Severe undernutrition in children affects tuberculin skin test performance in Southern India.

BACKGROUND: Undernutrition impairs immunity to Mycobacterium tuberculosis and is a risk factor for tuberculosis disease (TB). We aim to investigate if severe undernutrition affects the tuberculin skin test (TST) response among household contacts (HHCs) of pulmonary TB cases. METHODS: We analyzed data from HHCs (> five years) of pulmonary TB cases in Southern India. Undernutrition was defined as per World Health Organization based on body mass index (BMI) for adults (undernutrition 16-18.4 and severe undernutrition <16 kg/m2) and BMI relative to the mean for children (undernutrition 2SD-3SD and severe undernutrition < 3SDs below mean). Univariate and multivariate models of TST positivity (> five mm) were calculated using logistic regression with generalized estimating equations. RESULTS: Among 1189 HHCs, 342 were children (age 5-17 years) and 847 were adults. Prevalence of TST positivity in well-nourished, undernourished and severely undernourished children was 135/251 (53.8%), 32/68 (47.1%), and 7/23 (30.4%) respectively; among adults, prevalence of TST positivity was 304/708 (42.9%), 43/112 (38.4%) and 12/26 (46.2%), respectively. Severe undernutrition in children was associated with decreased odds of TST positivity (adjusted odds ratio 0.3; 95%CI 0.1-0.9). CONCLUSION: Severe undernutrition in children was associated with decreased odds of TST positivity. False-negative TSTs may result from undernutrition; caution is warranted when interpreting negative results in undernourished populations.

Risk factors for death during treatment in pulmonary tuberculosis patients in South India: A cohort study.

OBJECTIVE: Identifying the risk factors for deaths during tuberculosis (TB) treatment is important for achieving the vision of India's National Strategic Plan of 'Zero Deaths' by 2025. We aimed to determine the proportion of deaths during TB treatment and its risk factors among smear positive pulmonary TB patients aged more than 15 years. STUDY DESIGN: We performed a cohort study using data collected for RePORT India Consortium (Regional Prospective Observational Research in Tuberculosis). SETTING: Revised TB Control Program (RNTCP) in three districts of South India. PARTICIPANTS: The cohort consisted of newly diagnosed drug sensitive patients enrolled under the Revised National TB Control Program during 2014-2018 in three districts of southern India. Information on death was collected at homes by trained project staff. PRIMARY OUTCOME MEASURES: We calculated 'all-cause mortality' during TB treatment and expressed this as a proportion with 95% confidence interval (CI). Risk factors for death were assessed by calculating unadjusted and adjusted relative risks with 95% CI. RESULTS: The mean (SD) age was of the 1167 participants was 45 (14.5) years and 79% of them were males. Five participants (0.4%) were HIV infected. Among the males, 560 (61%) were tobacco users and 688 (75%) reported consuming alcohol. There were 47 deaths (4%; 95% CI 3.0-5.3) of which 28 deaths (60%) occurred during first two months of treatment. In a bi-variable analysis, age of more than 60 years (RR 2.27; 95%CI: 1.24-4.15), male gender (RR 3.98; 95% CI: 1.25-12.70), alcohol use in last 12 months (RR 2.03; 95%CI: 1.07-3.87), tobacco use (RR 1.87; 95%CI: 1.05-3.36) and severe anaemia (RR 3.53: 95%CI: 1.34-9.30) were associated with a higher risk of death. In adjusted analysis, participants with severe anaemia (<7gm/dl) had 2.4 times higher risk of death compared to their counterparts. CONCLUSION: Though deaths during TB treatment was not very high, early recognition of risk groups and targeted interventions are required to achieve zero TB deaths.

Interaction of nutritional status and diabetes on active and latent tuberculosis: a cross-sectional analysis.

BACKGROUND: Malnutrition and diabetes are risk factors for active tuberculosis (TB), possible risk factors for latent TB infection (LTBI), and may interact to alter their effect on these outcomes. Studies to date have not investigated this interaction. METHODS: We enrolled 919 newly diagnosed active TB patients and 1113 household contacts at Primary Health Centres in Puducherry and Tamil Nadu, India from 2014 to 2018. In cross-sectional analyses, we used generalized estimating equations to measure additive and multiplicative interaction of body mass index (BMI) and diabetes on two outcomes, active TB and LTBI. RESULTS: Among overweight or obese adults, active TB prevalence was 12-times higher in diabetic compared to non-diabetic participants, 2.5-times higher among normal weight adults, and no different among underweight adults (P for interaction < 0.0001). Diabetes was associated with 50 additional active TB cases per 100 overweight or obese participants, 56 per 100 normal weight participants, and 17 per 100 underweight participants (P for interaction < 0.0001). Across BMI categories, screening 2.3-3.8 active TB patients yielded one hyperglycemic patient. LTBI prevalence did not differ by diabetes and BMI*diabetes interaction was not significant. CONCLUSIONS: BMI and diabetes are associated with newly diagnosed active TB, but not LTBI. Diabetes conferred the greatest risk of active TB in overweight and obese adults whereas the burden of active TB associated with diabetes was similar for normal and overweight or obese adults. Hyperglycemia was common among all active TB patients. These findings highlight the importance of bi-directional diabetes-active TB screening in India.