Tuberculin conversion index is a measure of -

Ans. is 'c' i.e., Incidence of infection Incidence of infection (Annual infection rate)It is the percentage of population under study who will be newly infected by M.tuberculosis among the non-infected of the preceding survey during the course of one year.It expresses the attacking force of tuberculosis and is also known as tuberculin conversion index i.e. percentege of new people becoming tuberculin positive.In developing countries, every 1% of annual infection rate is said to correspond to 50 new cases of smear positive pulmonary TB, per year, for 100000 general population.It is the best indicator for evalution of TB problem and its trend.In India, annual infection rate/tuberculin conversion index is 1.7%.