Point source epidemic is:
Ans. (b) Sharp rise and sharp fall in number of casesRef: K. Park 23rd ed. / 64, 93Types of Epidemics* Point source or single exposure epidemics# Sharp rise and sharp fall in number of cases# Clustering of cases in narrow spectrum of time# All cases develop within one incubation period of disease.# Ex: Food poisoning, measles, chicken pox, Bhopal gas tragedy* Common source, continuous or repeated exposure epidemics:# Sharp rise in number of cases# Fall in number of cases is interrupted by secondary waves/peaks# Ex: Contaminated well in a village, Sex worker in a gonorrhea outbreak* Propagated epidemics:# Gradual rise and gradual fall over a long time (tail off)# Results from person to person transmission# Transmission continues till number of susceptible is depleted or they are no longer exposed to infected individuals# Ex: HIV, TuberculosisAlso Know* Endemic: constant presence of a disease in a defined geographical area* Pandemic: epidemic affecting a large population, occurring over a large geographical area.* Sporadic: scattered cases. They are widely separated in space and time and shows little or no connection.
Gradual rise and gradual fall in number of cases
Sharp rise and sharp fall in number of cases
Sharp rise and fall is interrupted by secondary waves
Gradual rise and fall is interrupted by secondary waves
Epidemiological Study