PT  - JOURNAL ARTICLE
AU  - Mohamed Bailor Barrie
AU  - Sulaiman Lakoh
AU  - J Daniel Kelly
AU  - Joseph Sam Kanu
AU  - James Sylvester Squire
AU  - Zikan Koroma
AU  - Silleh Bah
AU  - Osman Sankoh
AU  - Abdulai Brima
AU  - Rashid Ansumana
AU  - Sarah A Goldberg
AU  - Smit Chitre
AU  - Chidinma Osuagwu
AU  - Raphael Frankfurter
AU  - Justin Maeda
AU  - Bernard Barekye
AU  - Tamuno-Wari Numbere
AU  - Mohammed Abdulaziz
AU  - Anthony Mounts
AU  - Curtis Blanton
AU  - Tushar Singh
AU  - Mohamed Samai
AU  - Mohamed Vandi
AU  - Eugene T Richardson
TI  - SARS-CoV-2 antibody prevalence in Sierra Leone, March 2021: a cross-sectional, nationally representative, age-stratified serosurvey
AID  - 10.1136/bmjgh-2021-007271
DP  - 2021 Nov 01
TA  - BMJ Global Health
PG  - e007271
VI  - 6
IP  - 11
4099  - http://gh.bmj.com/content/6/11/e007271.short
4100  - http://gh.bmj.com/content/6/11/e007271.full
SO  - BMJ Global Health2021 Nov 01; 6
AB  - Introduction As of 26 March 2021, the Africa Centres for Disease Control and Prevention had reported 4 159 055 cases of COVID-19 and 111 357 deaths among the 55 African Union member states; however, no country has published a nationally representative serosurvey as of October 2021. Such data are vital for understanding the pandemic’s progression on the continent, evaluating containment measures, and policy planning.Methods We conducted a cross-sectional, nationally representative, age-stratified serosurvey in Sierra Leone in March 2021 by randomly selecting 120 Enumeration Areas throughout the country and 10 randomly selected households in each of these. One to two persons per selected household were interviewed to collect information on sociodemographics, symptoms suggestive of COVID-19, exposure history to laboratory-confirmed COVID-19 cases, and history of COVID-19 illness. Capillary blood was collected by fingerstick, and blood samples were tested using the Hangzhou Biotest Biotech RightSign COVID-19 IgG/IgM Rapid Test Cassette. Total seroprevalence was estimated after applying sampling weights.Results The overall weighted seroprevalence was 2.6% (95% CI 1.9% to 3.4%). This was 43 times higher than the reported number of cases. Rural seropositivity was 1.8% (95% CI 1.0% to 2.5%), and urban seropositivity was 4.2% (95% CI 2.6% to 5.7%).Discussion Overall seroprevalence was low compared with countries in Europe and the Americas (suggesting relatively successful containment in Sierra Leone). This has ramifications for the country’s third wave (which started in June 2021), during which the average number of daily reported cases was 87 by the end of the month:this could potentially be on the order of 3700 actual infections per day, calling for stronger containment measures in a country with only 0.2% of people fully vaccinated. It may also reflect significant under-reporting of incidence and mortality across the continent.Data are available upon reasonable request.