicators from different manufacturers to account for a possible defective biological indicator.

Which of the following would be an appropriate method to NOTES evaluate the quality of an infection prevention program? a. The total number of areas where surveillance was carried out in the past year b. The average amount of time that elapsed between receiving reports from the lab about patients with multidrug-resistant infections and placing those patient on appropriate Isolation Precautions c. The number of IPs in the program per the number of beds d. The average amount of money spent on isolation gowns this year as compared to last year

B. The average amount of time that elapsed between receiving reports from the lab about patients with multidrug-resistant infections and placing those patients on appropriate Isolation Precautions The quality of the infection prevention program should be assessed routinely by evaluating customer satisfaction, appropriateness, efficacy, timeliness, availability, effectiveness, and efficiency. The average amount of time that elapsed between receiving reports from the lab about patients with multidrug-resistant infections and placing those patients on appropriate Isolation Precautions relates to timeliness of initiating appropriate interventions. Therefore, it can be used as a quality measure for the program.

An IP conducts an audit of the OR cleaning process. The action that would be most concerning would be: a. The operating room is terminally cleaned at the end of each business day b. The decontamination process starts on the floor of the OR and works upward toward the lighting c. The cleaning solutions are prepared daily d. A wet vacuum and microfiber mop head are used to clean the OR floors

B. The decontamination process starts on the floor of the OR and works upward toward the lighting At the end of each day's operating schedule, a complete terminal cleaning program should be initiated to ensure that every operating room, scrub room, and service room is properly and thoroughly cleaned. The decontamination process begins at the highest level (i.e., light tracks, ceiling fixtures) and progresses downward (i.e., shelves, tables, kick buckets, and floor).

Which of the following scenarios would be most appropriate for immediate-use sterilization: a. The vendor brings the instrument for the procedure the morning of the surgery, which does not allow for the full sterilization process b. The instrument used for the procedure is dropped on the floor of the operating room and another instrument is not available c. The turnaround time between procedures does not allow enough time for the full sterilization process d. The OR does not have the needed instruments to meet the demand of surgeries so the instruments are flashed between procedures

B. The instrument used for the procedure is dropped on the floor of the operating room and another instrument is not available Flash sterilization is a quick-steam sterilization cycle that does not use the full sterilization cycle of exposure and dry times. Exposure may be abbreviated in gravity steam sterilizers by eliminating wrapping material or using container systems that ensure that the steam has unrestricted access to the instruments. The Association of Perioperative Registered Nurses' (AORN) Recommended Practices are consistent with the Association of Advancement in Medical Instrumentation (AAMI), which recommended that flash sterilization should be used only when there is an urgent need for the items.

Which of the following is an example of surveillance on a process indicator? a. The incidence rate of Clostridium difficile in the Bone Marrow Transplant Unit b. The rate of hand hygiene compliance in the Bone Marrow Transplant Unit c. The number of sharp object injuries in the month of May in the Bone Marrow Transplant Unit d. The prevalence of vancomycin-resistant enterococci (VRE) in the Bone Marrow Transplant Unit

B. The rate of hand hygiene compliance in the Bone Marrow Transplant Unit This is a process measure because it is measuring whether an action has taken place but not whether there is any effect of this action on outcomes.

Noninfectious postoperative endophthalmitis is most often associated with: a. Wearing contact lens b. Toxic anterior segment syndrome (TASS) c. Conjunctivitis d. Keratitis

B. Toxic anterior segment syndrome (TASS) Healthcare-associated endophthalmitis can be either noninfectious or infectious. Noninfectious endophthalmitis is an adverse event with several presenting causes, including retained lens material and other introduced toxic substances. Frequency is unknown, but occurrence is not rare. Noninfectious postoperative endophthalmitis is most often associated with TASS—an acute, rapid onset of sterile anterior segment inflammation that mimics infectious endophthalmitis. Outbreaks of TASS have been associated with breaches in handling, cleaning, and disinfecting surgical instruments; introduction of contaminated solutions, contaminated intraocular lenses, and toxic medications during surgery; powder from gloves; and irritants (dried blood, endotoxins, residual detergent) left on instruments.

The CDC has categorized bioterrorism agents according to priority. A disease that meets the criteria listed under Category B is: a. Anthrax b. Typhus c. Hantavirus d. Measles

B. Typhus Agents classified by CDC as Category A are biological agents that have high potential for adverse public health impact, increased risk to national security, serious potential for large-scale dissemination, potential for public panic, social disruption, and high mortality rates. Category B agents have a moderate ease in disseminating, specific requirements for disease surveillance, moderate morbidity rates, and low mortality. Typhus (Rickettsia prowazekii) meets the Category B criteria.

An IP is asked to participate in the selection of a company to reprocess single-use devices (SUDs). Before a decision is made on which reprocessing company will be used, the IP reviews available information from a variety of resources to assist with the decision making. Which of the following activities should the IP recommend the hospital undertake? a. Talk to other infection preventionists about which sterilizing methods to use on the SUDs b. Visit reprocessing companies under consideration c. Create quality control records for the SUDs d. Identify the patients on which the reprocessed SUDs, as opposed to new devices, will be used

B. Visit reprocessing companies under consideration Healthcare facilities that are considering contracting with a commercial third-party reprocessor must verify that reprocessing an SUD presents no greater risk to their patients' health and safety than using a new SUD. The decision to contract with a reprocessing company should be based on a thorough review and FDA approval of their 510(k) application. An onsite visit should be scheduled, with the opportunity to meet with personnel involved in the process, and a review of the company's policies. The visit should also include an opportunity to view the cleaning and decontamination, inspection and testing, and sterilization load preparation process, and to review quality control records.

The IP is monitoring blood work in order to differentiate between bacterial or viral infection in a newly admitted ICU patient. Which of the following components of a complete blood count (CBC) should the IP examine in order to determine this information? a. Hematocrit b. White blood cell count c. Platelet (thrombocyte count) d. Red blood cell indices

B. WBC A white blood cell (WBC) count and differential provide information about the relative numbers (that is, the percentage) of each type of WBC. Evaluation of the WBC count can help to determine whether an illness has a bacterial or viral origin.

A measles exposure from a patient in a clinic was identified and an exposure workup was initiated. A staff exposure was defined as "nonimmune HCP with more than 5 minutes of same-room contact or face-to-face contact with the index patient." Forty eight HCP were identified as possible exposures. Of these, 44 had documented immunity to measles. Of the remaining HCP, three did not have the same room or face-to-face contact. How many HCP were at risk of developing measles because of this exposure? a. 4 b. 45 c. 1 d. 48

C. 1 Measles is a highly contagious febrile exanthem. In most immunocompetent individuals, measles is a self-limited condition with a distinct clinical prodrome of cough, coryza, and conjunctivitis followed by a morbilliform skin eruption. Measles is more severe in young, malnourished, and immunocompromised persons. Even healthy individuals may experience complications, however, such as otitis media, bronchopneumonia, encephalitis, and laryngotracheobronchitis. Because measles is so highly contagious, healthcare facilities need to be prepared to safely care for measles patients. Measles immunity (natural or vaccinated) among HCP and use of proper isolation guidelines and postexposure protocols need to be established to minimize the potential for healthcare-associated transmission of measles. According to the definition of staff exposure, only one healthcare worker was nonimmune and had more than 5 minutes of same-room contact or face-toface contact with the index patient. Susceptible personnel who have been exposed to an individual with measles should be furloughed (relieved from healthcare activities) from the fifth to the 21st day after exposure, regardless of whether they received measles vaccine or immunoglobulin after exposure or until 4 days after development of rash. Personnel who develop measles should be furloughed until they have had their rash for 4 days.

An early-level (novice) IP in your department has set a goal of advancing to achieve middle-level (proficient) competency within the next year. Which of the following activities would be the most appropriate to include on her personal development plan for the year: 1) Nominating herself for the President-elect position of the local APIC chapter 2) Taking the Certification in Infection Control exam within six months 3) Requesting information about a Master of Science in Epidemiology degree 4) Learning the basics of CAUTI surveillance a. 1 b. 1, 2 c. 1, 2, 3 d. 1, 2, 3, 4

C. 1, 2, 3 APIC has created a competency model to help guide the advancement of infection preventionists in the field. The three levels of competency are early-level (novice), middle-level (proficient), and advancedlevel (expert). The competency levels can be used to guide goal setting activities as part of the IP's personal development plan. Middle-level competencies include being Certified in Infection Control, considering an advanced degree in the field, and being active in the local APIC chapter by serving in a leadership position.

An ambulatory clinic will be transporting equipment to the local hospital for sterilization. The IP at the clinic has been asked to write a policy to ensure safe handling of the equipment by staff. The policy should include which of the following points on handling the instruments at the point of use? 1) Devices are to be cleaned before biofilm can form 2) Keep instrumentation moist to prevent bio-burden from drying 3) Instruments with lumens should be flushed with saline 4) Contaminated devices are to be placed in a sealed container to prevent exposure to staff and patients a. 1, 3, 4 b. 2, 3, 4 c. 1, 2, 4 d. 1, 2, 3

C. 1, 2, 4 Reprocessing contaminated equipment or instruments for sterilization begins at point of use. The end user is responsible for removing gross soil and debris and for rinsing items at the site of use. Instruments with lumens should be flushed with water (not saline, as salt is corrosive to most instruments). Every attempt should be made to keep instrument or equipment surfaces moist until they can be cleaned to facilitate the removal of soil. Applying enzymatic foam or gel cleaner, using wet towels placed within the set of used instruments, or presoaking used items in water or cleaning solution may also be done. Contaminated items should be placed in puncture-proof sealable containers and visibly labeled as biohazardous.

Patients with mycoplasma pneumonia should be cared for NOTES in which type of precautions? 1) Standard Precautions 2) Airborne Precautions 3) Droplet Precautions 4) Contact Precautions a. 1, 2 b. 3, 4 c. 1, 3 d. 1, 4

C. 1, 3 Mycoplasma pneumonia is spread by respiratory droplets during close contact with a symptomatic person. In addition to Standard Precautions, Droplet Precautions are recommended for the duration of symptomatic illness.

Epidemic keratoconjunctivitis (EKC) is a viral conjunctivitis caused by a group of adenoviruses. EKC is highly contagious and can be problematic in ambulatory surgery settings. Recommended measures for control of these infections include: 1) Disinfection of tonometer tips in 3 percent hydrogen peroxide 2) Sterilize ophthalmoscopes between uses 3) Disinfection of the environment 4) Frequent hand hygiene a. 2, 3, 4 b. 1, 2, 4 c. 1, 3, 4 d. 2, 3, 4

C. 1, 3, 4 Prevention of EKC requires meticulous attention to hand washing. Soap and water and/or an alcohol-based hand sanitizer should be used before and after each patient contact. Gloves should be worn and discarded appropriately during outbreaks and when exposure to patient's tears or excretions is likely. The current CDC recommendations for disinfection of tonometer tips include a 5 to 10 minute soak in 3 percent hydrogen peroxide, 70 percent isopropyl, 70 percent ethyl alcohol, or in 5,000 ppm bleach. Ophthalmoscopes should be wiped with 70 percent alcohol between patients.

Which short-term central lines are associated with a higher risk of infection? 1) Peripherally-inserted central venous catheters (PICC) 2) Femoral lines 3) Subclavian lines 4) Jugular lines a. 1, 2 b. 2, 3 c. 2, 4 d. 1, 4

C. 2, 4 The CDC recommends using the subclavian site rather than a jugular or a femoral site in adult patients to minimize infection risk for nontunneled central venous catheter placement.

The safe temperature range for cold food storage is: a. 41°F/5°C or lower b. 42°F to 50°F/5.6°C to 10°C c. 50°F to 55°F/10°C to 12.8°C d. Less than 60°F/15.6°C

C. 41°F/5°C or lower Cold foods for serving must be held at 41°F/5°C or lower. The temperature danger zone is 41°F to 135°F/5°C to 57°C, which is the temperature range for rapid multiplication of virtually all bacteria associated with foodborne disease.

What is the acceptable upper limit for relative humidity in a facility to prevent fungal growth? a. 40 percent b. 50 percent c. 60 percent d. 70 percent

C. 60 percent Building materials contain fungal spores that have the potential to germinate in the correct conditions. Fungi require high relative humidity for growth, with most species needing relative humidity above 70 percent. Healthcare facilities should maintain relative humidity below 60 percent to prevent the growth of fungus and to provide a comfortable patient care environment.

A preliminary microbiology report states that a patient's blood culture grew aerobic, Gram-negative bacilli. Which of the following is the most likely genus and species of the organism: a. Enterococcus faecalis b. Bacteroides fragilis c. Acinetobacter baumanii d. Neisseria meningitides

C. Acinetobacter baumanii Acinetobacter baumannii is a Gram-negative bacterium. It is typically short, almost round, and rod-shaped (coccobacillus). It can be an opportunistic pathogen in humans, affecting people with compromised immune systems and is becoming increasingly important as an HAI. It has also been isolated from soil and water samples in the environment

A pregnant healthcare worker is concerned because she has been assigned to take care of a patient who has cytomegalovirus (CMV) infection. How should an IP respond to this concern? a. Reassign her to another patient b. Place the patient on Contact Precautions while the healthcare worker cares for him c. Advise her that following Standard Precautions while caring for the patient will prevent transmission d. Advise her that she is likely already infected with CMV and should not worry about transmission

C. Advise her that following Standard Precautions while caring for the patient will prevent transmission CMV is transmitted through saliva, urine, and blood products and organs. The CDC recommends using Standard Precautions when caring for patients with CMV, with no additional precautions recommended for pregnant HCP.

A nurse manager from a Rehabilitation Unit is requesting that aerators be installed on the sinks in the patient rooms on her unit. The IP should explain that: a. Aerators should be placed on all sinks in the ICU only b. Aerators are more effective when combined with an ultraviolet water disinfection method c. Aerators increase the risk of HAIs d. Low-flow aerators are suitable for use with this population

C. Aerators increase the risk of HAIs Various types of equipment and fixtures can promote the growth of water-associated pathogens. Important water reservoirs for these organisms include potable water systems and cooling towers, flush sinks, faucet aerators, hoppers and toilets, eyewash/drench shower stations, chests/ice machines, water baths used to thaw or warm blood products and other liquids, and whirlpool or spa-like baths. Faucet aerators on sinks can enhance growth of waterborne organisms. Aerators are not recommended, but if they must be used, especially in an area with immunocompromised patients, a systematic cleaning routine should be established.

An acute care facility experiences an outbreak of Serratia marcescens bloodstream infections. After the outbreak is under control and no new cases are being reported, the IP wants to find the source of the outbreak. The most appropriate epidemiology study design to use is: a. Retrospective cohort study b. Prospective cohort study c. Case-control study d. Cross-sectional study

C. Case control study Case-control studies group people by disease status and then investigate past exposures with the objective of identifying exposures that are more common to cases than to controls. This is an appropriate study design for this example because there are existing cases, and the IP is trying to identify the exposures that are associated with the bloodstream infections.

The IP receives a call from a physician who is concerned that there is an outbreak of Acinetobacter baumannii, because he has cared for four patients in the past week who are infected with the organism. What is the IP's first step in responding to this call? a. Contact the lab to ask them to create an alert for any A. baumannii cases b. Contact hospital administration to request additional resources to investigate the outbreak c. Confirm that there is an outbreak by using her own surveillance data and lab records to compare the rates of Acinetobacter baumannii over the past year d. Initiate a case-control study to determine risk factors for A. baumanii infection

C. Confirm that there is an outbreak by using her own surveillance data and lab records to compare the rates of Acinetobacter baumannii over the past year Confirming the presence of an outbreak is a key first step in an outbreak investigation

After reviewing the quarterly report, the manager of the adult ICU contacts the IP for assistance to create a plan to reduce central line infections. Which of the following should the IP recommend: a. Wait for the next report to see if the rate has decreased b. Create an Intravascular Team c. Develop a multidisciplinary team to review and implement best practices d. Send a referral to Medical Affairs for peer review

C. Develop a multidisciplinary team to review and implement best practices Multidisciplinary teams are a valuable tool in deploying a quality focused culture or process. Successful teams increase problem solving and efficiency, raise morale and productivity, use integrative rather than imposed solutions, increase acceptance of the solution, and tap the potential in people and their fundamental knowledge of the process.

Which of the following is not an infection prevention objective of an occupational health program? a. Contain costs by preventing infectious diseases that result in absenteeism and disability b. Provide care to personnel for work-related illnesses or exposures c. Educate patients about the principles of infection prevention d. Collaborate with the Infection Prevention Department in monitoring and investigating potentially harmful infectious exposures and outbreaks

C. Educate patients about the principles of infection prevention The healthcare organization's administration, medical staff, and other HCP need to support the infection prevention objectives of an occupational health program. These objectives are to (1) educate personnel about the principles of infection prevention and their individual responsibility for infection prevention, (2) collaborate with the Infection Prevention Department in monitoring and investigating potentially harmful infectious exposures and outbreaks, (3) provide care to personnel for work-related illnesses or exposures, (4) identify work-related infection risks and institute appropriate preventive measures, and (5) contain costs by preventing infectious diseases that result in absenteeism and disability.

While reviewing blood culture reports, you notice a note indicating that the specimen was received in the lab 3 hours after it was collected. You confirm with the microbiology supervisor. The acceptable transport time is: a. Place specimen on ice and transport within one hour of collection b. Within 24 hours of collection at room temperature c. Equal to or less than 2 hours at room temperature d. Equal to or greater than 4 hours if refrigerated

C. Equal to or less than 2 hours at room temperature The reliability and value of test results depends on numerous factors. Improper collection, transport, or processing of a specimen can decrease the quality of patient care or result in unnecessary additional testing or treatment. Blood Culture bottles must be transported to the Lab within a time frame equal to or less than two hours and must be maintained at room temperature.

The Director of the Infection Prevention and Control Department has assigned one of her IPs to cofacilitate in a root cause analysis of an adverse event in collaboration with the Performance Improvement team. The IP plans to use process improvement tools and techniques during the analysis. Which of the following methods would best outline the possible causes of the event? a. Brainstorming b. Affinity diagrams c. Fishbone diagram d. Pareto chart

C. Fishbone diagram A fishbone diagram (also called a tree diagram or Ishikawa) allows a team to identify, explore, and graphically display all of the possible causes related to a problem to discover the root cause. See Figure PE1-1 for an example.

Vaginal probes with probe covers require which type of disinfection: a. Low-level disinfection b. Intermediate-level disinfection c. High-level disinfection d. Sterilization

C. High-level disinfection Vaginal probes are used in sonographic scanning. A vaginal probe and all endocavitary probes without a probe cover are semicritical devices because they have direct contact with mucous membranes. It is recommended that a new condom/probe cover should be used to cover the probe for each patient and, because condoms/probe covers may fail, high-level disinfection of the probe should also be performed. These medical devices should be free of all vegetative microorganisms (i.e., mycobacteria, fungi, viruses, bacteria), though small numbers of bacterial spores may be present

The manufacturer of a wound dressing product has notified the hospital's Purchasing Department of possible contamination of one lot of dressings. The dressings were recently approved by the Product Standardization Committee and are used in all patient care areas. Which of the following actions should the IP take? a. Instruct the Purchasing Department to remove all the manufacturer's dressings and like products from the hospital b. Notify discharged patients who were using the product while in the hospital to be alert for signs of infection and notify their physician and the Infection Prevention and Control Department c. Identify where the dressings are in the hospital, check the lot number and return them to the manufacturer, and assess the patients who used the product for signs of infection d. Notify the Health Department of the recall and provide the names of the patients who used the product

C. Identify where the dressings are in the hospital, check the lot number and return them to the manufacturer, and assess the patients who used the product for signs of infection The U.S. FDA is the federal agency that is responsible for promoting public health through a number of activities, including the reasonable assurance that (1) food is safe, wholesome, sanitary, and properly labeled; (2) human drugs are safe and effective; (3) medical devices intended for human use are safe and effective; and (4) public health and safety are protected from electronic product radiation. Recalls are actions taken by a manufacturer/distributor to remove a product from the market. Recalls may be conducted on a manufacturer/distributor's own initiative (voluntary recall), by FDA request, or by FDA order. According to the FDA, a recall is a removal or correction of a product that is (1) defective; (2) a potential health risk; or (3) in violation of FDA regulations. The first step that the IP should take is to identify where the dressings are in the hospital, immediately remove them, and return them to the manufacturer. It is critical to assess the patients who used the product for signs of infection.

You are working with the antimicrobial stewardship program in your facility to educate providers on appropriate use of antimicrobials. Which of the following would be an accurate recommendation from your group? a. Metronidazole is an effective antimicrobial to use for MRSA skin infections b. Consistent use of broad-spectrum antimicrobials regardless of susceptibility results will help reduce antimicrobial resistance in the facility c. It is not always necessary to maintain antimicrobial concentration in the body above the level of the minimum inhibitory concentration of the pathogen being targeted d. Cefepime is only useful for gram-negative bacterial infections

C. It is not always necessary to maintain antimicrobial concentration in the body above the level of the minimum inhibitory concentration of the pathogen being targeted The minimum inhibitory concentration (MIC) of a drug is the lowest amount that can be used that will still be effective against the pathogen. The MIC is a quantitative measure of resistance of the microbe to a drug, obtained by some antimicrobial susceptibility testing methods, such as E-test. Drugs with concentration-dependent activity are most effective when they reach a high concentration in the blood over a short period of time. The concentration of these drugs will then fall below the MIC for a period of time but they are still effective, and they can be dosed once a day. This is in contrast to drugs with time-dependent activity that should be maintained consistently in concentrations above the MIC in the system and are administered with multiple or continuous doses.

A major difference between a prospective and a retrospective study is that the prospective study: a. Requires a relatively small number of subjects b. Is usually used for testing initial hypotheses c. May require a long follow-up period d. Is usually less costly

C. May require a long follow-up period A retrospective study looks backwards and examines exposures to suspected risk or protection factors in relation to an outcome that is established at the start of the study. Retrospective studies may be undertaken in a timelier and less-expensive manner than prospective cohort studies because cases may be identified retrospectively, and at least some exposure data are often available through medical record review. A prospective cohort study watches for outcomes, such as the development of a disease, during the study period and relates this to other factors such as suspected risk or protection factor(s). The study usually involves taking a cohort of subjects and watching them over a long period. Prospective studies usually have fewer potential sources of bias and confounding than retrospective studies.

Toys used for inpatient pediatric patients should ideally be all of the following except: a. New b. Nonporous c. Plush d. Single-patient use

C. Plush Strategies to minimize pediatric infection risk from toys include: • Practice of hand hygiene by patients before and after handling toys • Implementation of a process for appropriate toy acquisition to ensure suitability for cleaning/disinfection; toys should be nonporous and able to withstand rigorous mechanical cleaning. Avoid toys that are water retaining, plush, and stuffed (an exception is therapeutic dolls, which should be single-patient use); and those that are difficult to clean and dry. • Use of new toys

Herpes simplex virus (HSV) keratitis is suspected in an oncology patient. Aerobic eye cultures are negative to date. A single serum sample is sent for enzyme-linked immunosorbent assay (ELISA) antibody testing. The following titers are reported: HSV titer 1:128, cytomegalovirus (CMV) titer <1:8, Epstein-Barr virus (EBV) titer <1:8. These results indicate: a. Immunity to HSV b. Confirmation of acute HSV infection c. Presumptive identification of HSV infection d. Immunity to CMV and EBV

C. Presumptive identification of HSV infection The herpesviruses are a family of eight DNA viruses that initiate acute, chronic, and latent infections of the skin, epithelial cells, lymphocytes, and neurons. These include herpes simplex type 1 (HSV-1), herpes simplex type 2 (HSV-2), varicella-zoster virus, EBV, CMV, human herpesvirus 6 (HHV-6), human herpesvirus 7 (HHV-7), and human herpesvirus 8 (HHV-8). Herpesviruses are transmitted by close intimate contact or exposure to virus containing body fluids (saliva, urine, blood, breast milk, and contaminated respiratory or genital secretions). The reference range for HSV Type I or 2 IgM antibody is <1:10 negative; a result of 1:10 or greater is a positive result indicative of acute HSV infection.

The purpose of the antibiogram is to: a. Provide a monthly report on new and emerging antimicrobials b. Give IPs another metric to track c. Provide information on antimicrobial usage and resistance patterns in the community d. Give hospitals information needed for reporting data through the National Healthcare Safety Network (NHSN)

C. Provide information on antimicrobial usage and resistance patterns in the community The surveillance of antimicrobial resistance is an essential first step in identifying priority areas for managing antimicrobial use from an infection prevention perspective versus a pharmacy or cost-containment perspective. An antibiogram simplifies multiple patients' antimicrobial sensitivity information at an institution into a single number for pathogens of interest in an effort to monitor trends emerging in drug resistance. An antibiogram is a useful tool for the IP to determine the status of strategies in place to reduce MDROs

The IP receives a call from the Food and Drug Administration (FDA) with an official request for private health information (PHI) about a patient who was admitted to the facility with botulism. How should the IP respond to this call? a. Tell the FDA officer that she cannot share PHI with the FDA due to Health Insurance Portability and Accountability Act (HIPAA) regulations b. Ask the FDA to contact the local health department to obtain information about the patient c. Provide the FDA officer with the minimum amount of information necessary related to the patient d. Transfer the call to the Risk Management Department

C. Provide the FDA officer with the minimum amount of information necessary related to the patient The FDA is a public health authority. HIPAA regulations cover disclosure to the FDA of the minimum amount of information is necessary to prevent or control disease

The heating, ventilation, and air conditioning system will need to be shut down in one patient care unit of your hospital for repairs that are anticipated to take two hours. Which of the following protocols should be followed for this event? a. Relocate all patients to other units while the shut down is in progress b. Require all patients to wear a surgical mask while the shut-down is in progress c. Relocate immunocompromised patients if necessary and provide emergency back up ventilation or portable units for other rooms d. No protocol needs to be followed as the short shut down period will not affect any patients

C. Relocate immunocompromised patients if necessary and provide emergency back-up ventilation or portable units for other rooms Any shut-down of the HVAC must be coordinated with Infection Control to protect patient safety. Immunocompromised patients should be moved from the area if possible and an alternate ventilation method (emergency back-up or portable ventilation) should be used to maintain proper air flow in all rooms, including airborne isolation rooms and protective environments. Infection preventionists should be aware of the potential for a burst of spores from the HVAC when it is brought back online. In addition, critical areas will need to be given time for the appropriate number of air changes per hour to occur before they can be put back into regular use.

What action is indicated when the IP is asked to help determine if a worker has experienced occupational acquisition of an infectious agent or disease in order to receive workers' compensation benefit? a. Provide enough information to prove or disprove the employee's claim b. Notify the facility's attorney immediately c. Review the workers' compensation system in place d. Perform a root cause analysis to investigate

C. Review the workers' compensation system in place Disease that results from occupational exposure usually is eligible for compensation if the occupational exposure is the sole cause of disease; the occupational exposure is one of several causes of the disease; the occupational exposure aggravates a pre-existing disease (e.g., asthma); or the occupational exposure hastens the onset of disability. The burden of proving that disease was occupationally acquired lies with the workers. The IP's expertise may be needed to help assess this situation. Risk Management and Occupational Health provide the necessary follow-up. IPs should be familiar with the workers' compensation system in place within their country.

An IP has completed the investigation of an increase in postdischarge SSIs following ambulatory surgical procedures. He identified some corrective measures that will require monitoring. Which of the following actions should the Infection Prevention team take? a. Monitor the cleaning of the surgical suites b. Ensure the effectiveness of the ventilation system c. Revise the facility's surveillance plan d. Ensure that patient care equipment is adequately cleaned

C. Revise the facility's surveillance plan Surveillance activities should support a system that can identify risk factors for infection and other adverse advents, implement risk-reduction measures, and monitor the effectiveness of interventions. The items noted in answers A, B, and D are rarely related to the development of SSIs. The facility's surveillance program should be revised to reflect the current risks and risk reduction measures.

Which is an example of actions taken during the Study phase of the "Plan, Do, Study, Act" Performance Improvement Model? a. Identifying goals for the project b. Performing staff education sessions c. Trending and benchmarking of data collected d. Tweaking the program based on results

C. T rending and benchmarking of data collected TJC makes clear in the Infection Control and Prevention Standards that organizations should align the plan with the goal of improving infection rates. The organization must collect and display data to frontline staff about how well the organization actually achieves rate reduction. Data may include steps to increase staff influenza vaccination rates, reduce bloodstream infection and urinary catheter rates, and reduce rates of VAP. During the study phase of the cycle, data display, benchmarking, and trending become essential

Which of the following is not an advantage of a case-control study? a. It takes less time than a cohort study b. It requires fewer subjects c. The data are more accurate because it is prospective d. It is generally considered less expensive

C. The data is more accurate because it is prospective Case-control studies collect data retrospectively. Retrospective studies are used to get information about past events and are subject to recall bias because they rely on the memory of subjects and others for information on exposure.

To calculate the catheter-associated urinary tract infection (CAUTI) rate for a unit for one month, the denominator should be: a. The number of patient days for the unit for the month b. The number of admissions for the unit for the month c. The number of patients with urinary catheters for the month d. The number of urinary catheter insertions for the month

C. The number of patients with urinary catheters for the month There are three important aspects of the formula in determining the CAUTI rate: (1) persons in the denominator must reflect the same population from which the numerator was taken; (2) counts in the numerator and denominator should cover the same time period; and (3) the persons in the denominator should have been at risk of the event or occurrence (that is, number of patients with urinary catheters

Fifteen persons were infected with Salmonella at a picnic where 75 ate egg salad sandwiches. What was the attack rate of Salmonella among those who ate the egg salad sandwiches? a. 15 percent b. 0.20 percent c. 18 percent d. 20 percent

D. 20 percent An attack rate is a special form of incidence rate. In fact, it is not truly a rate but a proportion. It is the proportion of persons at risk who become infected over an entire period of exposure or a measure of the risk or probability of becoming a case. It is usually expressed as a percentage and is used almost exclusively for epidemics or outbreaks of disease where a specific population is exposed to a disease for a limited period of time. The attack rate for this scenario is calculated as follows: 15 ÷ 75 × 100 = 20 percent.

In a published report on the risk of VRE infection in ICUs of a major teaching hospital, the authors report that the relative risk of infection is 1.9 for the Cardiac ICU (CICU) when compared to the SICU, and they conclude that a stay in the CICU is a risk factor for VRE infection. The authors have not controlled for age in their study despite the fact that their CICU patients average 20 years older than their SICU patients, and older age is a risk factor for VRE infection. The IP is concerned about the conclusions of this study because he suspects which of the following? a. The study is affected by selection bias b. The study is affected by standard error c. The study is affected by confounding d. The study is affected by causation

C. The study is affected by confounding A confounding variable is an extraneous variable (i.e., a variable that is not a focus of the study) that is statistically related to (or correlated with) the independent variable. This means that as the independent variable changes, the confounding variable changes along with it. The result is that subjects in one condition are different in some unintended way from subjects in the other condition. Confounding can lead to the assumption that there are differences that do not really exist or to the observation that there is no difference when one truly exists. In this example, older age is associated with the risk factor of a CICU stay and with the outcome of VRE infection. The authors did not adjust for age in their study, so the IP should be concerned that the reported association is confounded by age.

In a Gram stain procedure, Gram-positive bacteria stain purple because: a. They have a lipopolysaccharide layer in their cell wall that is decolorized with alcohol b. Their cell walls contain long-chain fatty acids that take up crystal violet easily c. They have a thick peptidoglycan cell wall that retains the primary stain during the alcohol decolorization d. Gram-staining is simple staining so the only stain used is crystal violet

C. They have a thick peptidoglycan cell wall that retains the primary stain during the alcohol decolorization Gram-positive cells will take up the initial crystal violet stain and will not be decolorized with alcohol because their peptidoglycan cell walls are thick enough to resist decolorization.

The "epidemiologic triangle" model for disease causation does not include: a. Agent b. Host c. Time d. Environment

C. Time The "epidemiological triangle" model of disease (see Fig. PE1-2) consists of three elements: host, agent, and environment. The host is the human, and the environment consists of all external factors associated with the host. The agent may be a bacteria, virus, fungus, protozoan, helminth, or prion. In this model of dynamic interaction, a change in any component alters the existing equilibrium. Change may increase or decrease the frequency of disease. Although this model is particularly useful in the study of infectious diseases, it is also applicable to other conditions

Which of the following are CDC requirements for storing endoscopes? 1) Store them coiled in the original case 2) Store them in a bin 3) Store hanging in a vertical position to facilitate drying 4) Store in a manner that protects the scope from contamination a. 1, 4 b. 1, 2 c. 2, 3 d. 3, 4

D. 3, 4 Endoscopes should be stored in a manner that protects them from contamination. When storing the endoscope, hang it in a vertical position to facilitate drying (with caps, valves, and other detachable components removed as per manufacturer instructions).

Which U.S. agency requires a respiratory program for HCP? a. Food and Drug Administration (FDA) b. The Joint Commission (TJC) c. Centers for Disease Control and Prevention (CDC) d. Occupational Safety and Health Administration (OSHA)

D. Occupational Safety and Health Administration (OSHA) The OSHA respiratory protection standard requires that the employer implement a respiratory protection program with a qualified administrator as the person who oversees the program, including evaluating the effectiveness of the program. The standard also requires that each worker assigned to wear a respirator receive a fit test before wearing the respirator in the workplace and perform a seal check with each use.

The IP at a long-term acute care (LTAC) facility is reviewing her surveillance data. Due to the high-risk nature of the LTAC's patient population, infection control data include a large number of outliers. Which measure of central tendency is least affected by outliers? a. Proportions that include the population in the numerator and a subset of the population in the denominator b. Proportions that include the population in the denominator and a subset of the population in the numerator c. Arithmetic mean d. Median

D. The median is the point at which 50 percent of the values fall below a middle value and 50 percent of values occur above the middle value. It is the midpoint of the observations. The median ignores extreme values and is better at indicating values close to an average.

All of the 72 patients in a chronic hemodialysis center were tested for Hepatitis C virus (HCV). Eight of the patients were identified as HCV positive. What is the prevalence? a. 0.9 percent b. 9 percent c. 1 percent d. 11 percent

D. 11 percent A prevalence rate is the proportion of persons in a population with a particular disease or attribute at a specific point in time (point prevalence) or over a specified time period (period prevalence). Prevalence depends on the duration of disease. The prevalence rate equals the number of existing cases of disease from a specified interval or point in time divided by the population at risk for same time period multiplied by a constant (k). k = A constant used to transform the result of division into a uniform quantity so that it can be compared with other, similar quantities. A whole number (fractions are inconvenient) such as 100, 1,000, 10,000, or 100,000 is usually used (selection of k is usually made so that the smallest rate calculated has at least one digit to the left of the decimal point) or is determined by accepted practice (the magnitude of numerator compared with denominator). This prevalence rate is calculated as: 8 ÷ 72 × 100 = 11 percent

A staff nurse informs the IP that a patient with confirmed multidrug-resistant TB requires an immediate bronchoscopy. In which of the following rooms must the procedure be performed? a. The operating room under positive pressure b. Standard procedure room in the endoscopy suite c. The ICU with direct exhaust to the outside d. Airborne infection isolation room

D. Airborne infection isolation room Bronchoscopy permits direct visualization of airways using a fiberoptic bronchoscope and is used in the diagnosis and management of inflammatory, infectious, and malignant diseases of the chest. Bronchoscopy should not be performed on patients with TB unless absolutely necessary. If medically necessary, bronchoscopy should only be performed in a room that meets the ventilation requirements for an airborne infection isolation room (negative directional air flow, a minimum of 12 air exchanges per hour and direct exhaust to the outside more than 25 feet from an air intake or discharged through a high efficiency particulate air filtration system).

All of the following may be indications of a heating, ventilation, and air conditioning (HVAC) malfunction except: a. An increase in the postoperative surgical site infection (SSI) rates b. A single case of aspergillosis in a severely immunosuppressed patient c. Healthcare-associated varicella infections d. An outbreak of ventilator-associated Acinetobacter infections in the Intensive Care Unit (ICU)

D. An outbreak of ventilator-associated Acinetobacter infections in the Intensive Care Unit (ICU) Detection and identification of certain HAIs may suggest HVAC malfunction (e.g., healthcare-associated tuberculosis, single case of aspergillosis in a severely immunosuppressed patient, healthcare-associated varicella infections). Analysis of postoperative SSI rates and associated infectious agents may offer important clues to problems in the OR air system(s). HVAC systems are usually not the immediate cause of device associated HAIs.

Which of the following is an example of the principle of emergency management called "mitigation?" a. Implementation of the hospital's emergency management plan during a hurricane b. Recovery efforts after a major flood has subsided c. A facility-wide bioterrorism disaster drill d. Funding a program that will provide ring vaccination of exposed people against smallpox during an outbreak

D. Funding a program that will provide ring vaccination of exposed people against smallpox during an outbreak Disasters should be planned for and responded to using the principles of emergency management. Emergency management is composed of four principles: mitigation, preparedness, response, and recovery. Mitigation describes actions taken to decrease the potential impact of a situation. These include interventions to either prevent or reduce morbidity and mortality and ease the economic and social impact of the event on the affected community. Funding a program that will provide ring vaccination of exposed people against smallpox during an outbreak is an example of mitigation because the activity will help prevent further morbidity and mortality.

A robust Performance Improvement team should perform all of the following except: a. Observational audits b. Benchmark comparisons c. Root cause analyses d. Housewide infection rates

D. Housewide infection rates A robust performance improvement program should include the following basic elements: measuring how a facility or organization controls or complies with policies; documenting results of observational audits; performing root cause analyses; reporting individual physician or unit infection rates; and benchmarking the organization's infection rate against community, state, and national averages.

The purpose of a root cause analysis is to: a. Determine which individual made an error so that the employee may be disciplined or terminated b. Review the basic processes that are in place and then turn that review over to a unit-specific team so that they can determine how they should modify their practices c. Provide a process that requires little time or training but allows employees to identify culpability after an adverse event d. Include participants from diverse areas of the organization to delve into the cause of an error or systems failure and identify changes in practice and/or policy that will prevent a repeat of that error or event

D. Include participants from diverse areas of the organization to delve into the cause of an error or systems failure and identify changes in practice and/or policy that will prevent a repeat of that error or event The root cause analysis process takes a retrospective look at adverse outcomes and determines what happened, why it happened, and what an organization can do to prevent the situation from recurring. Risk managers commonly use the root cause analysis to investigate major incidents, sentinel events, or errors in healthcare delivery. The root cause analysis process avoids individual blame, considers human factors engineering, and analyzes redesign for a safer system. When conducting root cause analysis, a multidisciplinary team discovers basic and contributing causes for what happened. The team includes frontline staff, and individuals most familiar with the situation to dig deep into the process, asking why something happens at each level of cause and effect. The entire root cause analysis process identifies changes to a particular process or system that improves safety or reduces process error. A thorough root cause analysis determines: (1) human and other factors; (2) the process or system involved; (3) underlying causes and effects of the process; and (4) the risks and potential contributions to failure or adverse results.

When using a medication vial that is intended to be discarded after a single procedure, it is acceptable to reuse the same syringe that was just used to access that vial and give that patient medication if: a. The needle is replaced with a new needle b. The medication vial is a single-use vial c. The vial is only going to be used for that patient d. It is not acceptable to reuse the syringe

D. It is not acceptable to reuse the syringe While the medication in this example is expected to only be used on one patient, a healthcare worker should still use a new, sterile syringe and needle to access the medication vial the second time. This is a precaution in the event that the vial does not get discarded after use on this one patient and instead is accidentally used on another patient.

The director of critical care has expressed a concern that there seems to be an increase in contaminated blood culture results in the ICU. An acceptable contamination level for blood cultures is: a. Less than 10 percent b. Greater than 3 percent c. Greater than 5 percent d. Less than 3 percent

D. Less than 3 percent Rationale: Bacteremia is a significant cause of morbidity and mortality in hospitalized patients. Accurate and timely identification of the causative organism is imperative. Blood cultures are considered the "gold standard" in the diagnosis and treatment of bacteremia. However, the prognostic value of blood cultures is limited by contamination. Contamination, or false positive blood cultures, occurs when organisms that are not present in the blood are grown in culture. Blood culture contamination rates of less than 3 percent are desired.

The most common organism associated with pneumonia in school-aged children and young adults is: a. Neisseria meningitidis b. Streptococcus pneumoniae c. Staphylococcus aureus d. Mycoplasma pneumoniae

D. Mycoplasma pneumoniae Mycoplasma is uncommon under the age of 5 but is the leading cause of pneumonia in school-aged children and young adults. It can occur during any season and occurs throughout the world.

The Director of the Operating Room (OR) requests that the OR surfaces be routinely environmentally cultured. The IP's best response should be: a. A schedule for routine culturing of the OR should be arranged so that each room is cultured at a set interval b. Routine culturing of the OR should be done in the absence of any epidemiologic investigations in that area c. Routine culturing should not be done because it is too expensive d. Routine environmental culturing should not be considered unless an epidemiologic investigation is being conducted

D. Routine environmental culturing should not be considered unless an epidemiologic investigation is being conducted Microbiological environmental testing is not generally recommended. Environmental culturing can be costly and may require special laboratory procedures. Additionally, in most cases no standards for comparison exist. Because of the lack of standards, environmental testing may generate inconclusive data that could result in the implementation of unnecessary procedures or treatment. Rationale for special environmental monitoring should be carefully planned and limited to epidemiological investigations. In limited situations, "routine" environmental sampling may be indicated.

Which method of face-to-face instruction is a useful option when large numbers of staff must be educated over a relatively short span of time? a. Role play b. Mentoring c. Case studies d. Train the trainer

D. Train the trainer Train the trainer is an option for face-to-face institutional training when large numbers of staff must be quickly educated. Leader guides are used to train those responsible for implementing the program and for providing staff inservice and continuing education. These leader guides should be simply written, concise, and systematic. They should include curriculum goals and objectives, the course outline, instructional methods, references, and evaluation. Role playing is often used to allow the learner to experience a professional dilemma firsthand. Mentors may be used as a way to upgrade and cross-train workforce. Case studies are viewed as an effective method to help bridge the learning gap between theory and actual practice.

Urinary tract infections in the postpartum period have three important risk factors. Which of the following is not one of them: a. Induction of labor b. Tocolysis c. Cesarean delivery d. Twin births

D. Twin Births Urinary tract infections (UTIs) in the postpartum period have three important risk factors: cesarean delivery, tocolysis, and induction of labor. Twin births are not associated with an increased risk of UTI.

What is the first action HCP should take after a needlestick exposure? a. Contact the supervisor b. Contact Occupational Health c. Squeeze or milk the site d. Wash the affected area

D. Wash the affected area The first action after exposure involves an immediate cleaning of the exposed/injured site. A soap-and-water hand wash should be performed to remove visible soil. Alcohol is virucidal, so an alcohol-based hand hygiene agent can be used after soap-and-water hand wash has been performed. Caustic chemicals such as bleach should not be used in an attempt to disinfect or cleanse the skin. Squeezing or "milking" the injured site is not necessary. Once the area has been washed, evaluation by a skilled professional should be sought.

A patient is suspected of having Pertussis. A nasopharyngeal aspirate is collected for direct fluorescent antibody (DFA) testing and for culture eight hours after antimicrobial therapy is started. The DFA test is negative but the culture test is positive. Does this patient have Pertussis? a. No, because the DFA test is highly specific and it was negative b. No, because culture of Bordatella pertussis has very low sensitivity c. No, because all testing is unreliable if antimicrobial therapy has been initiated prior to specimen collection d. Yes, because the culture test is 100 percent specific for identification of Bordatella pertussis

D. Yes, because the culture test is 100 percent specific for identification of Bordatella pertussis Pertussis is caused by the bacterium Bordatella pertussis. Diagnosis may occur by culture, DFA, or polymerase chain reaction testing. Culture of B. pertussis is carried out on Bordet-Gengout or Regan-Lowe media with nasopharyngeal samples and has varying sensitivity depending on specimen handling and whether antimicrobial therapy was initiated prior to specimen collection. DFA testing is very specific but not very sensitive, and PCR testing has good sensitivity and variable specificity. A negative DFA test may not mean that a patient doesn't actually have pertussis because this test has low sensitivity and thus there is a chance of false negative tests, so a culture test must be performed to confirm DFA test results. If the culture test is negative then this cannot rule out pertussis because culture may have low sensitivity, but if a culture test is positive then the patient has pertussis because the 100 percent specificity of the test means that there are no false positive results.

A major hurricane is forecast for your area and you need to plan for the possible contamination of potable water that is supplied to your facility. Which of the following should be included in your planning? a. You should have at least one day's worth of back up water supplies available b. You will need one liter per day of drinking water for all patients and healthcare workers c. All back up water must be stored on site for easy access d. You will need at least 25 gallons of water per patient per day to maintain care

D. You will need at least 25 gallons of water per patient per day to maintain care In the event of a disaster, it is critical to ensure that there is a reliable supply of water available for drinking and for patient care activities. Individuals in the facility will need at least 2 liters of drinking water per day per person, and additional water will be needed for bathing, flushing toilets, dialysis, cooking, and other activities. It is estimated that a facility will need 25 gallons of water per patient per day to maintain these patient care activities. Water may be stored on-site or off-site but it must be accessible in the event of an emergency.

The bacterium most likely to be transmitted from mother to infant during labor and cause neonatal sepsis is: a. Escherichia coli b. Staphylococcus aureus c. Group B Streptococcus d. Group A Streptococcus

Group B Streptococcus In Group B Streptococcus (GBS) neonatal infections, heavy maternal colonization is associated with an increased risk for preterm labor, which in turn is a significant risk factor for neonatal infection. Intrauterine infection of the fetus therefore likely occurs via ascending spread of GBS from the vagina of a pregnant, asymptomatically colonized woman and subsequent rupture of membranes before 37 weeks' gestation.

The following blood culture result should be considered a potential contaminant: a. A positive result of coagulase-negative staphylococci from two sets, 2 days apart, without symptoms b. A positive result of S. aureus from one bottle in a patient with a temperature of 38.6°C c. A positive result of E. coli from one bottle in an afebrile patient with diarrhea d. A positive result of Candida albicans in a fungal blood culture in a patient with a urinary tract infection

a. A positive result of coagulase-negative staphylococci from two sets, 2 days apart, without symptoms According to the CDC CLABSI criteria, common commensals (such as coagulase-negative staphylococci) meet the criteria for a CLABSI if there are two positive cultures from two or more sets of blood cultures drawn less than 2 days apart and the patient has symptoms (fever greater than 38°C, chills, or hypotension). CDC CLABSI criteria: Patient has at least one of the following signs or symptoms: fever (greater than 38°C), chills, or hypotension and positive laboratory results are not related to an infection at another site. And the same common commensal (i.e., diphtheroids [Corynebacterium spp. not C. diphtheriae], Bacillus spp. [not B. anthracis], Propionibacterium spp., coagulase-negative staphylococci [including S. epidermidis], viridans group streptococci, Aerococcus spp., and Micrococcus spp.) is cultured from two or more blood cultures drawn on separate occasions. Criterion elements must occur within a time frame that does not exceed a gap of 1 calendar day between two adjacent elements.

Which of the following is an example of the criterion of "Strength of the Association" from Hill's criteria for causation? a. In a study of the association between antibiotic exposure and development of C. difficile infection, the odds ratio was 2:3 b. In a study of the association between antibiotic exposure and development of C. difficile infection, the authors' conclusions are consistent with those of three other studies c. In a study of the association between antibiotic exposure and development of C. difficile infection, antibiotic therapy began an average of 3 weeks before C. difficile infection developed d. In a study of the association between antibiotic exposure and development of C. difficile infection, prolonged antibiotic therapy was a greater risk factor for C. difficile infection than short-term antibiotic therapy

a. In a study of the association between antibiotic exposure and development of C. difficile infection, the odds ratio was 2:3 Causal associations exist when evidence indicates that one factor is clearly shown to increase the probability of the occurrence of a disease. In a causal relationship, the reduction or diminution of a factor decreases the frequency of the disease being studied. The criteria currently used for causality were developed by Austin Bradford Hill and are known as Hill's criteria. These criteria use modern epidemiological methods to determine whether a factor is causal for a given disease. Strength of association is the first criterion: The incidence of disease should be higher in those who are exposed to the factor under consideration than in those who are not exposed; that is, the stronger the association between an exposure and a disease, the more likely the exposure is to be causal. The odds ratio is a statistical measure that gives us an indication of how strongly the risk factor is associated with the disease outcome.

Sensitivity may be defined as: a. The ability of a test to detect true positives (persons with the disease) when applied to a population with the disease b. The ability of a test to detect the true negatives (persons without the disease) when applied to a population without the disease c. The ability of a test to detect true positives (persons with disease) when applied to a population without the disease d. The percentage of persons with true positive results when the test is applied to persons without the disease

a. The ability of a test to detect true positives (persons with the disease) when applied to a population with the disease Rationale: Sensitivity and specificity are common statistical measures to describe diagnostic tests or presence of disease. Sensitivity is the ability of a test to identify true cases or persons who have the disease or health condition of interest. In other words, it is the probability of getting positive test results among patients with disease. A high sensitivity test means that a negative result rules out the disease

What type of meningitis would be most consistent with the following cerebrospinal fluid (CSF) report result: Glucose = decreased Protein = Elevated WBC counts = 1000/mm^3 a. bacterial b. viral c. fungal d. tuberculosis

a. bacterial Culture of blood and CSF are indicated for patients with suspected invasive meningococcal disease. The CSF of patients with untreated meningococcal meningitis is usually cloudy and has pleocytosis with a predominance of neutrophils, low glucose, and high protein levels. In most of the cases, the organisms are seen on Gram stain or can be identified using latex agglutination assays. The culture is almost invariably positive as long as the sample was obtained before the administration of antibiotics

Which of the following rules should be followed when collecting a stool sample for C. difficile testing? 1) Stool sample should be freshly passed within 1-2 hours 2) 10-20mL. of formed stool should be collected 3) Stool should be passed into a clean, dry container 4) Specimens should be obtained before antimicrobial agents have been administered a. 1, 2 b. 2, 3 c. 1, 3 d. 1, 4

c. 1, 3 The accuracy of all tests depends on proper specimen handling and transport. The following rules should be followed when collecting samples for C. difficile testing: • Stool samples should be freshly passed within 1-2 hours • 10-20 mL of watery, soft, or unformed stool should be collected • Stool should be passed into a clean, dry container