COVID-19 emerged as a global pandemic in 2020, spreading rapidly to most parts of the world. The proportion of infected individuals in a population can be reliably estimated via serosurveillance, making it a valuable tool for planning control measures. Our serosurvey study aimed to investigate SARS-CoV-2 seroprevalence in the urban population of Hyderabad at the end of the first wave of infections. This cross-sectional survey, conducted in January 2021 and including males and females aged 10 years and above, used multi-stage random sampling. 9363 samples were collected from 30 wards distributed over six zones of Hyderabad, and tested for antibodies against SARS-CoV-2 nucleocapsid antigen. Overall seropositivity was 54.2%, ranging from 50% to 60% in most wards. Highest exposure appeared to be among those aged 30–39 and 50–59 years, with women showing greater seropositivity. Seropositivity increased with family size, with only marginal differences among people with varying levels of education. Seroprevalence was significantly lower among smokers. Only 11% of the survey subjects reported any COVID-19 symptoms, while 17% had appeared for COVID-19 testing. Over half the city's population was infected within a year of onset of the pandemic. However, ∼ 46% of people remained susceptible, contributing to subsequent waves of infection.

Introduction: Population level screen and treat approach for anaemia reduction could be beneficial but its feasibility and impact remains to be tested. Methods: This cluster randomised trial in rural Telangana included 14 clusters randomised (1:1) to either intervention or control arms. A cluster included all participants (6 months to 50 years) served by a frontline health worker. In the intervention arm, participants were screened for anaemia at point of care, using WHO 2011 cut-offs, followed by iron–folic acid (IFA) supplementation as per the national guidelines. The control arm participants were eligible for benefits of an ongoing national programme. The primary outcome was mean difference (MD) in haemoglobin between two arms at 6 months. The trial was registered at CTRI (CTRI/2019/01/016918). Results: Baseline characteristics of participants in the intervention (n=6131) and control (n=5255) arms were broadly similar. In the intervention arm, 88.6% of eligible participants were screened and intervention was delivered to 97% of participants. There was no difference in population haemoglobin (g/dL) between the arms (MD 0.03, 95% CI −0.06 to 0.12, p=0.464). However, after adjustment for relevant confounders, mean haemoglobin in the intervention arm was significantly higher (MD 0.25 g /dL, 95% CI 0.03 to 0. 48, p=0.028). Anaemia prevalence was lower in the intervention than the control arm in total sample (29.6% vs 32.5%, p=0.002) as well as in adolescent girls (40.7% vs 56.0%, p<0.001) and women of reproductive age (WRA, 52% vs 56.5%, p=0.02). Compliance to IFA (% consumption of prescribed dose) was 32% and 47.5% in those receiving therapeutic and prophylactic doses, respectively. Conclusion: This study demonstrates the feasibility of implementing a population level screen and treat approach. The intervention reduced anaemia prevalence significantly among vulnerable groups, particularly adolescent girls and WRA. Modest improvement in population haemoglobin and anaemia reduction suggests a need for strategies to improve the compliance to IFA. Trial registration number: CTRI/2019/01/016918.