Prevalence of tuberculosis among tribes aged 15 and above in Tamil Nadu. A community based cross-sectional study

Tuberculosis (TB) is a major public health problem in India, particularly with very limited information on TB among the tribes. This cross sectional descriptive study aims to estimate the prevalence of TB among tribal groups; understand the socio cultural determinants as risk factors for TB, and understand the knowledge attitude and practices regarding TB among Tribal population.

A multistage cluster sampling design was adopted. Tribal population >70% formed the sampling frame for selection of villages. Probability Proportional to Size (PPS) sampling method was used to select villages within the districts Villupuram, Namakkal, Nilgiris. The required sample size was estimated to be 2400 adults aged ≥15 years with an assumed prevalence of 387/100,000 bacteriological positive cases with a precision of 15% at 95% confidence level and design effect of 1.3.

A total of 2945 respondents were included in the analysis wherein approximately 87% were tribes and around 13% were non tribes. The point prevalence of TB estimated among the tribes was 196/100,000 population, and the period prevalence was reported to be 1605/100,000. About 46% of the respondents were found to be illiterate, 19.7% had their own cultivation and 31.5% reported that they consume alcohol, about 60% of them reported to consume alcohol used Indian Made Foreign Liquor. About 85% people in the 3 study sites have heard about TB, among them 66% did not know the causation and approximately 31% reported TB to be spread through air.

The present study could be beneficial for the prevention of TB in tribal population and emphasize the necessity for health education efforts to promote knowledge about TB among tribes. This study provides important information on the burden of TB and would help design an innovative model for policy makers and health managers to address TB in the tribal population of Tamilnadu.