Flashcards in 32. Infectious disease Epi Deck (17)
direct vs indirect transmission?
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)
definition of an outbreak?
increase in cases over expected rates (per population)
oubreak definition for not foodborne illness?
3+ cases of disease that occurs in individuals not living in the same housefold, but who are epidemiologically linked
outbreak definition for a foodborne illness?
2+ epidemiologically realted cases of illness following consumption of a common food item or one case of botulism, cholera, mushroom poisoning, trichinosis, fish poisoning
egs of rare and severe diseases in which one case is considered worthy of an investigation to stop an outbreak?
why do we investigate outbreaks?
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
a case definition should specify the clinical syndrome of interest with restrictions on what?
time, place, person
probable vs confirmed case?
probable: no lab criteria available but meets clinical case definition
confirmed: clinical case definition met plus lab criteria met
a/(a+c) = correctly identify all that have the new infection
d/(b+d) = correctly identify those WITHOUT the new infection
# of cases/# of people at risk
# cases/ (#cases + #controls from same base pop at risk)
eg of a single exposure epidemic curve?
food poisoning at a party
eg of a multiple exposure epidemic curve?
same food eaten at two different events
eg of a continuous exposure epidemic curve?
legionella outbreak - air conditioning cooling towers - NOT transmitted person to person (common vehicle is air conditioning tower that is on all of the time)
eg of a person-to-person transmission?
eg flu (index case then see multiple mini outbreaks - each represents a time)
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