Low seroprevalence of COVID-19 in Lao PDR, late 2020
<strong>Background<br></strong> In 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. <br><strong> Methods<br></stron...
| Main Authors: | , , , , , , , , , , , , , , , , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
Elsevier
2021
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| _version_ | 1826307574526377984 |
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| author | Virachith, S Pommelet, V Calvez, E Khounvisith, V Sayasone, S Kounnavong, S Maxay, M Xangsayarath, P Temmam, S Eloit, M Escriou, N Rose, T Vongphayloth, K Hübschen, JM Lacoste, V Somlor, S Phonekeo, D Brey, PT Black, AP |
| author_facet | Virachith, S Pommelet, V Calvez, E Khounvisith, V Sayasone, S Kounnavong, S Maxay, M Xangsayarath, P Temmam, S Eloit, M Escriou, N Rose, T Vongphayloth, K Hübschen, JM Lacoste, V Somlor, S Phonekeo, D Brey, PT Black, AP |
| author_sort | Virachith, S |
| collection | OXFORD |
| description | <strong>Background<br></strong>
In 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.
<br><strong>
Methods<br></strong>
Participants 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.
<br><strong>
Findings<br></strong>
In 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).
<br><strong>
Interpretation<br></strong>
We 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.
<br><strong>
Funding<br></strong>
Agence Française de Développement. Additional; Institut Pasteur du Laos, Institute Pasteur, Paris and Luxembourg Ministry of Foreign and European Affairs (“PaReCIDS II”). |
| first_indexed | 2024-03-07T07:05:09Z |
| format | Journal article |
| id | oxford-uuid:b1c0ccc3-8047-4bc6-a1a4-b1984af29d3b |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T07:05:09Z |
| publishDate | 2021 |
| publisher | Elsevier |
| record_format | dspace |
| spelling | oxford-uuid:b1c0ccc3-8047-4bc6-a1a4-b1984af29d3b2022-04-29T12:20:33ZLow seroprevalence of COVID-19 in Lao PDR, late 2020Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:b1c0ccc3-8047-4bc6-a1a4-b1984af29d3bEnglishSymplectic ElementsElsevier2021Virachith, SPommelet, VCalvez, EKhounvisith, VSayasone, SKounnavong, SMaxay, MXangsayarath, PTemmam, SEloit, MEscriou, NRose, TVongphayloth, KHübschen, JMLacoste, VSomlor, SPhonekeo, DBrey, PTBlack, AP<strong>Background<br></strong> In 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. <br><strong> Methods<br></strong> Participants 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. <br><strong> Findings<br></strong> In 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). <br><strong> Interpretation<br></strong> We 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. <br><strong> Funding<br></strong> Agence Française de Développement. Additional; Institut Pasteur du Laos, Institute Pasteur, Paris and Luxembourg Ministry of Foreign and European Affairs (“PaReCIDS II”). |
| spellingShingle | Virachith, S Pommelet, V Calvez, E Khounvisith, V Sayasone, S Kounnavong, S Maxay, M Xangsayarath, P Temmam, S Eloit, M Escriou, N Rose, T Vongphayloth, K Hübschen, JM Lacoste, V Somlor, S Phonekeo, D Brey, PT Black, AP Low seroprevalence of COVID-19 in Lao PDR, late 2020 |
| title | Low seroprevalence of COVID-19 in Lao PDR, late 2020 |
| title_full | Low seroprevalence of COVID-19 in Lao PDR, late 2020 |
| title_fullStr | Low seroprevalence of COVID-19 in Lao PDR, late 2020 |
| title_full_unstemmed | Low seroprevalence of COVID-19 in Lao PDR, late 2020 |
| title_short | Low seroprevalence of COVID-19 in Lao PDR, late 2020 |
| title_sort | low seroprevalence of covid 19 in lao pdr late 2020 |
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