Indicator used in RNTCP to measure the impact of the control measures is:

Ans. c. Annual infection rate (Ref: Park 23/e p178,179, 185 22/e p168)Indicator used in RNTCP to measure the impact of the control measures is annual infection rate.'Incidence of infection: This parameter is considered one of the best indicators for evaluating the tuberculosis problem, its trend and effectivity of control programme.'- Park 22/e p168Epidemiological IndicesIndices or parameters are needed to measure the tuberculosis problem in a community as well as for planning and evaluation of control measures.Indices are also required for international comparisons.The following epidemiological indices are generally used in tuberculosis problem measurement and programme strategy:Prevalence of infection:It is the percentage of individuals who show a positive reaction to the standard tuberculin test.When the test is done in defined age-groups, it yields age-specific prevalence which is a far superior indicator than the mere percentage of positive reactors in the total population.Incidence of infection (Annual Infection Rate/Tuberculin conversion index):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.It reflects the annual risk of being infected (or re-infected) in a given community.In developing countries, every 1% of annual risk of infection is said to correspond to 50 new cases of smear-positive pulmonary tuberculosis, per year for 100,000 general population.This parameter is considered one of the best indicators for evaluating the tuberculosis problem, its trend and effectivity of control programme.Prevalence of disease or case rate:It is the percentage of individuals whose sputum is positive for tubercle bacilli on microscopic examinationQ. Incidences of new cases:It is the percentage of new confirmed tuberculosis cases per 1,000 population occuring during one yearQ. Prevalence of 'suspect' cases:This is based on X-ray examination of chestQ.Therefore, no epidemiological significance can be attached to this index.