Anergy to purified protein derivative and chronic energy deficiency in sputum-positive pulmonary tuberculosis: Dynamic assessment at baseline and treatment completion.

Background: Tuberculosis (TB) remains a high burden disease in India. Nutrition plays a pivotal role in holistic recovery of the same. Methods: Patients with sputum positive pulmonary TB were consecutively recruited into the study aimed to observe the incidence of under nutrition and anergy purified protein derivative (PPD). Anthropometry and PPD testing were done at baseline. Patients were followed-up at 6 months, with PPD intradermal test repeated to study tuberculin conversion. Nutritional recovery, tuberculin conversion, and determination of persistent anergy were the outcomes of interest. Results: Of the 134 patients enrolled in the study, 43.2% were anergic to PPD at baseline. While 50.8% patients had normal body mass index (BMI), 14.2%, 9.7%, and 25.4% had chronic energy deficiency (CED) Grades I, II, and III, respectively. BMI at baseline showed a positive linear correlation with PPD response (r = 0.44, P < 0.001), and anergy was associated with CED (odds ratio - 3.25, P = 0.001). Forty-six patients completed follow-up and 19.6% showed anergy to PPD. At follow-up, 69.6% had normal BMI. Overall, there was an improvement in anthropometry and PPD reactivity in patients at 6 months, compared to baseline assessment. Conclusion: Anergy was significantly associated with CED at baseline in patients with TB. While most patients had an improvement in nutritional status and PPD reactivity, a small subset of patients had persistent anergy. Recovery from TB is multifactorial and its determinants include microbiological cure, nutritional status, and immunological recovery.

Risk of COVID-19 re-infection and its predictors (CORES): protocol for a community-based longitudinal cohort study in Vellore, India.

INTRODUCTION: The incidence of SARS-CoV-2 re-infection has not been widely evaluated in low-income and middle-income countries. Understanding immune responses elicited by SARS-CoV-2 natural infection and factors that lead to re-infection in a community setting is important for public health policy. We aim to investigate the risk of primary infection and re-infection among those without and with evidence of prior infection as defined by the presence of antibodies to SARS-CoV-2 spike protein. METHODS AND ANALYSIS: A baseline seroprevalence survey will test for SARS-CoV-2 antibodies among healthy adults in Vellore, India. Based on an expected seropositivity rate of 50% in the general population, with annual attack rates of 12%, 6%, 4.8% and 4% among those unvaccinated and seronegative, vaccinated and seronegative, unvaccinated and seropositive, and vaccinated and seropositive, respectively, we will recruit 1200 adults who will be followed up for a total of 24 months. Weekly self-collected saliva samples will be tested by reverse transcription-PCR (RT-PCR) to detect SARS-CoV-2 infections, for a period of 1 year. For any person testing RT-PCR positive, blood samples will be collected within 2 days of RT-PCR positivity and on days 30 and 90 to assess the kinetics and longevity of the antibody responses, B cell memory and T cell memory post-infection. The data will be analysed to estimate seroprevalence at baseline and over time, the risk factors for infection, rates of primary infection and re-infection, and provide a comparison of the rates across groups based on infection and vaccination status. ETHICS AND DISSEMINATION: The study has been approved by the Institutional Review Board (IRB No: 13585) of Christian Medical College and Hospital, Vellore. The results of the study will be made available through journal publications and conference presentations. TRIAL REGISTRATION NUMBER: Central Trial Registry of India: CTRI/2020/11/029438.