HW 16: Ch 16 & 19

Refer to comphrension: ignaz semmelweis & disinfection Approximately what proportion of women developed puerperal fever in Dr. Klein's ward once medical personnel started washing their hands? A. 18% B. 6% C. 6 D. 4% E. 18

B. 6%

Look to the C. aureus figure How many patients were initially identified with C. auris colonization in the U.S.? A. 390 B. 77 C. 77% D. 122 E. 35

B. 77 Explanation: 53+16+4+1+1+1+1 = 77.

Look to the C. aureus figure What percentage of the C. auris isolates sent to the CDC were resistant to fluconazole? A. 0.875% B. 85.7% C. 38.9% D. 24.6% E. 7.9%

B. 85.7% Explanation: 30 of the 35 tested strains were resistant to this medication. The math is 30/35 x 100 = 85.7%

Look to the C. aureus figure Which of the following were NOT tested for C. auris in this case? (NOTE: Please change all question marks to checkmarks for correct answers or empty boxes for incorrect answers.) A. Ears B. Eyes C. Urinary catheters D. Cerebrospinal fluid E. Wounds F. Stool samples G. Blood H. Armpits I. Nasal membranes

B. Eyes C. Urinary catheters D. Cerebrospinal fluid F. Stool samples

Refer to comphrension: ignaz semmelweis & disinfection How did Semmelweis test his hypothesis? A. He insisted that all women in childbirth were assisted by physicians or medical students, but not by midwives. B. He insisted that physicians and medical students wash their hands with disinfectant before aiding women in childbirth. C. He insisted that all women in childbirth were assisted by doctors, nurses or midwives, but not by medical students. D. He insisted that medical students should not dissect cadavers and also deliver babies on the same day. E. All of these choices are correct.

B. He insisted that physicians and medical students wash their hands with disinfectant before aiding women in childbirth.

Please select all the examples that involve direct transmission of infectious disease. (NOTE: Please change all question marks to checkmarks for correct answers or empty boxes for incorrect answers.) A. Food, water B. Kissing C. Fomites D. Touching E. Droplet spread F. Air G. Insects

B. Kissing D. Touching E. Droplet spread

Look to the C. aureus figure Which medication/class of medication do you think would most likely be prescribed for the 77 patients in this case? A. An echinocandin B. Amphotericin B C. Fluconazole D. Penicillin E. Penicillin with flucanozole

A. An echinocandin Explanation: So far, most strains of C. auris are still susceptible to this class of antifungal medication in the U.S. In this case, only 3% of the tested isolates were resistant to echinocandins.

Which of the following are reasons that made smallpox virus a good target for eradication? (NOTE: Please change all question marks to checkmarks for correct answers or empty boxes for incorrect answers.) A. Human beings were the only reservoir for the virus. B. There was only a single animal reservoir for the virus. C. The symptoms of the disease were highly evident and obvious. D. An effective vaccine was able to be produced and administered across the globe. E. Administration of the live attenuated vaccine to the U.S. population only gradually led to immunization of the rest of the world as Americans traveled abroad. F. Obviously infected individuals were able to be quarantined quickly to prevent spread of the infection to other susceptible individuals. G. Low levels of mortality induced by the disease gradually left most of the global population immune to reinfection. The virus burned itself out.

A. Human beings were the only reservoir for the virus. C. The symptoms of the disease were highly evident and obvious. D. An effective vaccine was able to be produced and administered across the globe. F. Obviously infected individuals were able to be quarantined quickly to prevent spread of the infection to other susceptible individuals.

Which of the following statements about symbiosis are FALSE? (NOTE: Please change all question marks to checkmarks for correct answers or empty boxes for incorrect answers.) A. Parasites are not in a symbiotic relationship with their host. B. Members of a symbiotic relationship cannot live independently. C. Symbiosis refers to organisms living together. D. The malaria pathogen Plasmodium vivax lives in a symbiotic relationship with its host. E. Only one partner in a symbiotic relationship is benefited.

A. Parasites are not in a symbiotic relationship with their host. B. Members of a symbiotic relationship cannot live independently. E. Only one partner in a symbiotic relationship is benefited.

Refer to comphrension: ignaz semmelweis & disinfection What did Semmelweis hypothesize? A. Physicians and students were inadvertently transferring something from cadavers to women in labor that caused illness and sometimes death in the women. B. Women giving birth in a hospital setting would be less likely to have complications than those giving birth at home with the assistance of a midwife. C. Medical students should never be allowed to assist in childbirth; they should be limited to dissecting cadavers. D. Women giving birth assisted by midwives would be more likely to fall ill during the process than those being aided by physicians or medical students. E. Women giving birth assisted by midwives would be more likely to survive than those being assisted by physicians and students, who killed most of their patients.

A. Physicians and students were inadvertently transferring something from cadavers to women in labor that caused illness and sometimes death in the women.

Refer to comphrension: ignaz semmelweis & disinfection Which of the following observations led Semmelweis to his hypothesis? (NOTE: Please change all question marks to checkmarks for correct answers or empty boxes for incorrect answers.) Check All That Apply A. Semmelweis's friend cut himself with a scalpel being used for an autopsy and developed the same signs and symptoms as women with puerperal fever. B. Women in childbirth aided by medical students who also did autopsies developed puerperal fever more often than those being aided by midwives who did no autopsies. C. Women in childbirth aided by doctors developed puerperal fever much more often than those aided by medical students. D. Women in childbirth aided by midwives who did autopsies developed puerperal fever less often than those being aided by medical students who did no autopsies. E. Semmelweis's friend cut himself with a scalpel being used for an autopsy and developed

A. Semmelweis's friend cut himself with a scalpel being used for an autopsy and developed the same signs and symptoms as women with puerperal fever. B. Women in childbirth aided by medical students who also did autopsies developed puerperal fever more often than those being aided by midwives who did no autopsies.

Refer to Clinical Case Study: Pseudomonas aeruginosa Which of the following did the first 10 patients have in common? (NOTE: Please change all question marks to checkmarks for correct answers or empty boxes for incorrect answers.) A. They had all undergone cardiovascular surgery. B. All patients had their surgery in the same operating room. C. The same surgeon operated on all patients. D. The patients all received post-operative care by the same nursing team. E. The patients all received a TEE. F. The patients were all exposed to the same TEE probe gel. G. The patients had identical types of cardiovascular surgery.

A. They had all undergone cardiovascular surgery. E. The patients all received a TEE. F. The patients were all exposed to the same TEE probe gel.

Refer to Clinical Case Study: Pseudomonas aeruginosa What was the role of the FDA in this case? A. To disseminate information and advice to facilities using ultrasound gel in TEE procedures. B. To perform molecular analysis on respiratory secretions from patients who had undergone a TEE. C. To identify patients colonized with Pseudomonas aeruginosa following a TEE procedure. D. To identify the source of the Pseudomonas aeruginosa colonizing the patients who had cardiovascular surgery. E. To monitor health care personnel working in the operating room and the ICU at the facility involved in this case.

A. To disseminate information and advice to facilities using ultrasound gel in TEE procedures.

Highly contagious diseases (diseases that spread easily) often/always have a high case fatality rate. (T/F)

False

Refer to comphrension: ignaz semmelweis & disinfection Semmelweis won the Nobel prize for his work. (T/F)

False

Viral Regulation of Apoptosis - Some viruses are capable of regulating apoptosis, inhibiting the interferon response and interfering with antigen presentation. (T/F).

False

Refer to Clinical Case Study: Pseudomonas aeruginosa Place the events/steps in this epidemiological study into the correct order in which they occurred/were carried out from 1-10. An unsuccessful effort was made to culture P. aeruginosa from surgical sites and blood of the 10 patients. The hospital replaced multi-use probe gel containers with sterile, single-use containers. TEE was the common factor in the cases of patients testing positive for the same strain of P. aeruginosa. An increase in positive respiratory cultures from a surgical intensive care unit was noted. Investigators examined what the 10 patients had in common, including type of surgical procedure. Pseudomonas aeruginosa was identified in secretions from endotracheal tubes in 10 patients. The investigation was expanded to identify other patients placed on ventilators during their surgery. Six out of an additional 20 ventilated patients at the facility were confirmed as having P. aeruginosa. The FDA was alerted and issued a Safety Communication to other healthcare facilities. A particular strain of P. aeruginosa was identified in the gel used to coat TEE probes.

1. An increase in positive respiratory cultures from a surgical intensive care unit was noted. 2. Pseudomonas aeruginosa was identified in secretions from endotracheal tubes in 10 patients. 3. An unsuccessful effort was made to culture P. aeruginosa from surgical sites and blood of the 10 patients. 4. Investigators examined what the 10 patients had in common, including type of surgical procedure. 5. The investigation was expanded to identify other patients placed on ventilators during their surgery. 6. Six out of an additional 20 ventilated patients at the facility were confirmed as having P. aeruginosa. 7. TEE was the common factor in the cases of patients testing positive for the same strain of P. aeruginosa. 8. A particular strain of P. aeruginosa was identified in the gel used to coat TEE probes. 9. The hospital replaced multi-use probe gel containers with sterile, single-use containers. 10. The FDA was alerted and issued a Safety Communication to other healthcare facilities.

Refer to Clinical Case Study: Pseudomonas aeruginosa Select the true statements regarding the transesophageal echocardiogram procedure in this study. (NOTE: Please change all question marks to checkmarks for correct answers or empty boxes for incorrect answers.) A. TEE is used during cardiovascular surgery because it allows the surgeon to visualize the lungs during the procedure. B. TEE involves using a probe that is inserted into the esophagus. C. The longer the TEE probe was in place in this study, the higher the patient's risk of contractingP. aeruginosa. D. The TEE probe gel used in this case was sterile. E. All of the patients who tested positive for P. aeruginosa in this case had also received a TEE. F. The P. aeruginosa found in the TEE probe gel was unrelated to the bacteria found in the respiratory tracts of the patients in this case.

B. TEE involves using a probe that is inserted into the esophagus. C. The longer the TEE probe was in place in this study, the higher the patient's risk of contracting P. aeruginosa. E. All of the patients who tested positive for P. aeruginosa in this case had also received a TEE.

Refer to comphrension: ignaz semmelweis & disinfection What is the main point of this reading? A. Cadavers carry poisons that cause illness and frequently death in women giving birth in the hospital. B. The incidence of bacterial infections in women giving birth is greatly reduced if medical personnel wash their hands before touching patients. C. Midwives are more successful in delivering babies safely than are doctors and medical students. D. Ignaz Semmelweis was a Hungarian doctor who worked in maternity hospitals in Vienna. E. By the mid-1800s, one in eight women giving birth in hospitals rather than at home contracted life-threatening infections.

B. The incidence of bacterial infections in women giving birth is greatly reduced if medical personnel wash their hands before touching patients.

Refer to Clinical Case Study: Pseudomonas aeruginosa What was the source of the P. aeruginosa in this case? A. Transesophageal echocardiogram probe. B. Ultrasound gel used on the TEE probe. C. Patient's skin normal microbiota. D. Operating room. E. ICU nursing staff. F. Surgeon and/ or anesthesiologist.

B. Ultrasound gel used on the TEE probe.

A fomite is A. anything that is involved in pathogen transmission. B. a non-living object that can be the source of infection. C. an insect that transmits disease. D. an animal that transmits a disease through a bite. E. a child that doesn't practice good hygiene.

B. a non-living object that can be the source of infection.

Hand washing is an effective way to prevent A. airborne transmission of the disease. B. horizontal transmission of a disease. C. both vertical and horizontal transmission of a disease. D. either vertical or horizontal transmission of a disease. E. vertical transmission of a disease.

B. horizontal transmission of a disease.

Which of the following refers to a descriptive epidemiological study? A. Designed to determine which potential risk factors are actually relevant in the spread of the disease. Can include cross-sectional, retrospective, and prospective studies B. Used to judge the cause-and-effect relationship of risk factors (or preventative factors) and the development of disease. Often compares a treatment with a placebo C. Collecting data that characterize the occurrence, from the time and place of the outbreak to the individuals infected

C. Collecting data that characterize the occurrence, from the time and place of the outbreak to the individuals infected

Which of the following diseases can potentially be eradicated and why? Select all the correct answers. (NOTE: Please change all question marks to checkmarks for correct answers or empty boxes for incorrect answers.) A. TB, because there is an effective vaccine B. TB, if everyone received appropriate antibiotics C. Polio and measles, because humans are the only host and reservoir D. Polio, because there are effective vaccines E. Measles, because there is an effective vaccine (MMRV) F. Tetanus, because it is a non-communicable disease

C. Polio and measles, because humans are the only host and reservoir D. Polio, because there are effective vaccines E. Measles, because there is an effective vaccine (MMRV) Explanation: Diseases for which there is a preventative vaccine, and for which humans are the only host, may potentially be eradicated (in this question, measles and polio).

What was the main outcome of this case? A. Patients undergoing cardiovascular surgery are no longer given TEEs during the procedure. B. Patients undergoing cardiovascular surgery are no longer allowed to have visitors post-surgery. C. The FDA recommends that single-use, sterile containers of ultrasound gel are used for TEEs. D. Ultrasound gel is no longer used to coat the probe used in the TEE procedure. E. The FDA recommends limiting use of the TEE probe to less than five hours during cardiovascular surgeries.

C. The FDA recommends that single-use, sterile containers of ultrasound gel are used for TEEs.

Refer to Clinical Case Study: Pseudomonas aeruginosa At what point did the ultrasound gel become contaminated with P. aeruginosa? A. During manufacture of the gel. B. When the multi-use container was opened. C. We do not know exactly. D. When the anesthesiologist inserted the TEE probe into the patient. E. During shipment of the gel to the hospital.

C. We do not know exactly.

Look to the C. aureus figure Which of the following have been recommended by the CDC to reduce the risk of C. auris transmission? (NOTE: Please change all question marks to checkmarks for correct answers or empty boxes for incorrect answers.) A. Giving all patients in healthcare facilities prophylactic antibiotics. B. Cleaning the patients daily with disinfectant. C. Stopping transfer of any infected patient to another facility. D. Isolating an infected patient E. Cleaning patient's rooms with disinfectants on a daily basis. F. Notifying facilities to which a patient with C. auris may be transferred.

D. Isolating an infected patient E. Cleaning patient's rooms with disinfectants on a daily basis. F. Notifying facilities to which a patient with C. auris may be transferred.

Which of the following statements about pathogenesis is FALSE? A. Some intestinal pathogens rely on M cells to transport them across the intestinal mucosal membrane. B. Some pathogens produce siderophores to scavenge (sequester) iron. C. Some pathogens use pili to attach to eukaryote cells. D. Pathogens that destroy complement component C3b can avoid the classical pathway of activation. E. Type III secretion systems allow bacteria to inject molecules directly into a host cell.

D. Pathogens that destroy complement component C3b can avoid the classical pathway of activation.

Some people consider Staphylococcus aureus to be a primary pathogen, while others classify it as an opportunist. Which of the following statements supports the opinion that it is an opportunist? A. Outbreaks in groups of people such as football players have been reported. B. S. aureus is frequently resistant to methicillin. C. Only some strains of S. aureus produce toxins. D. S. aureus is found in the nasal passages of many healthy people. E. Antibiotic-resistant strains of S. aureus are increasingly being reported.

D. S. aureus is found in the nasal passages of many healthy people.

Look to the C. aureus figure What was the total number of people in the U.S. colonized with C. auris at the time this report was written? A. 45 B. 124 C. 2 D. 77 E. 122

E. 122 Explanation: Correct. 77 patients were infected and 45 close contacts were colonized.

Look to the C. aureus figure Why do you think the CDC recommends cleaning patient's rooms with a disinfectant effective against Clostridium difficile endospores in facilities where C. auris is found? A. All of these are probably reasons that the CDC recommends disinfectant that destroy bacterial spores. B. C. auris is highly resistant to heat, salt, and all disinfectants except those that are used to destroy Clostridium difficile. C. Patients with C. auris infections always have C. difficile infections as well, because the yeast infection suppresses their immune systems; C. difficile spores must be destroyed. D. If a facility has C. auris, it is also most likely contaminated with C. difficile because these organisms are genetically related and always occur together. E. Endospores are highly resistant, killed only by extreme heat or chemical treatment. A disinfectant that destroys spores will likely kill any other organisms as well.

E. Endospores are highly resistant, killed only by extreme heat or chemical treatment. A disinfectant that destroys spores will likely kill any other organisms as well.

Refer to comphrension: ignaz semmelweis & disinfection What was the control in Semmelweis's experiment? A. Women who delived their babies at home rather than in the hospital maternity ward. B. Women who delivered their babies in the hospital maternity ward rather than at home. C. Women who gave birth in the cadaver dissection room. D. Women who were assisted in childbirth by physicians and medical students rather than midwives. E. Physicians and medical students who delivered babies without washing their hands first.

E. Physicians and medical students who delivered babies without washing their hands first.

In which way does cytomegalovirus avoid the cellular immune response? A. Producing fake MHC class II molecules that NK & TC cells do not recognize B. Blocking the movement of virus antigens to the MHC class I molecule C. Inhibiting proteins such as p53 and preventing apoptosis D. Rapidly changing its surface antigens E. Encoding proteins that shut down the interferon genes F. Producing fake MHC class I molecules that NK and TC cells do not recognize

F. Producing fake MHC class I molecules that NK and TC cells do not recognize Explanation: CMV makes fake MHC class I molecules, tricking the immune system into missing the infected cell.