Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
36 Cards in this Set
- Front
- Back
|
Epidemiology
|
Branch of medical science dealing with TRANSMISSION and CONTROL of disease
Examines DISTRIBUTION and DETERMINANTS of disease frequency in human pops. |
|
|
Patient Zero
Reportable disease |
First person to have the disease, also the INDEX CASE
Must be reported due to severity, transmissibility, must notify CDC and WHO |
|
|
How did John Snow "found" epidemiology?
|
Tracked down cholera in 1850s to pump on Broad street, removing pump hundle stopped disease.
|
|
|
5 core terms of epidemiology
|
Endemic = always present in low frequency
Epidemic = High frequency over short time (Flu) Pandemic = Epidemic occurs over wide geographic area (HIV/AIDS) Incidence = number, Prevalence = proportion |
|
|
Give examples of how technology spreads disease (4)
|
Travel by jet, use of blood banks (Hep C), suburban sprawl (lyme disease, ticks), factory farming (mad cow disease, influenza in Asian poultry, e.coli)
|
|
|
Define Reservoir, give 3 examples
Name 3 diseases, their causative agents, infection sources, and reservoirs. |
Where disease agent is found, origin of new cases. Soil/water, Other organisms, Humans.
Cholera - Vibrio cholarae - Fecal contamination - Humans (gut)/H2O Botulism - Clostridium botulinum - soil, contaminated food - soil Anthrax - Baccillus anthracis - product from infected animals - livestock/soil |
|
|
What are 3 controls against reservoirs?
|
Eliminate animals if domestic (cows)
Wild animal - not so simple (bats, mosquitos) Human carrier - quarantine, immunize, treat. Very difficult. |
|
|
Define: Zoonosis. Give an example
|
Disease primarly infects animals, occasionally transmitted to humans.
Person --> person transfer rare, usually animal --> person. Example: SARS |
|
|
Define: Carrier, give an example
|
Pathogen infected individual showing no signs/symptoms of disease. (could be in carrier state - colds/influenza spread this way).
Typhoid Mary. |
|
|
Name 4 ways to control against contamination
|
Water treatment (chlorination)
Food handling, prep laws Food masks limits URespiratory pathogens (but hard to institiute) Hand washing = ultra effective |
|
|
Name 7 causes for emerging/reemerging infectious disease
|
Increasing population
Population movement (travel, migration) Changes in behavior (sex, drugs) Industrialization of agriculture Increased drug resistance among pathogens (due to antibiotics) Immunosuppressed individuals Disruption of public health systems (ex: war) |
|
|
What is key for epidemiology to succeed globally?
|
A multidisciplinary collaboration to detect, control, prevent disease. COOPERATION.
|
|
|
Define: direct transmission. Give two types.
Define: Indirect transmission. Give 3 types. Know general curve shape |
Direct: Host --> Host
physical contact (transfer via touch, body fluids, etc), airborne Indirect: Food and water, vector-borne, fomites |
|
|
If a pathogen is successful, it must....?
Give an example of this. |
Coevolve with the host. Cannot kill the host.
Myxomatosis virus to kill rabbit population, virulence went down after 95% of infected rabbits died. |
|
|
Disease ecology - 4 major factors. Explain how they relate to VIRULENCE.
|
Survivability of Pathogen
Mode of transmission Vector borne Evolutionary history (relate to myxomatosis). SVEM |
|
|
Define: herd immunity
Why does transmission threshold vary? |
Disease spread limited if percent immune above transmission threshold
Depends on how infectious agent is |
|
|
Current epidemics: AIDS
|
AIDS. First case reported 1981 in US. 1 million cases, 600K deaths. Can be managed with treatment, but very expensive. No cure/vaccine so transmission control essential.
|
|
|
Causes of AIDS
|
Men - male-male contact (LANGUAGE!)
Females - heterosexual contact Also important: Injection drug use. |
|
|
What are infections occurring during admission to healthcare facility? Incidence? 2 ways of being spread. Give 3 examples.
|
Nosocomial infections.
1.7 million, 100K deaths. Patient-patient cross infection, healthcare worker - patient S. Aureus spread via door knobs, railings. UTI due to catheter colonization. Surgical site infections due to open skin. |
|
|
Be familiar with reasons hospital leads to infectious disease spread (don't memorize)
|
Low immunity, patients =pathogen reservoirs, multiple patients per room, breached skin, newborns + very old, antibiotics = MDR pathogens, surgery, steroids.
|
|
|
Airborne disease. Is air a habitat? Which type of bacteria have advantage, why?
|
No, organisms cannot grow in it.
Gram +, can tolerate dessication, which is necessary during passage through air |
|
|
Compare outdoor and indoor air
|
Outdoor: Lower overall, more soil bacteria (spore formers), more molds
Indoor: Higher overall, human respiratory bacteria in air for hours - days. Breath in droplets, get disease in upper respiratory tract, possible elsewhere. |
|
|
Tuberculosis:
Bacteria, type of bacteria, contagious?, how deadly, symptoms |
Mycobacterium tuberculosis, gram +, highly contagious.
Most deadly single agent disease, 1.5 million deaths world wide. Fever, fatigue, weight loss, cough, bloody sputum. |
|
|
TB: 2 types of infection. How transmitted + treated?
|
Active and latent. Infects 1/3, 1/10 gets active, transmissible form. Isolate active, treat for 2 weeks, cease to be contagious.
|
|
|
Other TB facts to know (not emphasized)
|
Primary infection
Grow and survive in macrophage. Tubercules. Show up on Xray. May grow unchecked --> Primary pulmonary tuberculosis. Move throughout body --> miliary tuberculosis. SKIN TEST. Antibiotic treatment. Serial treatments + MDR. XDR. |
|
|
Streptococcus pyogenes
|
AIRBORNE BACTERIAL: GRAM +
Causes strep throat, scarlet fever, toxic shock, impetigo, "FLESH EATING". Strains (SEROTYPES) defined by M layer proteins Produce toxin that lyses red blood cells, and others. Can be a part of upper resp flora w/o problems, occasionally causing strep |
|
|
Streptococcus pneumonia
|
AIRBORNE BACTERIAL: GRAM +
Causes pneumonia. Capsule makes cells resistant to phagocytosis Invades lung tissue Serotypes (antigenic determinant) determined by capsular polysaccharides. Over 90 types - hard to make a drug. |
|
|
Bordella pertussis
|
Whooping cough in children. Spread via coughing, nasal drip. 7-14 days incubation. Binds to sulfatides on cilia, impairs escalator, coughing fit, spreads to next host.
|
|
|
Leprosy
|
Mycobacterium leprae. Organism grows in macrophage. Nodular lesions, pigment loss, thickened skin. EXTREMELY LONG incubation period, many infected as a child. Very small % show symptoms. Kills PERIPHERAL NERVES. Can be completely cured by antibiotics.
|
|
|
Respiratory viral disease facts (3)
|
Not easily controlled due to few drugs. Cause more infectious diseases than any other organisms. Usually not serious, problem in immunocompromised, elderly, young.
|
|
|
Measles
|
Rubeola virus, paramyxovirus (RNA).
Usually death due to COMORBIDITY. Highly infectious (600K deaths), but not in US due to MMR. Red eyes, fever, cough, rash for 7 days. But note secondary rise. |
|
|
Mumps
|
Mumps virus - paramyxovirus (RNA)
Spread via airborne droplets. Inflammation of salivary glands, neck swelling, encephalitis and sterility. Very rare in US (MMR) |
|
|
Rubella (German measles/3-day measles)
|
Rubella virus = Togavirus (RNA virus)
Resemble milder form of measles, less contagious. DANGEROUS TO FETUS - stillbirth, deafness, heart defects, brain damage. ery rare in US |
|
|
Chicken pox
|
Varicella virus. DNA herpesvirus.
Itchey rashes. Decline due to vaccine. Establishes lifelong latent infection in nervecells, can cause SHINGLES in elderly/immunosurpressed. Booster immunization to prevent shingles. |
|
|
Common cold
|
RHINOVIRUS, CORONAVIRUS
average = 3 colds/year |
|
|
Influenza
|
Orthomyxovirus. ssRNA.
Spike proteins - hemagglutinin, neuraminidase (roles?). How are they named? Go over slide 41-43!! |
