One TB infected person can infect how many people in lyr -
Ans. is 'c'i.e., 10 o Tuberculosis is transmitted mainly by droplet infection and dropled nuclei generated by sputum-positive patients with pulmonary tuberculosis.o Coughing generates the largest number of droplets of all sizes. The frequency and vigour of cough and the ventilation of the environment influence transmission of infection,o Patient with infectious pulmonary tuberculosis disease can infect 10-15 persons in a year.Epidemiological indices of tuberculosiso Indices or parameters are needed to measure the tuberculosis problem in a community as well as for planning and evaluation of control measures.o The following epidemiological-indices are used in tuberculosis problem measurement and programme strategy' :-Prevalence of infectionIt is the percentage of individuals who show a positive reaction to the standard tuberculin test.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- in fected of the preceding survey during the course of one year.It reflects the annual risk of being infected (or reinfected) in a given community, i.e. it expresses the attacking force of tuberculosis in a community.It is also known as tuberculin conversion index.This parameter is considered one of the best indicators for evaluating the tuberculosis problem and its trend.Prevalence of disease or case rateIt is the percentage of individuals w hose sputum is positive for tubercle bacilli on microscopic examination.It is the best available practical index to estimate the number of infectious cases or case load in a community.Incidence of new casesIt is the percentage of new TB cases (confirmed by bacteriological examination) per 1CKK) population occurring during one yearPrevalence of suspected casesThis is based on X-ray examination of chest.Prevalence of drug resistant casesIt is the prevalence of patient excreting tubercle bacilli resistant to anti-tubercular drugs.Mortality rateThe number of deaths from tuberculosis every year per 1,000 population.
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Communicable Diseases