Horizon 1 1 17 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES PLoS One e0263127 [12 ] THAILANDE CHIANG MAI PROVINCE LAMPHUN PROVINCE 2022 fdi:010084610 ENG PLoS One 1932-6203 ISI:000775890100049 2 10.1371/journal.pone.0263127 https://www.documentation.ird.fr/hor/fdi:010084610 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/2022-05/010084610.pdf 17 Horizon (IRD) Non-healthcare workers with a high potential for exposure to severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) may contribute to the virus spreading. Data among asymptomatic and high exposure risk populations is still scarce, in particular Chiang Mai and Lamphun provinces, Thailand. We conducted a cross-sectional observational study aiming to assess the prevalence of SARS-CoV-2 RNA positivity, anti-SARS-CoV-2 IgM/IgG, and potential associated factors among asymptomatic/mild symptomatic individuals with a high exposure risk in Chiang Mai and Lamphun provinces, during the second wave of outbreak in Thailand (November 2020-January 2021). Socio-demographic data was collected through an on-line questionnaire prior to collection of nasopharyngeal/throat swab samples and blood samples tested for SARS-CoV-2 RNA (DaAn Gene, China) and anti-SARS-CoV-2 IgM/IgG antibodies (commercial lateral flow immunoassays), respectively. Univariable and multivariable logistic regression analysis were used to analyze associated factors. None of 1,651 participants were found positive for SARS-CoV-2 RNA (0%, 95% confidence intervals, CI: 0-0.2). Fourteen were positive for anti-SARS-CoV-2 IgM/IgG antibodies (0.9%, 95% CI: 0.5-1.4), including 7 positives for IgM and 7 positives for IgG (0.4%, 95% CI: 0.2-0.9). Being over 50 years old was independently associated with virus exposure (OR: 5.8, 95% CI: 1.0-32.1%, p = 0.045). Despite high exposure risk, no current infection was found, and a very high proportion was still susceptible to SARS-CoV-2 infection and would clearly benefit from vaccination. Continuing active surveillance, rolling out of vaccination and monitoring response to vaccine will help better control the COVID-19 spread. 052 ; 050 UR224 / UR174 Thaïlande