ArticleThe Lancet regional health. Western Pacific2021
Low seroprevalence of COVID-19 in Lao PDR, late 2020.
Article in The Lancet regional health. Western Pacific, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 18 papers, 2 of them syntheses that pooled it.
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Who cites it
18 citing papers in PubMed, 2 syntheses or guidelines pooled it, 21 citations in OpenAlex.
- Differential COVID-19 infection rates in children, adults, and elderly: Systematic review and meta-analysis of 38 pre-vaccination national seroprevalence studies.Journal of global health · 2023Pooled it
- Age-stratified infection fatality rate of COVID-19 in the non-elderly population.Environmental research · 2023Pooled it
- Characteristics of COVID-19 cases and factors associated with disease severity in Lao People's Democratic Republic: a nationwide study.BMC infectious diseases · 2026Observational
- Community engagement to support public health: mixed-method evaluation evidence on COVID-19 attitudes and practices in Lao PDR.Global health action · 2025Article
- Influenza and respiratory syncytial virus dynamics in Lao PDR during the COVID-19 pandemic: a hospital-based surveillance study.BMJ open · 2025Article
- Viruses of parasites: A roadmap toward diagnostic and therapeutic development.PLoS neglected tropical diseases · 2025Review
- Article
- Nationwide seroprevalence of SARS-CoV-2 during the COVID-19 pandemic and prepandemic periods in Lao PDR.PloS one · 2025Article
- Hepatitis B Virus Exposure, Seroprotection Status, and Susceptibility in Health Care Workers From Lao People's Democratic Republic: Cross-Sectional Study.JMIR public health and surveillance · 2024Article
- Community engagement and local governance for health equity through trust: lessons from developing the CONNECT Initiative in the Lao People's Democratic Republic.BMJ global health · 2024Article
- Modelling COVID-19 transmission dynamics in Laos under non-pharmaceutical interventions, vaccination, and replacement of SARS-CoV-2 variants.BMC global and public health · 2024Article
- Lao PDR as an emergency preparedness model for developing countries: Lessons learned from the COVID-19 pandemic.Journal of global health · 2023Article
- SARS-CoV-2-related bat virus behavior in human-relevant models sheds light on the origin of COVID-19.EMBO reports · 2023Article
- Genomic epidemiology of SARS-CoV-2 in Cambodia, January 2020 to February 2021.Virus evolution · 2023Article
- A strategy to assess spillover risk of bat SARS-related coronaviruses in Southeast Asia.Nature communications · 2022Article
- Article
- Did Laos really control the transmission of SARS-CoV-2 in 2020?The Lancet regional health. Western Pacific · 2021Article
- The Pandemic Experience in Southeast Asia: Interface Between SARS-CoV-2, Malaria, and Dengue.Frontiers in tropical diseases · 2021Article
Corrections and comments
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Authors and funding
19 authors at 6 institutions in 6 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundIn 2020 Lao PDR had low reported COVID-19 cases but it was unclear whether this masked silent transmission. A seroprevalence study was done August - September 2020 to determine SARS-CoV-2 exposure.
methodsParticipants were from the general community (n=2433) or healthcare workers (n=666) in five provinces and bat/wildlife contacts (n=74) were from Vientiane province. ELISAs detected anti- SARS-CoV-2 Nucleoprotein (N; n=3173 tested) and Spike (S; n=1417 tested) antibodies. Double-positive samples were checked by IgM/IgG rapid tests. Controls were confirmed COVID-19 cases (n=15) and pre-COVID-19 samples (n=265). Seroprevalence for the general community was weighted to account for complex survey sample design, age and sex.
findingsIn pre-COVID-19 samples, 5·3%, [95% CI=3·1-8·7%] were anti-N antibody single-positive and 1·1% [0·3-3·5%] were anti-S antibody single positive. None were double positive. Anti-N and anti-S antibodies were detected in 5·2% [4·2-6·5%] and 2·1% [1·1-3·9%] of the general community, 2·0% [1·1-3·3%] and 1·4% [0·5-3·7%] of healthcare workers and 20·3% [12·6-31·0%] and 6·8% [2·8-15·3%] of bat/wildlife contacts. 0·1% [0·02-0·3%] were double positive for anti-N and anti-S antibodies (rapid test negative).
interpretationWe find no evidence for significant SARS-CoV-2 circulation in Lao PDR before September 2020. This likely results from early decisive measures taken by the government, social behavior, and low population density. High anti-N /low anti-S seroprevalence in bat/wildlife contacts may indicate exposure to cross-reactive animal coronaviruses with threat of emerging novel viruses.
fundingAgence Française de Développement. Additional; Institut Pasteur du Laos, Institute Pasteur, Paris and Luxembourg Ministry of Foreign and European Affairs ("PaReCIDS II").
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Registered trials
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