If the objective of the investigator is to assess the incidence of tuberculosis infection in a community, the most appropriate methodology would be to-
Identify all individuals with positive tuberculin test
Perform sputum examination of chest symtomatics
Identify new conveers to Tuberculin test
Screen all under-five children with Tuberculin test
Ans. is 'c' i.e., Identify new conveers to tuberculin test Incidence of infection o It is the percentage of population under study who will be newly infected by mycobacterium tuberculosis among the non infected of the preceding survey during the course of one year . o Persons newly infected with mycobacterium T.B. can be easily detected by new conveors to tuberculin test (remember positive tuberculin test indicates that the person is infected with M Tuberculosis); it does not prove that the person is suffering from disease. o Therefore the incidence of infection is also called "Tuberculin conversion index". o This parameter is considered one of the best indicators for evaluating the tuberculosis problem and its trend.