TY - JOUR
T1 - Low seroprevalence of COVID-19 in Lao PDR, late 2020
AU - Virachith, Siriphone
AU - Pommelet, Virginie
AU - Calvez, Elodie
AU - Khounvisith, Vilaysone
AU - Sayasone, Somphou
AU - Kounnavong, Sengchanh
AU - Maxay, Mayfong
AU - Xangsayarath, Phonepadith
AU - Temmam, Sarah
AU - Eloit, Marc
AU - Escriou, Nicolas
AU - Rose, Thierry
AU - Vongphayloth, Khamsing
AU - Hübschen, Judith M.
AU - Lacoste, Vincent
AU - Somlor, Somphavanh
AU - Phonekeo, Darouny
AU - Brey, Paul T.
AU - Black, Antony P.
N1 - Funding Information:
We would like to thank the study participants and the students of the Lao Tropical Public Health Institute and Thidachanh Soukhaserm, Namfon Mongkhonsinh, for their help with participant recruitment. Latdavone Khenkha, Bounta Vongphachanh and Nouna Innoula provided technical assistance in the laboratory. The authors thank Marion Gransagne (Global Health Department, Institut Pasteur), St?phane Petres and staff of the Production and Purification of Recombinant Proteins Technological Platform, Institute Pasteur, Paris, for their invaluable help in N and S antigen design and production. Rapid tests were a donation from the European Union. SV coordinated the participant recruitment and laboratory work, wrote the manuscript and verified the underlying data, VP formulated the study design, data analysis plan, wrote the manuscript and verified the underlying data, EC helped with study design and manuscript writing, VK helped coordinate participant recruitment and laboratory analysis, SS, SK, MM and PX helped with study design and manuscript formulation, ST, ME, NE and TR made the recombinant proteins, helped in data analysis and writing the manuscript, KV helped with participant recruitment and study design, JH, VL, SS and DP helped with the study design, data interpretation and writing the manuscript; PTB and APB designed and coordinated the study, interpreted the data and wrote the manuscript. Anonymous participant data will be available upon request to the corresponding author. Requests will be reviewed and approved by the researcher, and staff on the basis of scientific merit and absence of competing interests. Once the request is approved, data can be transferred after the signing of a data access agreement and a confidentiality agreement.
Funding Information:
Role of the funding source The main funding was received from Agence Française de Développement (AFD), with additional support from Institut Pasteur du Laos, Institute Pasteur, Paris and Luxembourg Ministry of Foreign and European Affairs (“PaReCIDS II” grant).
Publisher Copyright:
© 2021
PY - 2021/8
Y1 - 2021/8
N2 - Background: 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. Methods: 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. Findings: 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). Interpretation: 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. Funding: Agence Française de Développement. Additional; Institut Pasteur du Laos, Institute Pasteur, Paris and Luxembourg Ministry of Foreign and European Affairs (“PaReCIDS II”).
AB - Background: 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. Methods: 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. Findings: 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). Interpretation: 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. Funding: Agence Française de Développement. Additional; Institut Pasteur du Laos, Institute Pasteur, Paris and Luxembourg Ministry of Foreign and European Affairs (“PaReCIDS II”).
UR - https://www.scopus.com/pages/publications/85110754765
UR - https://www.ncbi.nlm.nih.gov/pubmed/34278365
U2 - 10.1016/j.lanwpc.2021.100197
DO - 10.1016/j.lanwpc.2021.100197
M3 - Article
C2 - 34278365
AN - SCOPUS:85110754765
SN - 2666-6065
VL - 13
SP - 100197
JO - The Lancet Regional Health - Western Pacific
JF - The Lancet Regional Health - Western Pacific
M1 - 100197
ER -