TY - JOUR
T1 - Population-based surveys of antibodies against SARS-CoV-2 in Southern Brazil
AU - Silveira, Mariângela F.
AU - Barros, Aluísio J.D.
AU - Horta, Bernardo L.
AU - Pellanda, Lúcia C.
AU - Victora, Gabriel D.
AU - Dellagostin, Odir A.
AU - Struchiner, Claudio J.
AU - Burattini, Marcelo N.
AU - Valim, Andréia R.M.
AU - Berlezi, Evelise M.
AU - Mesa, Jeovany M.
AU - Ikeda, Maria Letícia R.
AU - Mesenburg, Marilia A.
AU - Mantesso, Marina
AU - Dall’Agnol, Marinel M.
AU - Bittencourt, Raqueli A.
AU - Hartwig, Fernando P.
AU - Menezes, Ana M.B.
AU - Barros, Fernando C.
AU - Hallal, Pedro C.
AU - Victora, Cesar G.
N1 - Funding Information:
This work was started through the Data Committee created by the State of Rio Grande do Sul government to fight the COVID-19 pandemics. The tests used in the study have been provided by the Brazilian Ministry of Health. Funding for data collection was provided by UNIMED Porto Alegre, Instituto Cultural Floresta and Instituto Serrapilheira.
Publisher Copyright:
© 2020, The Author(s), under exclusive licence to Springer Nature America, Inc.
PY - 2020/8/1
Y1 - 2020/8/1
N2 - Population-based data on COVID-19 are urgently needed. We report on three rounds of probability sample household surveys in the state of Rio Grande do Sul (Brazil), carried out in nine large municipalities using the Wondfo lateral flow point-of-care test for immunoglobulin M and G antibodies against SARS-CoV-2 (https://en.wondfo.com.cn/product/wondfo-sars-cov-2-antibody-test-lateral-flow-method-2/). Before survey use, the assay underwent four validation studies with pooled estimates of sensitivity (84.8%; 95% confidence interval (CI) = 81.4–87.8%) and specificity (99.0%; 95% CI = 97.8–99.7%). We calculated that the seroprevalence was 0.048% (2/4,151; 95% CI = 0.006–0.174) on 11–13 April (round 1), 0.135% (6/4,460; 95% CI = 0.049–0.293%) on 25–27 April (round 2) and 0.222% (10/4,500; 95% CI = 0.107–0.408) on 9–11 May (round 3), with a significant upward trend over the course of the surveys. Of 37 family members of positive individuals, 17 (35%) were also positive. The epidemic is at an early stage in the state, and there is high compliance with social distancing, unlike in other parts of Brazil. Periodic survey rounds will continue to monitor trends until at least the end of September, and our population-based data will inform decisions on preventive policies and health system preparedness at the state level.
AB - Population-based data on COVID-19 are urgently needed. We report on three rounds of probability sample household surveys in the state of Rio Grande do Sul (Brazil), carried out in nine large municipalities using the Wondfo lateral flow point-of-care test for immunoglobulin M and G antibodies against SARS-CoV-2 (https://en.wondfo.com.cn/product/wondfo-sars-cov-2-antibody-test-lateral-flow-method-2/). Before survey use, the assay underwent four validation studies with pooled estimates of sensitivity (84.8%; 95% confidence interval (CI) = 81.4–87.8%) and specificity (99.0%; 95% CI = 97.8–99.7%). We calculated that the seroprevalence was 0.048% (2/4,151; 95% CI = 0.006–0.174) on 11–13 April (round 1), 0.135% (6/4,460; 95% CI = 0.049–0.293%) on 25–27 April (round 2) and 0.222% (10/4,500; 95% CI = 0.107–0.408) on 9–11 May (round 3), with a significant upward trend over the course of the surveys. Of 37 family members of positive individuals, 17 (35%) were also positive. The epidemic is at an early stage in the state, and there is high compliance with social distancing, unlike in other parts of Brazil. Periodic survey rounds will continue to monitor trends until at least the end of September, and our population-based data will inform decisions on preventive policies and health system preparedness at the state level.
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U2 - 10.1038/s41591-020-0992-3
DO - 10.1038/s41591-020-0992-3
M3 - Article
C2 - 32641783
AN - SCOPUS:85087659662
SN - 1078-8956
VL - 26
SP - 1196
EP - 1199
JO - Nature Medicine
JF - Nature Medicine
IS - 8
ER -