Ch. 14 ~ Risk of infectious and Communicable diseases ((exam 3))

history of infectious diseases

- 19th century many people were killed in Europe, America, and much of the rest of the world by epidemics of infectious diseases - noted: the need to prevent and control epidemics of infectious diseases, such as cholera, typhus, and influenza - this lead to advances in purifying drinking water, waste control, foods, etc --> today: changes in health patterns in the world's developed countries reflect an increased lifespan and living with chronic diseases / CVD/ Cancer

in 2015, WHO / more than 54% of 56.4 million deaths worldwide were due to what?

- ischemic heart - stroke - lower respiratory - COPD - Lung cancer - Diabetes - Dementia / alzheimers - diarrheal diseases - tuberculosis - road injuries

top 10 causes of death worldwide

- ischemic heart disease - stroke - lower resp infections - COPD - lung cancer - diabetes - alzheimer disease - diarrheal disease - TB - road injuries

New and reemerging infectious diseases

1- Toxic shock syndrome 2- Legionnaires disease 3- AIDs / HIV 4- lyme disease 5- Hantavirus pulmonary syndrome (HPS) 6- Escherichia coli 7- Group A strep 8- mad cow disease (bovine spongiform encephalopathy) 9- Ebola 10- zoonotic Ebola 11- Severe acute respiratory syndrome 12- bird flu 13- H1N1 influenza 14- Avian influenza 15- coronavirus 16- Zika virus

steps of an outbreak investigation

1. Interview 2. Collect data (how many sick/healthy, what time) 3. Develop treatment plan 4. Find source 5. Stop the spread Establish and verify diagnosis of reported cases; identify agent. Search for additional cases; collect critical data and specimens. Characterize cases by person, place, and time. Formulate and test tentative hypotheses regarding possible causative factors. Implement control measures to control the outbreak. Evaluate efficacy of control measures. Communicate findings; prepare written report

foodborne diseases

: involves biologic and nonbiologic agents and microorganisms and their toxins, marine organisms, and their toxins, fungi, and chemical contaminants Raw and undercooked foods/animal sources Domestic acquired foodborne pathogens. CDC 48 million people yr. get sick, 128,000 are hospitalized and 3,000 die --> monitored through the CDC FoodNet include infections caused by bacteria: Campylobacter, Listeria, Salmonella, Shiga toxin-producing Escherichia coli (STEC) 0157, shigella, vibrio, yersinia, cyclospora.

Campylobacterosis

A gastrointestinal condition characterized by diarrhea, abdominal cramps, and fever, caused by eating raw meat or unpasteurized milk contaminated with Campylobacter jejuni, a bacterium that infects poultry, cattle, and sheep. Campylobacteriosis is a leading cause of foodborne illness in the United States, and was not nationally notifiable until 2015. It also is an important cause of diarrheal illness throughout the world regardless of people's age. It is often implicated in traveler's diarrhea. The annual median number of Campylobacter outbreaks had increased in the United States from 28 in 2004-2006 to 56 in 2010-2012. Antimicrobial susceptibility testing of isolates from 4,793 domestic and 1,070 travel-associated infections revealed that, comparing 2004-2009 to 2010-2012, ciprofloxacin resistance increased among domestic infections

attack rates

As data are collected on individual cases in an outbreak investigation, attack rates can be calculated according to demographic variables such as age, sex, and other factors or attributes like occupation or exposure to the suspected agent. These data are helpful in comparing the characteristics of those who develop the infection with the characteristics of those who do not when conducting case-control studies. This occurs when epidemiologists test tentative hypotheses to explain the outbreak and identify the population at risk

carriers

Asymptomatic persons or animals that harbor in their bodies pathogens that can be transferred to others.

surveillance at the federal level

At the U.S. federal level, the CDC maintains surveillance systems to analyze data for disease trends and outbreaks. For example, one such surveillance system is FoodNet (Foodborne Disease Active Surveillance Network), which is a collaborative effort among the FDA, the U.S. Department of Agriculture, and the CDC. Specific states, which report cases and outbreaks of foodborne illnesses, are selected to participate in the CDC Emerging Infections Program

treatment for gonorrhea

People who have had gonorrhea and have been treated can get the disease again if they have sexual contact with people infected with gonorrhea. Every person who has been diagnosed and treated for gonorrhea should notify all recent sex partners so that they can see a healthcare provider and be treated. This will reduce the development of serious complications from gonorrhea and also reduce the possibility of reinfection. All people involved must avoid sex until they have completed their treatment of gonorrhea.

chlamydia is?

Chlamydia is known as a "silent" infection because most infected people are asymptomatic and lack abnormal physical examination findings. In women, the bacteria initially infect the cervix, where the infection may cause signs and symptoms of cervicitis (e.g., mucopurulent endocervical discharge, easily induced endocervical bleeding), and sometimes the urethra, which may result in signs and symptoms of urethritis (e.g., pyuria, dysuria, urinary frequency). Infection can spread from the cervix to the upper reproductive tract (i.e., uterus, fallopian tubes), causing pelvic inflammatory disease (PID), which may be asymptomatic and is a major cause of infertility among women of childbearing age. A pregnant woman may pass chlamydial infection to her newborn during delivery, resulting in subsequent neonatal eye infection or pneumonia. Men who are symptomatic typically have urethritis, with a mucoid or watery urethral discharge and dysuria. A minority of infected men develop epididymitis (with or without symptomatic urethritis), presenting with unilateral testicular pain, tenderness, and swelling

chlamydia

Chlamydia, caused by infection with Chlamydia trachomatis, is the most common notifiable disease in the United States. It is among the most prevalent of all STDs, and since 1994, has comprised the largest proportion of all STDs reported to the CDC, with 1,526,658 cases reported in 2015 at a rate of 478.8 per 100,000 population. Studies also demonstrate the high prevalence of chlamydial infections in the general U.S. population, particularly among young women. The rate of reported cases of chlamydia is highest among adolescents and young adults aged 15 to 24 years. In 2015, the rate of reported cases of chlamydia among 15- to 19-year-olds was 1,857.8 cases per 100,000 population and the rate among 20- to 24-year-olds was 2,574.9 cases per 100,000 population. From 2011 to 2013, the rate of reported cases decreased to 443.5 cases per 100,000 population. The rate of reported cases then increased in 2014 at 452.2 and up 5.9% again in 2015 at 478.8

condoms lubricated with ____ are most effective

Condoms lubricated with spermicides (especially nonoxynol-9 or N-9) are no more effective than other lubricated condoms in protecting against the transmission of STDs. Based on the findings from several research studies, N-9 may itself cause genital lesions, providing a point of entry for HIV and other STDs. Therefore, since 2010, the CDC has recommended that N-9 not be used as a microbicide or lubricant during vaginal or anal intercourse since 2010), and remains in its updated 2015 guidelines

how do you get campylobacter?

Consumption of contaminated poultry is the most common source of Campylobacter infection, although undercooked meats, ground beef, pork, cheese, eggs, shellfish, unpasteurized milk, and direct exposure to pets and farm animals have been implicated. Generally, the incubation period ranges from 2 to 5 days. The resulting diarrheal illness usually lasts no more than a week. Typical symptoms include nausea, vomiting, abdominal pain, fever, headache, and muscle pain. Occasionally, a severe case may last longer, and about 25% of the people affected may experience a relapse. Campylobacter infection is usually a self-limited illness, diagnosed by stool culture, and treated by antidiarrheal medications such as loperamide. In more severe cases, antibiotics are prescribed. It is essential that affected people drink plenty of fluids, such as oral rehydration solutions, and wash hands carefully to prevent transmission to others

zoonoses

Diseases transmitted from animals to humans --> hantavirus and monkeypox

endemic vs epidemic

Endemic: the disease is constantly present in the region (usual prevalence) Epidemic: greater that normal occurrence of a disease in a region *Pandemic: happening across the world An endemic disease, infection, or infectious agent occurs when it becomes prevalent within a population or geographic area. For example, chloroquine-resistant malaria is endemic in most of Africa, the Middle East, Asia, and all of the South Pacific islands (CDC, The yellow book 2017). An epidemic refers to a significant increase in an infection or infectious disease beyond the expected (endemic) level in a certain population and/or geographic area.

Two criteria must be met for an event to be defined as a water-associated disease outbreak

First, two or more people must be linked epidemiologically by time, location of exposure to water, and illness characteristics. Second, the epidemiologic evidence must implicate recreational water or volatilization of water-associated compounds into the air surrounding the water as the probable source of illness. Multiple etiologic agents should be considered when waterborne disease is suspected and might be related to sewage or septic contamination (CDC, 2015a). The CDC has distributed guidance for assisting state and local health departments, aquatic facility inspection programs, building officials, the aquatics industry, and other interested parties in improving the health and safety at public aquatic facilities

escherichia coli 0157 :H7

Toxin-producing strain of E. coli First seen in 1982 Leading cause of diarrhea worldwide Shiga toxin-producing Escherichia coli O157 is a deadly form of E. coli, which produces symptoms of severe abdominal cramps, bloody and nonbloody diarrhea, and vomiting that generally resolve within 7 to 10 days. In the very young and the elderly, infection with STEC O157:H7 can cause fatal hemolytic-uremic syndrome and renal failure (CDC, E. coli). This severe complication includes temporary anemia, profuse bleeding, and kidney failure.

at least ____ people lack access to adequate sanitation and use of drinking water

Globally, at least 2 billion people lack access to adequate sanitation and use a drinking water source contaminated with feces. Diarrheal diseases such as cholera kill more children than AIDS, malaria, and measles combined, making it the second leading cause of death among children less than 5 years of age. The majority of these deaths are attributable to unsafe water, poor sanitation, and inadequate hygiene

hospitalization for salmonella

However, in some cases, the diarrhea may be so severe that the patient needs to be hospitalized. Each year, 19,000 hospitalizations and 380 deaths from salmonellosis occur in the United States. A small number of persons with Salmonella develop pain in their joints. This is called reactive arthritis, and it can last for months or years. It also can lead to chronic arthritis which is difficult to treat. Treatment of dehydration and electrolyte imbalance is essential. Antibiotics are not usually necessary unless the infection spreads from the intestines. The CDC has identified Salmonella bacteria that have become resistant to antibiotics, largely as a result of the use of antibiotics to promote the growth of food animals

patients infected with N. Gonorrhoeae

Patients infected with N. gonorrhoeae frequently are coinfected with C. trachomatis. Therefore, patients with gonorrhea should be tested for other STDs. Because of findings that chlamydial and gonorrheal infections often coexist led to the recommendation that patients treated for gonococcal infection also be treated routinely with a regimen that is effective against uncomplicated genital C. trachomatis infection. In addition, because most gonococci in the United States are susceptible to doxycycline and azithromycin, routine co-treatment hinder the development of antimicrobial-resistant N. gonorrhoeae

healthy people 2020 environmental objectives related to water quality

Increase the proportion of persons served by community water systems who receive a supply of drinking water that meets the regulations of the Safe Drinking Water Act. Reduce waterborne-disease outbreaks arising from water intended for drinking among persons served by community water systems. Reduce per capita domestic water use. Maintain the percentage of days that beaches are open and safe for swimming. Reduce the global burden of disease due to poor water quality, sanitation, and insufficient hygiene.

indirect contact

Indirect contact involves contact of a susceptible host with a contaminated intermediate inanimate object, called a vehicle, such as a contaminated surgical instrument, needle, toy, soiled clothing, or bed linen. Vehicles also include food, water, and contaminated hands that are not washed (Heymann, 2014). Indirect contact also includes vector transmission. Vectors are animal or insect carriers of infectious agents. Mechanical vector-borne transmission occurs when an insect carries the microorganisms on its feet or proboscis, or through its gastrointestinal tract

Listeria monocytogenes

Listeriosis Listeria monocytogenes can cause listeriosis, an uncommon but potentially fatal foodborne bacterial disease. The disease primarily affects older adults, pregnant women, newborns, and adults with weakened immune systems, and can result in miscarriage, stillbirth, or severe illness and death in newborn infants. However, rarely, persons without these risk factors can also be affected. The risk may be reduced by recommendations for safe food preparation, consumption, and storage

why id chlamydia underdiagnosed?

Like chlamydia, gonorrhea is substantially underdiagnosed and underreported; the number of reported cases is suspected to underestimate incidence by approximately 50%. In 2009, the gonorrhea rate decreased to 98.1 cases per 100,000 population. This was the lowest rate since recording of gonorrhea rates began in the 1970s. Between 2009 and 2012, the rate increased slightly each year to 106.7 cases per 100,000 population in 2012. In 2013, the rate decreased slightly to 105.3 cases per 100,000 population and then during 2013-2015, the rate increased each year. By 2015, a total of 395,216 cases were reported for a rate of 123.9 cases per 100,000 population. The rate of reported gonorrhea cases among males was higher than the rate among females. Reported gonorrhea cases continued to be highest among adolescents and young adults, with persons aged 15 to 44 years accounting for 92.7% of reported gonorrhea cases in 2015 (CDC, Gonorrhea). These data indicate that the rate of gonorrhea still remained higher in 2015 than the Healthy People 2020 target of 251.9 new cases of gonorrhea among females aged 15 to 44 years per 100,000 population, and 194.8 new cases of gonorrhea among males aged 15 to 44 years per 100,000 population

nontyphoid salmonella

Nontyphoid Salmonella is a bacterial disease transmitted by contaminated food and water, or contact with infected animals and reptiles. Because many milder cases are not diagnosed or reported, the actual number of infections may be 30 times greater. There are many kinds of Salmonella bacteria. Salmonella serotypes Typhimurium and Enteritidis are the most common in the United States. People at risk for severe or complicated illness include infants, the elderly, people with compromised immune systems, and organ transplant recipients. Salmonellosis is characterized by diarrhea, fever, and abdominal cramps 12 to 72 hours following exposure, and generally lasts 4 to 7 days. The majority of those infected recover without treatment

reservoir

location where an infectious agent is normally found, where it lives and reproduces under normal circumstances.

healthy people 2020 objectives for STDs

Reduce the proportion of females aged 15 to 44 years who have ever required treatment of pelvic inflammatory disease (PID). Reduce congenital syphilis. Reduce the proportion of adolescents and young adults with Chlamydia trachomatis infections. Reduce gonorrhea rates. Reduce sustained domestic transmission of primary and secondary syphilis. Reduce the proportion of adults with genital herpes infection due to herpes simplex type 2. Reduce the proportion of females with human papillomavirus (HPV) infection. Increase the proportion of sexually active females aged 24 years and younger enrolled in commercial health insurance plans who are screened annually for genital Chlamydia infections. Increase the proportion of sexually active females aged 24 years and younger enrolled in Medicaid who are screened annually for genital Chlamydia infections. Increase the proportion of HIV-infected persons who know they are infected.

screenings for STDs/ STIs

Screening programs have been demonstrated to reduce rates of adverse sequelae in women. There are a number of diagnostic tests for chlamydia, including cell culture (the criterion standard) and nucleic acid amplification tests (NAATs), and others. NAATs are the most sensitive tests and can be performed on easily obtainable specimens such as vaginal swabs (either clinician- or patient-collected) or urine (CDC, Chlamydia fact sheet, 2018). Urine is the specimen of choice for males. Self-collected vaginal swab specimens perform at least as well as other approved specimens using NAATs. Generally, girls in adolescent phase of development may collect their own urine or swab their own vagina to screen for Chlamydia especially if they are not having symptoms. Persons with chlamydia should abstain from sexual activity for 7 days after single-dose antibiotics or until completion of a 7-day course of antibiotics, to prevent spreading the infection to partners. Chlamydia can be easily cured with antibiotics. HIV-positive persons with chlamydia should receive the same treatment as those who are HIV-negative

outbreaks of escherichia coli 0157

Several outbreaks of E. coli O157:H7 have been associated with commercially packaged foods and fresh produce (CDC, Multistate Foodborne Outbreak Investigations). A recent multistate outbreak of E. coli O157:H7 involved I. M. Healthy Brand Soy Nut Butter products (CDC, 2017c). See Chapter 15 for a further discussion of E. coli O157:H7. Foodborne infections should be considered in people with diarrheal illness who are residents of, or travelers to an area where foodborne outbreaks have been reported. A careful history also should consist of contact with animals and reptiles as a source of infection.

racial/ethnic disparities in chlamydial infection

Substantial racial/ethnic disparities in chlamydial infection exist, with prevalence among non-Hispanic blacks approximately 5.9 times the prevalence among non-Hispanic whites. Chlamydia is also common among men who have sex with men (MSM) (CDC, Chlamydia fact sheet). Chlamydia is a nationally notifiable disease, and CDC 2016 data indicated that the Healthy People 2020 objective to reduce C. trachomatis infections among females 15 to 24 years of age attending family planning clinics to 6.7% had been met (CDC, 2017). Chlamydial infection is caused by a bacterium, C. trachomatis, which is transmitted during vaginal, oral, or anal sexual contact with an infected partner.

descriptive epidemiology

The aspect of epidemiology concerned with organizing and summarizing health-related data according to time, place, and person --> By becoming familiar with the data it is possible to learn what information is reliable and informative. the same unusual exposure reported by many of the people affected and what may not be as reliable.

where is waterborne diseases not present?

US, Canada, UK, and Europe. The United States has one of the safest public water supplies in the world. The year 2008 marked the 100th anniversary of one of the most significant public health advances in U.S. history, the disinfection of drinking water. However, millions of people worldwide do not have access to safe water. In 2015, 71% of the global population used a safely managed drinking-water service.

USDHHS

United States Department of Health and Human Services --> protects the nation's health by developing guidelines that promote health and quality of life by preventing and controlling disease, injury, and disability

what is the most deadly disease?

lower respiratory infections, it causes 3.2 million deaths worldwide

to establish that an outbreak exists, what must happen?

a comparison of the current incidence of cases with baseline or endemic status is essential

surveillance

a continua dynamic method for gathering data about the health of the general public for the purpose of primary prevention of illness

droplet transmission

a form of contact transmission, the mechanism of transfer of the pathogen to the host is quite distinct from either direct or indirect transmission. --> because of this, droplet transmission is considered a separate route of transmission. --> droplets are generated from the source person primarily during coughing, sneezing, and talking, and are propelled a short distance through the air and deposited on the conjunctivae, nasal mucosa, or mouth of another person

epidemic curve

a graphic display of the cases of disease according to the time or date of onset of symptoms --> helps to determine the incubation period of the infection and if the problem is ongoing --> as a general rule, a unit of time used in an outbreak investigation is one-fourth (0.25) of the average incubation period for the illness under investigation

carrier

a person or animal that harbors an infectious organism and transmits the organism to others, although having no symptoms of the disease

invasiveness

ability of the agent to destroy body cells

pathogenicity

ability of the agent to produce an infectious disease in a susceptible host

immunogenicity

ability of the agent to produce specific immunity within the host

toxicity

ability of the agent to produce toxins

WHO statistics

aging populations - globally noncommunicable disease/cancer and cardiovascular disease will increaae and deaths occur - HIV / AIDS no longer in the top 10 causes of death, remains significant and projected to drop - new pathogenic organisms have emerged - new strains of known organisms have emerged and more virulent and resistant to many antibiotics - infectious diseases have emerged as a form of terrorism - infectious disease characteristics have changed but is still a significant burden in most of the world - despite the advances during the 20TH century in prevention and control of infectious diseases - advances occurred mainly in developing countries

syphilis

an STD that attacks many parts of the body and is caused by a small bacterium called a spirochete Syphilis has often been called "the great imitator," because many of the signs and symptoms are indistinguishable from those of other diseases. This genital ulcerative disease is caused by the bacterium Treponema pallidum. It is transmitted from person to person through direct contact with a syphilitic sore. These sores occur mainly on the external genitals, vagina, anus, or in the rectum, although they can occur on the lips or in the mouth. Transmission occurs during vaginal, anal, or oral sex, and the organism can pass the placental barrier and infect the fetus.

Pandemic

an epidemic that generally spreads worldwide.

common course outbreak

an outbreak characterized by exposure to a common, harmful substance

common source outbreak

an outbreak characterized by exposure to a common, harmful substance --> the same origin! same person or vehicle as the reservoir or means of transmission

antibiotics for chlamydia

azithromycin or doxycycline or erythromycin

STDs/ STIs caused by bacteria

can be treated and usually cured with antibiotics, but those caused by viruses cannot be cured this way. All partners must be notified so that they can be examined and treated, if necessary. Other than abstinence, a long-term mutually monogamous relationship with a partner who has been tested and is known to be uninfected is the best way to avoid STDs. Sexual partners should talk to each other about their STDs so that preventive action can be taken. Prevention of STD transmission does not include washing the genitals, urinating, and/or douching after sex. Latex condoms can reduce the risk of transmission but only when used consistently (every time) and correctly. However, genital ulcer diseases, such as syphilis, can occur anywhere within the male and female genital areas, whether or not they are covered by a latex condom

virulence

severity of the infectious disease that results from exposure to the agent

epidemic

significant increase in the number of new cases of a disease that past experience would have predicted for that place, time, or population, an increase in incidence beyond that which is expected

contagious

communicable by direct or indirect contact

surveillance for infectious and / or communicable diseases

consists of a variety of efforts at both the state and federal levels.

recreational water outbreaks

contaminated ponds, lakes, streams, swimming pools Most recreational water outbreaks have been associated with treated water venues such as swimming pools or spas. Box 14.5 presents selected Healthy People 2020 objectives for environmental health and water quality

T or F: federal regulatory agencies have authority over treated recreational water

false. none do. The Environmental Protection Agency (EPA) sets water quality guidelines for natural, untreated recreational water (e.g., lakes, rivers, and oceans). Despite drinking water treatment advances, it is estimated that millions of annual diarrheal illness episodes still occur in the United States from exposure to contaminated municipal drinking water. In addition, we face emerging public health concerns such as chlorine-tolerant pathogens and the increasing complexity of waterborne diseases.

infectious disease may or may not be contagious or communicable

for a disease to be communicable, or contagious, there must be an epidemiologic triad plus a chain of infection

____ is second to chlamydia in number of cases.

gonorrhea In 2015, persons aged 15 to 44 years accounted for 92.7% of reported gonorrhea cases with known age (CDC, Gonorrhea). Infections with Neisseria gonorrhoeae, like those resulting from C. trachomatis, cause several clinical syndromes, including urogenital, pharyngeal, and rectal infections in males and females, and conjunctivitis in adults and neonates. If untreated, gonorrhea can cause PID, tubal infertility, ectopic pregnancy, and chronic pelvic pain

surveillance at the state level

healthcare providers and healthcare facilities are required to report certain infectious diseases to state health departments. --> state public health departments that monitor disease incidence and identify possible outbreaks within their states report these data to the CDC.

pathogenicity

in addition to the interaction between the infectious agent, the host, and the environment, the progression of an infectious agent depends on the pathogenicity. --> this is the ability of an infectious agent to cause disease in a susceptible host. --> it depends on the infectivity of the infectious agent, its ability to invade and destroy body cells (invasiveness), produce toxins (toxicity), and its virulence

host

in infectious disease epidemiology, just the presence of an infectious agent is not sufficient to produce an infectious disease --> the process requires a susceptible host. There are several host factors that determine whether a person is at risk for an infection or an infectious disease. --> this includes age, sex, race, physical and emotional health, and immune status

drug-resistant strains of gonorrhea

increasing in many areas of the world, including the United States, making successful treatment of gonorrhea more difficult. Antimicrobial susceptibility patterns of N. gonorrhoeae have been closely monitored since 1986 through the Gonococcal Isolate Surveillance Project (GISP), and the information has been used to update treatment recommendations. The increased prevalence of fluoroquinolone resistance in N. gonorrhoeae became widespread in the United States in the 1990s and 2000s, when the proportion of N. gonorrhoeae isolates in MSM that were resistant to ciprofloxacin (a fluoroquinolone antimicrobial) increased significantly. While the first fluoroquinolone-resistant N. gonorrhoeae cases were detected among heterosexuals, fluoroquinolone resistance became widespread in the continental United States among MSM with gonorrhea before becoming widespread among heterosexuals. By 2011, the CDC no longer recommended the use of fluoroquinolones for the treatment of gonococcal infections and associated conditions such as PID.

the time between exposure to an infectious agent and the manifestation of symptoms in the host

incubation period

secondary infection

infections that occur within the accepted incubation period following exposure to a primary case

chain of infection

infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, susceptible host

agent

infectious agents are biological in nature and are capable of producing an infection or infectious disease and include bacteria, viruses, rickettsiae, fungi, protozoa, and helminths

portals of entry and exit

infectious agents both enter and leave the body in multiple ways. Portals include the skin, respiratory tract, alimentary tract, genital tract, conjunctiva, and vertical transmission from parent to offspring.

____ and ____ are in the top 10 causes of death in the US in 2015

influenza and pneumonia

toxic shock syndrome

killed several women before it was linked to the use of high-absorbency tampons that provided a moist, warm home where the bacteria could thrive. --> it was also found to be associated with the contraceptive sponge and diaphragm birth control methods

aging populations

middle and low-income countries/next 20 years deaths will be due to non-communicable diseases will rise significantly

airborne transmission

occurs through contact with contaminated respiratory droplets spread by a cough or sneeze --> when microorganisms are carried in the air in small particles, called droplet nuclei, at distances that exceed a few feet. --> ex: TB bacteria into the air when he or she coughs, sneezes, speaks, or sings. people nearby breathe this in --> can also happen when spores spread by airborne transmission through dust when they are mixed in with dry soil

biologic vector-borne transmission

occurs when propagation of the microorganism is required within the insect before it can be transmitted to another host. malaria!

propagated (continuous) outbreak

one in which the infection is transmitted from person to person over a longer period of time than with a common source outbreak, and it can generate secondary infections with intervals between peaks that approximate the usually incubation period for the infection

healthcare-associated infection

originating in a healthcare facility; formerly called nosocomial infection

propagated outbreak

outbreak resulting from direct or indirect transmission of an infectious agent from an infected person to a susceptible host; secondary infections can occur

infectious disease

presence and replication of an infectious agent in the tissues of a host, with manifestation of signs and symptoms. An infectious disease need not be contagious or communicable

advances made in 3rd world countries to prevent and control infectious diseases

purified drinking water, waste control, plentiful foods, immunizations, and drug therapy

Legionnaire's disease

severe, often fatal bacterial infection characterized by pneumonia and liver and kidney damage Legionnaires' disease was first recognized among hotel guests during an outbreak in Philadelphia, PA, in 1976. Between 8,000 and 18,000 people are hospitalized with Legionnaires disease in the United States each year. However, many infections are not diagnosed or reported, so this number may be higher. More illness is usually found in the summer and early fall, but it can happen any time of year. Outbreaks of this disease have been associated with potable water sources, air-conditioning cooling towers, and cruise ships. Legionella bacteria are not transmitted from person to person

the CDC recommends dual therapy with ___ and __ to treat gonorrhea

the CDC recommends dual therapy with ceftriaxone (an injectable cephalosporin) 250 mg intramuscularly as a single dose plus azithromycin 1 g orally as a single dose given together for 7 days as the most effective treatment for uncomplicated gonorrhea. However, in the case of azithromycin allergy, doxycycline (100 mg orally twice a day for 7 days) can be used in place of azithromycin as an alternative second antimicrobial when used in combination with ceftriaxone (or cefixime)

endemic

the constant or usually prevalence of a specific disease or infectious agent within a population or geographic area

colonization

the presence and multiplication of infectious organisms without invading or causing damage to tissue

germ theory of disease

the principle that microorganisms cause disease idea that infectious diseases are caused by microorganisms --> specific organisms cause specific diseases

reservoirs

the third component in the epidemiologic triad. this provides reservoirs of infectious agents. These can be humans, animals, plants, insects, water, and soil.

transmission

the transfer of an infectious agent from one person or place to another

secondary infections

those that occur within the accepted incubation period following exposure to a primary case.

direct contact occurs when?

through direct body surface-to-body surface contact and physical transfer of microorganisms between a susceptible host and an infected or colonized person (or animal)

incubation period

time period between initial contact with the infectious agent and the appearance of the first signs or symptoms of the disease •multiplication period and infection occurs (exposure to signs and symptoms). Influenza 24-72 hrs after virus enters. Communicable one day prior to symptoms and 3-7 days after symptoms start

goals and objectives for prevention and control of infectious diseases are designed to do what?

to reduce morbidity, mortality, and costs associated with infectious diseases

infectivity

varies depending on the route of entry of the infectious agent and the susceptibility of the host.

colonization

when an infectious agent is present and there are no clinical signs of disease. colonization with the infectious agent is said to have occurred, and the infected person is capable of transmitting the agent.

Noroviruses

•"Norwalk-like viruses" •Gastroenteritis •Fecal-oral route of transmission •Nausea, vomiting, and diarrhea with cramps •Primarily affects adults •Epidemic outbreaks in schools and cruise ships •Campylobacter infection: bacteria; leading cause, contaminated poultry •Listeria monocytogenes: bacteria; safe food prep, consumption, storage •Nontyphoid Salmonella: bacteria; 4-7 days (diarrhea, fever, abdominal pain) •Escherichia coli O157:H7: deadly fatal hemolytic-uremic syndrome (anemia, profuse bleeding and renal failure) --? stomach flu! most common cause of acute infectious gastroenteritis in people of all ages, and are the leading cause of disease outbreaks from contaminated food in the US --> spread from one infected person to another by fecal-oral route.

outbreak investigation

•Establishing the existence of an outbreak: comparison of the incidence of cases with baseline. Observed rates must be greater than the expected level ie.) Smallpox eradicated worldwide in 1977 so 2 cases in U.S. are above the expected level •Describing cases by person, place, and time: demographic variables such as age, sex, occupation, exposure used to compare the characteristics of those who develop an infection to those who do not •Common source outbreak: same origin (same person or vehicle as the reservoir or means of transmission) •Propagated (continuous) outbreak: infection transmitted from person to person over a longer period of time than a common source ie.) measles •Secondary infections: infection occurring during or after treatment for another infection

influences of emerging and reemerging inf ectious diseases

•Microbial adaptation and change •Human susceptibility to infection •Climate, changing ecosystems, and human behavior •Travel, technology, and industry •Lack of political will and breakdown of public health infrastructure •Outbreaks of emerging and reemerging infections influence/ disrupt economic activity and development

waterborne diseases

•Normally safe drinking water in U.S., Canada, UK, and most of Europe •884 million people lack basic-drinking-water service •159 million people dependent on surface water •Globally, 2 billion people lack access to adequate sanitation and use a drinking water source contaminated with feces •Cholera/ diarrheal disease 2nd leading cause of death in children < 5yr •Drinking water outbreaks: associated with Legionella in plumbing systems and untreated groundwater •Recreational water outbreaks: chemical or infectious pathogen exposure (hot tubs, pools, spas), untreated lakes and oceans •2008 marked 100 years of disinfecting water in the U.S.

healthcare-associated infections (HAIs)

•Previously known as nosocomial infections •Significant morbidity and mortality: estimated one in every 20 inpatients has an infection related to healthcare •Costly: $billions •Loss of tens of thousands of lives •Cost of emotional, financial and medical consequences •UTI's (catheter associated), SSI's (surgical site), bloodstream infections (central lines), and pneumonia •1-3 million HAIs in long-term care

STDs and STIs

•STDs among leading cause of morbidity and mortality in the U.S. Affect men and women, all backgrounds and economic levels. •CDC reports one-third of new HIV cases were heterosexually acquired. •Actual rate of infection may be twice the reported rate/ d/t undiagnosed or untreated. Annual Surveillance Report captures only a fraction of the true burden •Undetected d/t no symptoms, long-term health consequences (women) •New cases: 15-24 yo •$16 billion direct medical cost •Chlamydia, Gonorrhea, Syphilis, Trichomoniasis, Human Papillomavirus (HPV) •Human Immunodeficiency Virus (HIV •Herpes Simplex Virus •Hepatitis viruses

epidemiologic triad

•What: agent, microbe that causes the disease •Who: host, human or animal, or insect harboring the the infectious agent •Where: environment, external factors allowing the transmission

chain of infection includes?

•a portal of exit from the infected person (or animal) •a means of transmission •a portal of entry to a susceptible host