key: cord-0733513-s9ml4a92 authors: Halatoko, W. A.; KONU, Y. R.; Gbeasor-Komlanvi, F. A.; Sadio, A. J.; Tchankoni, M. K.; Komlanvi, K. S.; Salou, M.; Dorkenoo, A. M.; Maman, I.; Agbobli, A.; Wateba, M. I.; Adjoh, K. S.; Goeh Akue, E.; Kao, Y.-b.; Kpeto, I.; Pana, P.; Kinde-Sossou, R.; Tamakloe, A.; Nayo-Apetsianyi, J.; Assane, S.-P. H.; Prince-David, M.; Awoussi, S. M.; Djibril, M.; Mijiyawa, M.; Dagnra, A. C.; Ekouevi, D. K. title: Prevalence of SARS-CoV-2 among high-risk populations in Lomé (Togo) in 2020 date: 2020-08-07 journal: nan DOI: 10.1101/2020.08.07.20163840 sha: 48c93d2241b2705530f19ed2e36611669799d0a6 doc_id: 733513 cord_uid: s9ml4a92 Objective: This survey aims at estimating the prevalence of SARS-CoV-2 in high risk populations in Lomé. Methods: From April 23rd to May 8th 2020, we recruited a sample of participants from five sectors: healthcare, air transport, police, road transport and informal. We collected oropharyngeal swab for direct detection through real time reverse transcription polymerase chain reaction (rRT-PCR), and blood for antibodies detection by serological tests. The overall prevalence (current and past) of infection was defined by positivity for both tests. Results: A total of 955 participants with a median age of 36 (IQR 32-43) were included and 71.6% (n=684) were men. Around 22.1% (n=212) were from the air transport sector, 20.5% (n=196) in the police, and 38.7% (n=370) in the health sector. Seven participants (0.7%, 95% CI: 0.3-1.6%) had a positive rRT-PCR at the time of recruitment and nine (0.9%, 95% CI: 0.4-1.8%) were seropositive for IgM or IgG against SARS-CoV-2. We found an overall prevalence of 1.6% (n=15), 95% CI: 0.9-2.6%. Conclusion: The prevalence of the SARS-CoV-2 infection among high-risk populations in Lomé was relatively low and could be explained by the various measures taken by the Togolese government. Therefore, we recommend targeted screening. is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint The copyright holder for this this version posted August 7, 2020. . https://doi.org/10.1101/2020.08.07.20163840 doi: medRxiv preprint Introduction 85 In December 2019, an outbreak of pneumonia (Covid-19) due to a new coronavirus 86 first named 2019-nCoV, now officially SARS-CoV-2, occurred in China [1] . In less than 87 five months, this outbreak had spread rapidly to every continent (except Antarctica) 88 with more than 3.7 million people infected and more than 257,000 deaths recorded as CoV-2 using a rRT-PCR test in order to refine screening strategies in the fight against 122 the pandemic in Togo. is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint The copyright holder for this this version posted August 7, 2020. is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint The copyright holder for this this version posted August 7, 2020. . https://doi.org/10.1101/2020.08.07.20163840 doi: medRxiv preprint Sample size estimation 150 The sample size was estimated using a single proportion population formula with a 151 95% confidence level, 1% margin of error, and 2% estimated prevalence of SARS- 157 We established a test site at the 'Faculté des Sciences de la Santé de l'Université de is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint The copyright holder for this this version posted August 7, 2020. . https://doi.org/10.1101/2020.08.07.20163840 doi: medRxiv preprint is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint The copyright holder for this this version posted August 7, 2020. is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint The copyright holder for this this version posted August 7, 2020. is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint The copyright holder for this this version posted August 7, 2020. Participants came from all the five health districts of the city of Lomé as shown in Figure 257 1. is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint The copyright holder for this this version posted August 7, 2020. Table 3 . is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint The copyright holder for this this version posted August 7, 2020. . https://doi.org/10.1101/2020.08.07.20163840 doi: medRxiv preprint To our knowledge, this is the first study reporting the prevalence of SARS-CoV-2 in is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint The copyright holder for this this version posted August 7, 2020. . https://doi.org/10.1101/2020.08.07.20163840 doi: medRxiv preprint a survey conducted in Iceland, 1,221 (13.3%) of the 9,199 people who were recruited 314 using the symptom-targeted method were positive for SARS-CoV-2 infection [11] . to underestimate the prevalence reported in our population. This prevalence could be 334 multiplied by two or three according to available data but remain less than 3%. is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint The copyright holder for this this version posted August 7, 2020. . https://doi.org/10.1101/2020.08.07.20163840 doi: medRxiv preprint to choose. Also, unavailability of nasopharyngeal swabs didn't allow us to collect both 337 specimens. This study targeted people considered at high risk for Covid-19 based on professional 353 activity as recently recommended by the Swiss National Covid-19 Science Task Force. The WHO also recommends to conduct survey to estimate the prevalence of SARS- is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint The copyright holder for this this version posted August 7, 2020. . https://doi.org/10.1101/2020.08.07.20163840 doi: medRxiv preprint exclude selection bias in our sample due to the recruitment methods. Based on the low 362 prevalence, we did not study the association between prevalence of SARS-CoV-2 363 according to the different sectors. Finally, this study was conducted only in Lomé, is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint The copyright holder for this this version posted August 7, 2020. We are thankful to the participants who accepted to participate in this study and the 386 medical students of the 'Faculté des Sciences de la Santé-Université de Lomé' who 387 performed data collection for the study. 388 We hereby also acknowledge the work of the teams of the two laboratories involved in 389 this study, the members of sectorial unit of management of pandemic in the 'Ministère is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint The copyright holder for this this version posted August 7, 2020. . https://doi.org/10.1101/2020.08.07.20163840 doi: medRxiv preprint laboratory-2020.4-eng.pdf?sequence=1&isAllowed=y. . CC-BY-NC-ND 4.0 International license It is made available under a perpetuity. is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint The copyright holder for this this version posted August 7, 2020. is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint The copyright holder for this this version posted August 7, 2020. is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint The copyright holder for this this version posted August 7, 2020. . https://doi.org/10.1101/2020.08.07.20163840 doi: medRxiv preprint is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint The copyright holder for this this version posted August 7, 2020. is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint The copyright holder for this this version posted August 7, 2020. . https://doi.org/10.1101/2020.08.07.20163840 doi: medRxiv preprint is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint The copyright holder for this this version posted August 7, 2020. . https://doi.org/10.1101/2020.08.07.20163840 doi: medRxiv preprint 2. 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