Epidemiology

Front 1

endemic

Back 1

constant presence of a disease or infectious agent within a given area or population and may also refer to the usual occurrence (incidence/prevalence)

Front 2

epidemic

Back 2

the occurrence of cases of an illness, health related behavior in an community or region that is clearly in excess of normal

Front 3

outbreak

Back 3

an epidemic limited to a localized area that is clearly in excess of normal

Front 4

attack rate

Back 4

the cumulative incidence of infection in a group observed over a period during an epidemic

Front 5

epi curve

Back 5

help identify causes

Front 6

infectivity

Back 6

the ability of an agent to cause infection in a susceptible host

Front 7

pathogenicity

Back 7

the ability of a microbial agent to induce disease

Front 8

virulence

Back 8

the severity of the diease after the infection occurs (case fatality rate, the proportion of cases that develop severe disease)

Front 9

host factors

Back 9

age, sex, geography, occupation, immunity, religious customs

Front 10

R0

Back 10

the average number of persons infected by each case in a totally susceptible population

Front 11

net repro rate

Back 11

R1, depends on the R0 and the proportion of contacts who are immune

Front 12

R0 >1

Back 12

disease will cause epidemic

Front 13

R0 = 1

Back 13

disease will become endemic

Front 14

R0 <1

Back 14

disease will eventually disappear, each infected person infects less than one person, necessary to prevent outbreaks

Front 15

herd immunity

Back 15

the immunity of a group or community, the resistance of a group to invasion and spread of an infectious agent