26% of the residents of the city of SP have already had contact with the coronavirus, research points | Saint Paul

The data are part of the fourth stage of a study by Grupo Fleury, Instituto Semeia, IBOPE Inteligência e Todos pela Saúde.

• 21.6% in the richest districts
• 30.4% in the poorest

Prevalence by educational level

• 35.8% of those infected have primary education
• 16% of those infected have higher education

The research analyzed 1,129 blood samples from adults residing in the capital of São Paulo distributed in 152 census tracts between October 1 and 10, 2020.

To analyze the results, the study considered three socioeconomic strata (highest income, intermediate income and lowest income).

The data shows an increase in prevalence when income, education and race are considered.

According to the study, seroprevalence, that is, the frequency of individuals with antibodies against the new coronavirus in the city of São Paulo, was 21.6% in the richest districts and of 30.4% in the poorest.

The survey also identified that contact with the coronavirus was inversely proportional to educational level, with people with primary education (35.8%) having 2.2 times more contact with the coronavirus than those with higher education (16%).

The study also concluded that the frequency of people with antibodies against the coronavirus is higher among blacks and brown people (31.6%) than among whites (20.9%).

The mapping is also carried out by the City of São Paulo. The municipal management data, however, point to lower percentages.

In the city council survey, the phase in which Covid-19 antibodies peaked was identified in the fifth stage, which ended on August 27, when the municipal administration reported that 13.9% of residents had had contact SARS-CoV-2.

In the last phase, in which until September 24 was considered, the percentage was 13.6%.

The results obtained on Monday (10) are part of the fourth phase of the study that seeks to map Covid-19 in the city of São Paulo, the project will have six stages and in each of them samples of around 1,160 people will be taken, distributed to through the capital of São Paulo.

In the third stage, the researchers included a new type of test to verify the presence of antibodies against SARS-CoV-2 in the samples.

The inclusion of a new type of test helped to more accurately detect the presence of antibodies in the collected samples. Now, in addition to the chemiluminescence test to detect IgG and IgM separately, the electrochemiluminescence test has been added to identify total antibodies.

In phase 2 of the survey, presented in early July, it was found that at least 11.4% of the population had had contact with the virus, using only the same type of test, the result of the study presented in this second (10) was 11.5%. With the inclusion of the new serological test in the analysis of the samples, the percentage of people over 18 years of age who have had contact with SARS-CoV-2 in the capital of São Paulo rose to 17.9%, a figure equivalent to 1, 5 million. people. The difference between phases 3 and 4 was 8.3 percentage points, since the prevalence went from 17.9% to 26.2%.

The research participants were chosen by lottery. According to Fleury’s clinical director and one of the research coordinators, Celso Granato, the reason is to ensure that the research presents a result closer to reality.

“IBGE [Instituto Brasileiro de Geografia e Estatística] we divide the city into census tracts and then we do a lottery, we choose a part of these census tracts, then within each census tract we do a lottery to choose which house we go to and then within each house Draw the person who will be invited to participate . This is because we want to have a show that is totally random, totally random and we believe that this way we have a representation that is closer to reality, ”Granato said in an interview with G1 in June.

At the beginning of July, the researchers released the first stage of the project, which showed that the percentage of people who were infected with the coronavirus reaches 2.5 times more in the poor neighborhoods of the city of São Paulo compared to the most rich.

According to the survey, the percentage of people who had contact with SARS-CoV-2 in the richest districts was 6.5%, while in the poorest the rate was 16%. In total, 1,183 samples of people over 18 years of age were collected in the 96 districts of São Paulo between June 15 and 24.

Even so, according to the study, the percentage of people who had contact with SARS-CoV-2 in the city of São Paulo was 11.4%. The survey also noted that seroprevalence was 2.5 times higher in black adults than in whites (19.7% vs. 7.9%). Households with 5 or more people had seroprevalence almost twice as high compared to households with only one or two residents (15.8% vs. 8.1%).

In May, specialists from USP, Grupo Fleury, Instituto Semeia and IBOPE Inteligência carried out a pilot project that evaluated 520 inhabitants of six neighborhoods in the capital of São Paulo, considered to have the highest number of cases and deaths per 100,000 inhabitants and concluded that the number de The infected people in the city of São Paulo could be up to 12 times greater than those officially released. The percentage of people who had had contact with the coronavirus was 5.19%.

Fleury’s clinical director and one of the research coordinators, Celso Granato, says that the pilot project carried out in May helped to structure the research that is being carried out, which will last longer and reach a greater number of people.

“We realized, for example, that people are afraid. São Paulo is a dangerous city, so you knock on someone’s door saying ‘look, I came here to collect your blood to do an investigation’, it is something that scares a bit of people, even more so in times of pandemic, so we reconsidered, we learned and now we are starting this new stage “, says Celso in an interview with G1.

The tests used by the researchers are serological, that is, they detect the presence of IgM (Immunoglobin M) and IgG (Immunoglobin G) antibodies, which fight Covid-19 in the body. According to experts, the test detects the presence of IgM in the patient’s blood, at least from the seventh day of the onset of clinical manifestations and IgG from the tenth day.