ArticleInternational journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases2021
Serial population-based serosurveys for COVID-19 in two neighbourhoods of Karachi, Pakistan.
Article in International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 19 papers.
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Who cites it
19 citing papers in PubMed.
- The Impact of the COVID-19 Pandemic on Pregnant Women with Perinatal Anxiety Symptoms in Pakistan: A Qualitative Study.International journal of environmental research and public health · 2021Trial
- Validation of polyester nasal swabs for post-mortem SARS-CoV-2 diagnosis in Karachi, Pakistan: a prospective surveillance analysis.Journal of global health · 2025Observational
- Evidence of rapid rise in population immunity from SARS-CoV-2 subclinical infections through pre-vaccination serial serosurveys in Pakistan.Journal of global health · 2025Article
- Pre-existing IgG antibodies to HCoVs NL63 and OC43 Spike increased during the pandemic and after COVID-19 vaccination.Heliyon · 2025Article
- Secondary attack rates and determinants of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) household transmission in Pakistan: A case-ascertained prospective, longitudinal study.Journal of infection and public health · 2024Article
- Humoral and T cell responses to SARS-CoV-2 reveal insights into immunity during the early pandemic period in Pakistan.BMC infectious diseases · 2023Article
- Investigating the impact of prior COVID-19 on IgG antibody and interferon γ responses after BBIBP-CorV vaccination in a disease endemic population: A prospective observational study.Health science reports · 2023Article
- A neighborhood-level analysis of association between social vulnerability and COVID-19 in ahvaz, Iran.International journal of disaster risk reduction : IJDRR · 2023Article
- Article
- Prevalence and risk factors of Severe Acute Respiratory Syndrome Coronavirus 2 infection in women and children in peri-urban communities in Pakistan: A prospective cohort study.Journal of global health · 2022Article
- Optimizing prevalence estimates for a novel pathogen by reducing uncertainty in test characteristics.Epidemics · 2022Article
- Article
- Performance Evaluation of Lateral Flow Assays for Coronavirus Disease-19 Serology.Clinics in laboratory medicine · 2022Review
- Change in age distribution of COVID-19 deaths with the introduction of COVID-19 vaccination.Environmental research · 2022Article
- IgG antibodies to SARS-CoV-2 in asymptomatic blood donors at two time points in Karachi.PloS one · 2022Article
- A three-phase population based sero-epidemiological study: Assessing the trend in prevalence of SARS-CoV-2 during COVID-19 pandemic in Jordan.One health (Amsterdam, Netherlands) · 2021Article
- Upregulated type I interferon responses in asymptomatic COVID-19 infection are associated with improved clinical outcome.Scientific reports · 2021Article
- COVID-19 vaccination in Sindh Province, Pakistan: A modelling study of health impact and cost-effectiveness.PLoS medicine · 2021Article
- Frequency and Risk Factors for Acute Kidney Injury in patients with COVID-19.Pakistan journal of medical sciencesArticle
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19 authors.
Funding
Abstract
objectiveTo determine population-based estimates of coronavirus disease 2019 (COVID-19) in a densely populated urban community of Karachi, Pakistan.
methodsThree 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.
resultsIn 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.
conclusionContinuing rounds of seroprevalence studies will help to improve understanding of secular trends and the extent of infection during the course of the pandemic.
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