COVID-19 is a disease caused by the SARS-CoV-2 virus, a member of a large family of viruses that can cause illness in humans and animals. The virus has spread rapidly worldwide, prompting the World Health Organization to declare a COVID-19 pandemic.

The number of reported cases does not reflect the true prevalence of COVID-19 in the population, as it is subject to several limitations. For example, people with more severe symptoms are more likely to be tested. To accurately gauge the magnitude of the problem, we need data from a representative sample of the population, not just the people most likely to test positive for the virus.

The study aims to estimate the percentage of Gauchos infected with COVID-19, assess the spread rate of the infection, provide accurate indicators for lethality calculations, and determine the percentage of asymptomatic or subclinical infections.

It will also collect data on social distancing practices. A total of 36,000 people will be tested and interviewed in eight stages of data collection.

The national study, supported by the Ministry of Health, carried out three phases of testing in 133 Brazilian cities between May 14 and June 24. The next phases are being structured.