Assessing the burden of Covid-19 in the slums of Bangalore city: Results of Rapid Community Survey

Background: Karnataka, more so Bangalore, reported an increase in number of COVID-19 cases in early April 2021. Objective: To assess the burden of COVID-19 in the slums of Bengaluru city. Materials and Methods: A cross-sectional multi centre community-based study was done in the 2nd and 3rd week of April 2021 in 24 different slums in Bangalore city. WHO cluster random sampling technique was followed. Swabs for RTPCR test and 4 ml of venous blood was collected from 728 subjects more than 18 years of age. Results: A total of 51 (7%) subjects were positive for COVID-19 through RT-PCR. Majority 33 (56.9%) were in the age group of 18-44 years. 148 (20.3%) subjects were sero-positive on blood examination and 18-44 years was the (59.4%) preponderant age group. Overall seropositivity was 20.3% (95%CI; 17.4-23.2) and RT-PCR positivity is 7% (95%CI; 5.2-8.8%) among the subjects surveyed. In the inner core area of Bangalore, seropositivity was 24.2% (95%CI; 21.0 – 27.3) and RT-PCR positivity was 8% (95%CI; 6.1-9.9). Two doses of COVID-19 vaccine were taken only by 1.55% subjects during the study period. Conclusion: The study showed that one in 5 subjects were sero-positive to SARS-CoV-2 and one in 15 individuals had active COVID-19 infection