BackgroundThree rounds of a repeated cross-sectional serosurvey to estimate the seroprevalence and trends of SARS-CoV-2 were conducted from August-October’ 2020 in the state of Delhi in India in the general population aged ≥5 years.MethodsThe selection of participants was through a multi-stage sampling design from all the 11 districts and 280 wards of the city-state, with two-stage allocation proportional to population- size. Household selected was via systematic random sampling, and individual participant selection through the age-order procedure. The blood samples were screened using the IgG ELISA COVID-Kawach kit (August Round), and the ERBALISA COVID-19 IgG (September and October) rounds. The seroprevalence was estimated by applying the sampling weights based on age and sex with further adjustment for the assay-kit characteristics.ResultsA total of 4267 (n=15046), 4311 (n=17409), and 3829 (n=15015) positive tests indicative of the presence of IgG antibody to SARS-CoV-2 were observed during the August, September, and October 2020 serosurvey rounds, respectively. The adjusted seroprevalence declined from 28.39% (95% CI 27.65-29.14) (August) to 24.08% (95% CI 23.43-24.74) (September), and 24.71% (95% CI 24.01, 25.42%) (October). The antibody positivity was highest in the ≥50 and female age-group during all rounds of the serosurvey, while the decline was maximum among the younger age-group (5-17 years). On adjusted analysis, participants with lower per capita income, living in slums or overcrowded households, and those with diabetes comorbidity had significantly higher statistical odds of antibody positivity.ConclusionsDespite high IgG seroprevalence, there was evidence for waning of antibody positivity with the progression of the COVID-19 epidemic, implying a potential reduction in population immunity, especially if also associated with the lack of trained T cell immunity.

BackgroundWe report the findings of a large follow-up, community-based, cross-sectional serosurvey and correlate it with the coronavirus disease (COVID-19) test-positivity rate and the caseload observed between the peaks of the first and the second wave of the COVID-19 pandemic in Delhi, India. MethodologyIndividuals aged five and above were recruited from 274 wards of the state (population approximately 19.6 million) from January 11 to January 22, 2021. A total of 100 participants each were included from all wards for a net sample size of approximately 28,000. A multistage sampling technique was employed to select participants for the household serosurvey. Anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoglobulin (IgG) antibodies were detected by using the VITROS® (Ortho Clinical Diagnostics, Raritan, NJ, USA) assay (90% sensitivity, 100% specificity). ResultsAntibody positivity was observed in 14,298 (50.76%) of 28,169 samples. The age, sex, and district population-weighted seroprevalence of the SARS-CoV-2 IgG was 50.52% (95% confidence interval [CI] = 49.94-51.10), and after adjustment for assay characteristics, it was 56.13% (95% CI = 55.49-56.77). On adjusted analysis, participants aged ≥50 years, of female gender, housewives, having ever lived in containment zones, urban slum dwellers, and diabetes or hypertensive patients had significantly higher odds of SARS-CoV-2 antibody positivity.The peak infection rate and the test-positivity rate since October 2020 were initially observed in mid-November 2020, with a subsequent steep declining trend, followed by a period of persistently low case burden lasting until the first week of March 2021. This was followed by a steady increase followed by an exponential surge in infections from April 2021 onward culminating in the second wave of the pandemic. ConclusionsThe presence of infection-induced immunity from SARS-CoV-2 even in more than one in two people can be ineffective in protecting the population. Despite such high seroprevalence, population susceptibility to COVID-19 can be accentuated by variants of concern having the ability for rapid transmission and depletion of antibody levels with the threat of recurrent infections, signifying the need for mass vaccination.

Background: India has over 50 million workers employed in industries with exposure to very high sound levels, predisposing them to noise-induced hearing loss (NIHL). Methods: We conducted a systematic review and meta-analysis by using the following criteria: (1) Observational or experimental studies conducted in India; (2) English language studies; (3) Published during January 2010–December 2019; (4) Primary outcome: proportion of participants detected with NIHL. We reviewed bibliographic databases (PubMed, Scopus, and DOAJ) and Google Scholar, and extracted the relevant data. Results: A total of 160 documents were identified after removing duplicates, and 33 full texts were screened, of which 22 studies were included. The mean (SD) effective sample size of the studies was 107.1 (78.9). The pooled proportion of participants with NIHL irrespective of the category was 0.49 (95%CI: 0.22–0.76) and that of hearing loss was 0.53 (95%CI: 0.28– 0.78). Most studies reported that none of the workers, especially in the informal sectors, used auditory protection. Conclusions: NIHL is a major neglected public health occupational health challenge in India linked with adverse social determinants of health. Sustained advocacy for implementation of legislative and behavior change communication for protecting the hearing of workers is warranted.

A significant proportion of patients with coronavirus disease 2019 require timely hospitalization to reduce the risk of complications and mortality. We describe the trends of the age and gender stratified outcomes among hospitalized COVID-19 patients with moderate to severe illness at the largest dedicated tertiary care COVID-19 government hospital in New Delhi, India. A retrospective cohort study through secondary data analysis from in-patient hospital data of patients admitted from April 1 to November 15, 2020 was conducted. The data of 10,314 laboratory-confirmed patients with COVID-19 was analyzed, of which 8899 (86.28%) were discharged after recovery, and 1415 (13.72%) died. The mean (SD) age of the hospitalized patients was 46.43 (18.74) years (n = 10,309) including 6031 (58.50%) male and 4278 (41.50%) female patients (n = 10,309). On bivariate analysis, increasing age was associated with significantly higher odds of mortality in both gender (p < .001). The mortality rate in female patients was lower (11.92%) compared with male patients (15.75%) (p = .675). However, elderly women had the highest odds of mortality (p < .001), indicating the possible role of delayed health seeking behavior, secondary to familial, and social neglect. Mortality in the patients with COVID-19 also occurred early after admission suggesting rapid deterioration, delayed reporting by patients, or their late referral from other health facilities.However, the overall statewide recovery rate showed steady improvement since the onset of the pandemic. In contrast, the recovery rate among the moderatesevere cases that were hospitalized at this tertiary care center during the same period reflected a lower nonspecific zigzag pattern indicating limited effectiveness of the COVID-19 treatment regimens.

Background Three rounds of a repeated cross-sectional serosurvey to estimate the change in seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were conducted from August to October 2020 in the state of Delhi, India, in the general population ≥5 y of age. Methods The selection of participants was through a multistage sampling design from all 11 districts and 280 wards of the city-state, with multistage allocation proportional to population size. The blood samples were screened using immunoglobulin G (IgG) enzyme-linked immunosorbent assay kits. Results We observed a total of 4267 (N=150 46), 4311 (N=17 409) and 3829 (N=15 015) positive tests indicative of the presence of IgG antibody to SARS-CoV-2 during the August, September and October 2020 serosurvey rounds, respectively. The adjusted seroprevalence declined from 28.39% (95% confidence interval [CI] 27.65 to 29.14) in August to 24.08% (95% CI 23.43 to 24.74) in September and 24.71% (95% CI 24.01 to 25.42) in October. On adjusted analysis, participants with lower per capita income, living in slums or overcrowded households and those with diabetes comorbidity had significantly higher statistical odds of having antibody positivity (p&lt;0.01). Conclusions Nearly one in four residents in Delhi, India ≥5 y of age had the SARS-CoV-2 infection during August–October 2020.