Flashcards in L32 Deck (14)
What is the epidemiological triad?
Host, agent, environment
United by a vector
What is the example for direct transmission?
Person to person
What are the 2 examples of indirect transmission?
Common vehicle (air, water, food)
Vector (insect, animal)
Define outbreak. What is the rate equation?
Increased event incidence vs expected rates
= new cases/population at risk
Depends on type of outbreak & setting
How many infected people determine a foodborne disease outbreak?
2+ related illness following consumption of common food item
What are the 3 aspects of a case definition?
1. Time & place
2. Restrictions: person details like age, gender, ethnicity
3. Clinical criteria: symptoms & clinical tests
What are limits that challenge the development of case definition?
New definition of the disease
Emerging clinical picture
Lab tests are limited or not definitive
Define sensitivity, include the equation.
Correctly identify new infection
Define specificity, include the equation.
True negatives - people who don't have infection
Why do you want lower false positives?
Increases positive predictive value (PPV)
What is the x axis for the epidemic curve? Y axis?
X = time (period, used in rate calculation)
Y = # cases
What are the options for the shape of the epidemic curve?
Person to person transmission
What are 2 things your disease hypothesis should contain?
Source of infection
Mode of transmission