32. Infectious disease Epi

Question 1

direct vs indirect transmission?

Answer 1

direct: person to person like respiratory droplet in the flu or contact w/scabies

indirect: common vehicle like the air (TB), water (cryptosporidiosis) or food (E.coli O157:h7)
or vector like insects (malaria, chikungynya, west nile virus/mosquitoes or animals like bats, dogs/rabies)

Question 2

definition of an outbreak?

Answer 2

increase in cases over expected rates (per population)

Question 3

oubreak definition for not foodborne illness?

Answer 3

3+ cases of disease that occurs in individuals not living in the same housefold, but who are epidemiologically linked

Question 4

outbreak definition for a foodborne illness?

Answer 4

2+ epidemiologically realted cases of illness following consumption of a common food item or one case of botulism, cholera, mushroom poisoning, trichinosis, fish poisoning

Question 5

egs of rare and severe diseases in which one case is considered worthy of an investigation to stop an outbreak?

Answer 5

rabies (human)

pneumonic plague

anthrax

smallpox

ebola

Question 6

why do we investigate outbreaks?

Answer 6

to prevent further cases

to discover and describe new disease (emerging pathogens)

to learn new mechanisms of transmission for old diseases

to evaluate existing prevention strategies

to address public concern about the outbreak

to prevent future outbreaks

Question 7

a case definition should specify the clinical syndrome of interest with restrictions on what?

Answer 7

time, place, person

Question 8

probable vs confirmed case?

Answer 8

probable: no lab criteria available but meets clinical case definition
confirmed: clinical case definition met plus lab criteria met

Question 9

sensitivity?

Answer 9

a/(a+c) = correctly identify all that have the new infection

Question 10

specificity?

Answer 10

d/(b+d) = correctly identify those WITHOUT the new infection

Question 11

attack rate?

Answer 11

of cases/# of people at risk

cases/ (#cases + #controls from same base pop at risk)

Question 12

eg of a single exposure epidemic curve?

Answer 12

food poisoning at a party

Question 13

eg of a multiple exposure epidemic curve?

Answer 13

same food eaten at two different events

Question 14

eg of a continuous exposure epidemic curve?

Answer 14

legionella outbreak - air conditioning cooling towers - NOT transmitted person to person (common vehicle is air conditioning tower that is on all of the time)

Question 15

eg of a person-to-person transmission?

Answer 15

eg flu (index case then see multiple mini outbreaks - each represents a time)

Question 16

incubation period?

Answer 16

interval from receipt or transmission of infection to onset of clinical illness

person has no sxs

may or may not be able to transmit disease

Question 17

odds ratio?

Answer 17

odds of exposure in cases/odds of exposure in controls