Population-based seroprevalence of SARS-CoV-2 and the herd immunity threshold in Maranhão
Rev. saúde pública (Online)
;
54: 131, 2020. tab, graf
Article
in English
| LILACS, BBO, SES-SP
| ID: biblio-1145072
ABSTRACT
ABSTRACT OBJECTIVE:
To estimate the seroprevalence of SARS-CoV-2 in the state of Maranhão, Brazil.METHODS:
A population-based household survey was performed, from July 27, 2020 to August 8, 2020. The estimates considered clustering, stratification and non-response. Qualitative detection of IgM and IgG antibodies was performed in a fully-automated Elecsys® Anti-SARS-CoV-2 electrochemiluminescence immunoassay on the Cobas® e601 analyzer (Roche Diagnostics).RESULTS:
In total, 3,156 individuals were interviewed. Seroprevalence of total antibodies against SARS-CoV-2 was 40.4% (95%CI 35.6-45.3). Population adherence to non-pharmaceutical interventions was higher at the beginning of the pandemic than in the last month. SARS-CoV-2 infection rates were significantly lower among mask wearers and among those who maintained social and physical distancing in the last month compared to their counterparts. Among the infected, 26.0% were asymptomatic. The infection fatality rate (IFR) was 0.14%, higher for men and older adults. The IFR based on excess deaths was 0.28%. The ratio of estimated infections to reported cases was 22.2.CONCLUSIONS:
To the best of our knowledge, the seroprevalence of SARS-CoV-2 estimated in this population-based survey is one of the highest reported. The local herd immunity threshold may have been reached or might be reached soon.
Full text:
Available
Index:
LILACS (Americas)
Main subject:
Seroepidemiologic Studies
/
Immunity, Herd
/
COVID-19
/
Antibodies, Viral
Type of study:
Qualitative research
Limits:
Adolescent
/
Adult
/
Aged
/
Child
/
Child, preschool
/
Female
/
Humans
/
Infant
/
Male
/
Infant, Newborn
Country/Region as subject:
South America
/
Brazil
Language:
English
Journal:
Rev. saúde pública (Online)
Year:
2020
Type:
Article
Institution/Affiliation country:
Laboratório Central do Maranhão/BR
/
Saúde do Estado do Maranhão/BR
/
Universidade Federal do Maranhão/BR
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