4 percent of Brazilians already have Covid-19 antibodies, says study

4 percent of Brazilians already have Covid-19 antibodies, says study
Image: Shutterstock

According to new research by the Health Ministry in partnership with the Brazilian Institute of Geography and Statistics (IBGE), around 4 percent of Brazilians have already developed Covid-19 antibodies — suggesting that a much higher percentage of Brazilians have been infected by the coronavirus than official numbers suggest.

The research was conducted between May 14 and June 24, using three rounds of rapid Covid-19 tests that detect the presence of antibodies in an individual’s bloodstream. Over 89,000 people were tested in 133 cities across all 27 Brazilian states.

The latest round of testing showed that 3.8 percent of volunteers had already developed antibodies. If this holds true for national figures, it could mean that roughly 8 million Brazilians have contracted the virus at some point — significantly larger than the nearly 1.5 million Brazilians that have tested positive so far, according to the Health Ministry.

The study also indicated that 91 percent of participants developed some sort of symptom after being infected. The rapid tests used were provided by Chinese brand Wondfo with a sensibility rate of 85 percent, meaning that there is a 15 percent risk of a “false negative” result.

Underreporting issues

Since the onset of the Covid-19 pandemic, Brazil’s response has been handicapped by chronic underreporting issues. Part of the problem has been the low number of PCR and rapid tests available to the population, often limiting testing only to those patients presenting the most severe symptoms.

Yet, as previously covered by The Brazilian Report, part of the issue stems from the federal government itself, including recent attempts by the Health Ministry to cover up Covid-19 data in a bid to downplay the gravity of the pandemic in Brazil. The lack of transparency brings to mind past cover-ups under the military dictatorship in the 1970s — a grim precedent for the government’s data reliability regarding the pandemic moving forward.

Support this coverage →Support this coverage →