<prompt> True about point source epidemic is?Occurs in more than 1 incubation periodOccurs in one incubation periodThe exposure is continuousEpidemic curve falls very slowly  <response>: Common source single exposure epidemics is also known as point source epidemic. The exposure to the disease agent is brief and essentially simultaneous, the resultant cases all develop within one incubation period of the disease. Ref: 25th edition, Parks Textbook of Preventive and Social Medicine, Page no. 72 