The potential impact of the COVID-19 response related lockdown on TB incidence and mortality in India.

India has the highest burden of incident tuberculosis (TB) cases and deaths globally. TB is strongly associated with poverty and this risk is largely mediated by undernutrition in India. COVID-19 response related lockdown has resulted in an economic crisis which may double levels of poverty, has exacerbated food insecurity, and disrupted TB services. These developments may have serious implications for TB progression and transmission in India. The nutritional status of a population is a strong determinant of the TB incidence, and undernutrition in adults alone accounts for 32-44% of TB incidence in India. A systematic review has shown that a 14% increase in TB incidence can occur per one unit decrease in body mass index (BMI), across the BMI range of 18.5-30 kg/m2. We believe that one unit decrease in BMI (corresponding to a 2-3 kg weight loss) may result in the poor in India as a result of the lockdown and its aftermath. This may result in an increase in estimated (uncertainty interval) incident TB by 185 610 (180 230, 190 990) cases. A 59% reduction in TB case detection between end March and May 2020, may result in an estimated (uncertainty interval) additional 87 711 (59 998, 120 630) TB deaths [19.5% increase (14.5, 24.7)] in 2020. Disadvantaged social groups and those living in states with higher levels of poverty, under-nutrition,and migrant workers are at particular risk. We suggest enhanced rations including pulses through the public distribution system and direct cash transfers to the poor pending restoration of livelihoods. TB services should be resumed immediately with enhanced efforts at case detection including active case finding. To prevent deaths among TB detected within the national TB programme, systemic identification, referral and management of severe disease at notification should be considered.