ABSTRACT
OBJECTIVE: To determine population-based estimates of coronavirus disease 2019 (COVID-19) in a densely populated urban community of Karachi, Pakistan. METHODS: Three cross-sectional surveys were conducted in April, June and August 2020 in low- and high-transmission neighbourhoods. Participants were selected at random to provide blood for Elecsys immunoassay for detection of anti-severe acute respiratory syndrome coronavirus-2 antibodies. A Bayesian regression model was used to estimate seroprevalence after adjusting for the demographic characteristics of each district. RESULTS: In total, 3005 participants from 623 households were enrolled in this study. In Phase 2, adjusted seroprevalence was estimated as 8.7% [95% confidence interval (CI) 5.1-13.1] and 15.1% (95% CI 9.4-21.7) in low- and high-transmission areas, respectively, compared with 0.2% (95% CI 0-0.7) and 0.4% (95% CI 0-1.3) in Phase 1. In Phase 3, it was 12.8% (95% CI 8.3-17.7) and 21.5% (95% CI 15.6-28) in low- and high-transmission areas, respectively. The conditional risk of infection was 0.31 (95% CI 0.16-0.47) and 0.41 (95% CI 0.28-0.52) in low- and high-transmission neighbourhoods, respectively, in Phase 2. Similar trends were observed in Phase 3. Only 5.4% of participants who tested positive for COVID-19 were symptomatic. The infection fatality rate was 1.66%, 0.37% and 0.26% in Phases 1, 2 and 3, respectively. CONCLUSION: Continuing rounds of seroprevalence studies will help to improve understanding of secular trends and the extent of infection during the course of the pandemic.
Subject(s)
COVID-19 Serological Testing , COVID-19/diagnosis , COVID-19/epidemiology , Adolescent , Adult , Antibodies, Viral , Bayes Theorem , Child , Child, Preschool , Cross-Sectional Studies , Female , Humans , Immunoassay , Infant , Male , Middle Aged , Pakistan/epidemiology , SARS-CoV-2/immunology , Seroepidemiologic Studies , Urban PopulationABSTRACT
Background Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread to almost every country on the globe, and each country is reporting the symptomatic presentation of their patients to give better insight into the various clinical presentations of SARS-CoV-2. However, the epidemiological literature from Pakistan is scanty. Methods We retrospectively analyzed data from 412 patients who were residents of East Karachi and tested positive for SARS-CoV-2 between February 26 to April 24, 2020. Patients' demographics, symptoms, travel and contact history, and outcomes were recorded. All statistical analysis was performed using the Statistical Package for the Social Sciences (SPSS) version 22 (IBM SPSS Statistics for Windows, IBM Corp, Armonk, NY). Results Most of the patients were male (64.6%), the majority (43.3%) belonging to the 21- to 40-year age group. Most of the patients (65.5%) were residents of Gulshan Iqbal. A total of 15.8% of the patients were admitted to the hospital, and 3.9% of patients expired. The three most common presenting symptoms were fever (74.8%), cough (60.4%), and flu (35.5%). The majority of patients (89.3%) gave a history of contact with SARS-CoV-2 patients. Conclusion The number of SARS-CoV-2 cases is rapidly increasing in Karachi, Pakistan. There is a need to educate the population about the most common sign and symptoms of the virus so that individuals can identify these symptoms and get themselves tested. The concerned authorities should devise an adequate and effective plan to flatten the infectivity curve.