Household symptomatic contact screening of newly diagnosed sputum smears positive tuberculosis patients - An effective case detection tool

OBJECTIVES: Primary objective was to assess the prevalence of tuberculosis (TB) among household contacts of newly diagnosed sputum smear (SS) positive TB index cases. Secondary objectives were the evaluation of risk factors in household contacts for acquiring TB disease; and the evaluation of various characteristics of index cases which influence the transmission of disease to household contacts. SETTINGS AND DESIGN: This exploratory cohort study included 521 household contacts of 133 newly diagnosed SS positive TB patients who were registered under the Revised National Tuberculosis Control Program at the Directly Observed Treatment-Short Course Centres of District Tuberculosis Centre, Kolhapur, Maharashtra from July 1, 2013 to February 28, 2014 (8 months). SUBJECTS AND METHODS: Household contacts with symptoms suggestive to TB were subjected to SS examination of two samples for acid fast bacilli by Ziehl-Neelsen staining and for X-ray chest postero-anterior view. Presence of risk factors in symptomatic contacts was also recorded. RESULTS: Eighteen contacts out of 521 (3.45%) had symptoms suggestive of TB. Of these, 6 contacts were diagnosed to have TB; 5 being sputum positive cases and one with X-ray suggestive of TB; giving a prevalence of 1.15 %. The study achieved a yield of 4.51% secondary cases. CONCLUSIONS: Household contact screening of newly diagnosed TB index cases provides modest yield of cases. Relatively fewer secondary symptomatic persons need to be investigated by this method for achieving additional yield proving it to be a practical and feasible approach.