Prevalence and factors associated with tuberculosis infection in India.

BACKGROUND: The risk of tuberculosis (TB) disease is higher in individuals with TB infection. In a TB endemic country like India, it is essential to understand the current burden of TB infection at the population level. The objective of the present analysis is to estimate the prevalence of TB infection in India and to explore the factors associated with TB infection. METHODS: Individuals aged > 15 years in the recently completed National TB prevalence survey in India who were tested for TB infection by QuantiFERON-TB Gold Plus (QFT-Plus) assay were considered for this sub-analysis. TB infection was defined as positive by QFT-Plus (value >0.35 IU/ml). The estimates for prevalence, prevalence ratio (PR) and adjusted risk ratio (aRR) estimates with 95% confidence intervals (CIs) were calculated. RESULTS: Of the 16864 individuals analysed, the prevalence of TB infection was 22.6% (95% CI:19.4 -25.8). Factors more likely to be associated with TB infection include age > 30 years (aRR:1.49;95% CI:1.29-1.73), being male (aRR:1.26; 95%CI: 1.18-1.34), residing in urban location (aRR:1.58; 95%CI: 1.03-2.43) and past history of TB (aRR:1.49; 95%CI: 1.26-1.76). CONCLUSION: About one fourth (22.6%) of the individuals were infected with TB in India. Individuals aged > 30 years, males, residing in urban location, and those with past history of TB were more likely to have TB infection. Targeted interventions for prevention of TB and close monitoring are essential to reduce the burden of TB in India.

Pulmonary Mycobacterium abscessus and response to treatment in an outpatient setting: Case series.

Pulmonary disease due to Mycobacterium abscessus (Mab) has become an increasing cause of health concern, particularly among individuals infected with nontuberculous mycobacteria. Since Mab is intrinsically resistant to many antibiotics, it is very challenging to treat patients with symptomatic disease. In this case series, we report four patients with symptomatic pulmonary Mab who had prior history of antituberculosis treatment intake and declared cured at the end of treatment. The current episode was confirmed to be due to Mab infection by molecular and clinical diagnosis and received species specific-antibiotics therapy. All were periodically monitored for the sputum smear and culture conversions throughout the treatment period. The clinical course was variable though all received similar antibiotic regimen and showed varied treatment outcomes. The time of diagnosis and the treatment outcome indicate that a better understanding of host-pathogen interactions is essential for the successful treatment of pulmonary Mab infection.

Population-Based Serosurvey for Severe Acute Respiratory Syndrome Coronavirus 2 Transmission, Chennai, India.

We conducted a cross-sectional survey to estimate the seroprevalence of IgG against severe acute respiratory syndrome coronavirus 2 in Chennai, India. Among 12,405 serum samples tested, weighted seroprevalence was 18.4% (95% CI 14.8%-22.6%). These findings indicate most of the population of Chennai is still susceptible to this virus.

SARS-CoV-2 antibody seroprevalence in India, August-September, 2020: findings from the second nationwide household serosurvey.

BACKGROUND: The first national severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serosurvey in India, done in May-June, 2020, among adults aged 18 years or older from 21 states, found a SARS-CoV-2 IgG antibody seroprevalence of 0·73% (95% CI 0·34-1·13). We aimed to assess the more recent nationwide seroprevalence in the general population in India. METHODS: We did a second household serosurvey among individuals aged 10 years or older in the same 700 villages or wards within 70 districts in India that were included in the first serosurvey. Individuals aged younger than 10 years and households that did not respond at the time of survey were excluded. Participants were interviewed to collect information on sociodemographics, symptoms suggestive of COVID-19, exposure history to laboratory-confirmed COVID-19 cases, and history of COVID-19 illness. 3-5 mL of venous blood was collected from each participant and blood samples were tested using the Abbott SARS-CoV-2 IgG assay. Seroprevalence was estimated after applying the sampling weights and adjusting for clustering and assay characteristics. We randomly selected one adult serum sample from each household to compare the seroprevalence among adults between the two serosurveys. FINDINGS: Between Aug 18 and Sept 20, 2020, we enrolled and collected serum samples from 29 082 individuals from 15 613 households. The weighted and adjusted seroprevalence of SARS-CoV-2 IgG antibodies in individuals aged 10 years or older was 6·6% (95% CI 5·8-7·4). Among 15 084 randomly selected adults (one per household), the weighted and adjusted seroprevalence was 7·1% (6·2-8·2). Seroprevalence was similar across age groups, sexes, and occupations. Seroprevalence was highest in urban slum areas followed by urban non-slum and rural areas. We estimated a cumulative 74·3 million infections in the country by Aug 18, 2020, with 26-32 infections for every reported COVID-19 case. INTERPRETATION: Approximately one in 15 individuals aged 10 years or older in India had SARS-CoV-2 infection by Aug 18, 2020. The adult seroprevalence increased approximately tenfold between May and August, 2020. Lower infection-to-case ratio in August than in May reflects a substantial increase in testing across the country. FUNDING: Indian Council of Medical Research.

Prevalence of SARS-CoV-2 infection in India: Findings from the national serosurvey, May-June 2020.

BACKGROUND & OBJECTIVES: Population-based seroepidemiological studies measure the extent of SARS-CoV-2 infection in a country. We report the findings of the first round of a national serosurvey, conducted to estimate the seroprevalence of SARS-CoV-2 infection among adult population of India. METHODS: From May 11 to June 4, 2020, a randomly sampled, community-based survey was conducted in 700 villages/wards, selected from the 70 districts of the 21 States of India, categorized into four strata based on the incidence of reported COVID-19 cases. Four hundred adults per district were enrolled from 10 clusters with one adult per household. Serum samples were tested for IgG antibodies using COVID Kavach ELISA kit. All positive serum samples were re-tested using Euroimmun SARS-CoV-2 ELISA. Adjusting for survey design and serial test performance, weighted seroprevalence, number of infections, infection to case ratio (ICR) and infection fatality ratio (IFR) were calculated. Logistic regression was used to determine the factors associated with IgG positivity. RESULTS: Total of 30,283 households were visited and 28,000 individuals were enrolled. Population-weighted seroprevalence after adjusting for test performance was 0.73 per cent [95% confidence interval (CI): 0.34-1.13]. Males, living in urban slums and occupation with high risk of exposure to potentially infected persons were associated with seropositivity. A cumulative 6,468,388 adult infections (95% CI: 3,829,029-11,199,423) were estimated in India by the early May. The overall ICR was between 81.6 (95% CI: 48.3-141.4) and 130.1 (95% CI: 77.0-225.2) with May 11 and May 3, 2020 as plausible reference points for reported cases. The IFR in the surveyed districts from high stratum, where death reporting was more robust, was 11.72 (95% CI: 7.21-19.19) to 15.04 (9.26-24.62) per 10,000 adults, using May 24 and June 1, 2020 as plausible reference points for reported deaths. INTERPRETATION & CONCLUSIONS: Seroprevalence of SARS-CoV-2 was low among the adult population in India around the beginning of May 2020. Further national and local serosurveys are recommended to better inform the public health strategy for containment and mitigation of the epidemic in various parts of the country.

Correction: Assessment of lung function in successfully treated tuberculosis reveals high burden of ventilatory defects and COPD.

[This corrects the article DOI: 10.1371/journal.pone.0217289.].

Assessment of lung function in successfully treated tuberculosis reveals high burden of ventilatory defects and COPD.

BACKGROUND: Burden, phenotype and risk-factors of lung function defects in successfully treated tuberculosis cases are unclear. METHODS: We performed spirometry with bronchodilators in new drug-sensitive adult (≥18 years) pulmonary tuberculosis cases during the 12 months following successful treatment in India. Airflow obstruction was defined as pre-bronchodilator FEV1/FVC<5th percentile of Global Lung Initiative mixed-ethnicity reference (lower limit of normal [LLN]). Chronic obstructive pulmonary disease (COPD) was defined as post-bronchodilator FEV1/FVC