Remarkable variability in SARS-CoV-2 antibodies across Brazilian regions: nationwide serological household survey in 27 states

Abstract

Population based data on COVID-19 are essential for guiding policy. We report on the first wave of seroprevalence surveys relying upon on household probabilistic samples of 133 large sentinel cities in Brazil, including 25,025 participants from all 26 states and the Federal District. Seroprevalence of antibodies to SARS-CoV-2, assessed using a lateral flow rapid test, varied markedly across the cities and regions, from below 1% in most cities in the South and Center-West regions to up to 25% in the city of Breves in the Amazon (North) region. Eleven of the 15 cities with the highest seroprevalence were located in the North, including the six cities with highest prevalence which were located along a 2,000 km stretch of the Amazon river. Overall seroprevalence for the 90 cities with sample size of 200 or greater was 1.4% (95% CI 1.3-1.6). Extrapolating this figure to the population of these cities, which represent 25% of the country population, led to an estimate of 760,000 cases, as compared to the 104,782 cases reported in official statistics. Seroprevalence did not vary significantly between infancy and age 79 years, but fell by approximately two-thirds after age 80 years. Prevalence was highest among indigenous people (3.7%) and lowest among whites (0.6%), a difference which was maintained when analyses were restricted to the North region, where most indigenous people live. Our results suggest that pandemic is highly heterogenous, with rapid escalation in the North and Northeast, and slow progression in the South and Center-West regions.

Evidence, rationality, and ignorance: Agnotological issues in COVID-19 science

“…It appears to imply that there was active community transmission in South Brazil in 2019. This conclusion contradicts surveillance data, which point toward the late epidemic peak in the Southern Region of Brazil, as well as the findings of a national seroprevalence survey, which identified few cases in this region 22 . In a country where responses to COVID-19 lead to serious political disputes 23 , a report on the early detection of SARS-CoV-2 positivity in sewage samples cannot be readily translated as evidence of circulation .…”

Susceptibility to SARS-CoV-2 Infection Among Children and Adolescents Compared With Adults

“…A total of 18 studies were contact-tracing studies (CTSs), 7,10,12,16-31 with 3 based in schools, [29][30][31] and 14 studies were population screening studies. 7, [32][33][34][35][36][37][38][39][40][41][42][43][44][45] Two were high quality, 33,35 22 were medium quality, 10,12,16,21,22,[24][25][26][27][29][30][31][32]34,36,38,[40][41][42][43][44][45] 7 were low quality, [17][18][19][20]23,28,39 and 1 was uncertain quality. 7,37…”

“…Data from prevalence studies for children and adolescents compared with adults are shown in Figure 4. 7, [32][33][34][35][36][38][39][40][41][42][43][44][45] We did not undertake a meta-analysis of population screening studies given the important differences in the populations, epidemic time points, and methodologies involved.…”

COVID-19 no Nordeste brasileiro: sucessos e limitações nas respostas dos governos dos estados

“…The Northeast, one of the poorest regions of the country, constitutes 27% of the Brazilian population but has about a third ( 34% ) of all cases and deaths (32%) 1 . A nationwide serological survey showed a remarkable variability in the prevalence of SARS coronavirus-2 antibodies in different Brazilian regions 9 , with extremely high rates in cities in the poorer regions. The new coronavirus pandemic has been a challenge for Brazil due to these deep internal inequalities, known to be associated with the pandemic both nationally and internationally.…”