Incidence of mycobacterial disorders in Indian adult male service population followed for over two decades.

BACKGROUND: The comprehensive epidemiology of mycobacterial disorders is scarce from our country. The incidence of Tuberculosis (TB) and Leprosy in a cohort of military personnel followed for a long duration was evaluated in this study.

METHODS: The data for this descriptive epidemiologic study was derived from the electronic medical records (EMR) data of the service personnel enrolled between 1990 and 2015. They were recruited between the ages of 17 and 18 years in good health and their morbidity data was derived from the medical records. The incidence rate (IR) was calculated as per person-years (py) using appropriate statistical methods.

RESULTS: The study population includes 51,217 participants (median age 33 years, range 17-54) with a mean follow up of 12.5 years. Yearly evaluation of the data gave a cumulative follow up duration of 613,925py. A total of 530 patients developed TB, giving an IR of 86.3 per 100,000 person years (95% CI 79.2-93.9). Leprosy was diagnosed in 59 cases giving an IR of 9.6 per 100,000py (95% CI 7.4-12.3). Pulmonary (71%) and pleural (24%) locations were the most common sites of the TB infection. The data about the contribution of the mycobacterial disorders towards the mortality and the subtypes of leprosy was not available in the EMR.

CONCLUSION: Low IR of mycobacterial disorders was observed in this study when compared with the previous reports. Healthy lifestyle and good socioeconomic status could explain the low IR of mycobacterial disorders in the military personnel.