Index case is the -: (A) First case in a community, (B) Case getting infection from primary case, (C) Case getting infection from secondary case, (D) First case detected by investigator
Answer is D. Ans. is 'd' i.e., First case defected by investigator [Ref: Park 22nd/e d. 92 & 21st/e p. 9/1o Primary caseo Index case--First case of communicable disease introduced into the population.First case to come to attention of the investigator.o It is not always necessary that primary case will be index case : -When the first case noticed by the investigator is also the first case of the population - Primary case and index case are the same.When the first case nociced by the investigator is not the first case of the population (primary case) - Index case and primary case are different.o Secondary cases - Cases those developing from contact with primary case.