Secondary attack rate is defined as-
Ans. is 'b' i.e., Number of cases developing disease within incubation period following exposure to primary case * SAR is defined as "the number of exposed persons developing the disease within the range of incubation period, following exposure to primary case".SAR=No of exposed persons developing disease within the range of the incubation period----------------------------------------Total number of exposed/susceptible contactx 100
Number of total cases developing disease within maximum incubation period
Number of case developing disease within incubation period following exposure to primary care
Number of cases developing diseare after exposure to primary case in any period of time
Number of cases developing after exposure to secondary case
Epidemiology