A study by the Portuguese Medical Association (OM) released this Friday concludes that the prevalence rate of the new coronavirus was 3.1% in a sample of 1802 health professionals across the country.
The study aimed to assess whether the health professionals in this sample were infected with covid-19, but remained asymptomatic. The analysis, which began in June, did not include doctors, nurses, medical assistants and other professionals who tested positive for covid-19, nor those who performed functions through teleconsultation, favoring those who were in the field during the critical period of pandemic.
“We still cannot compare seroprevalence in professionals with seroprevalence in the general population,” said OM chairman Miguel Guimarães, who was speaking to journalists in Porto, alongside the promoters of the study, carried out by the Vox Populi Foundation, Fundação Manuel Viegas Guerreiro, The Claude and Sofia Marion Foundation, Álvaro Carvalho Foundation and Germano de Sousa Laboratory Medicine Center.
Safeguarding that the data “are still preliminary”, the study’s coordinator and president of the Álvaro Carvalho Foundation explained that “the objective was to understand if the prevalence rate in health professionals is higher than that of the general population” and, thus, “ know the real impact of the pandemic in Portugal, preparing the country for the coming months ”.
“It was concluded that the prevalence rate was around 3%, which is low for our expectation given the exposure they had. But correction factors must be taken into account. The prevalence rate will be higher in reality ”, said Álvaro Carvalho, internal medicine doctor.
The study aimed at health professionals from primary care units, as well as from the hospital, private, public and social sector institutions. Without needing numbers by professional category, the promoters of the study guaranteed that there was “the concern of being proportional to reality”, that is, more nurses than doctors, for example.
Underlining the coverage from North to South of the country, it was highlighted that the prevalence rate was 6.2% among health professionals in the North region, while in the South the figure is around 2%. The data presented this Friday also point out that about 80% of the interviewed professionals say they worked protected, while 17% answered that they were partially protected and “a small fraction had no protection”.
“This reinforces the problem of this pandemic, which is asymptomatic. About 3% of health professionals became infected and their infection was asymptomatic. They didn’t even notice it ”, analyzed Francisco Antunes, who was director of the infectious disease service at Hospital de Santa Maria and is a retired professor at the Faculty of Medicine of the University of Lisbon.
“It is important to insist that the problem of controlling this infection is the high prevalence of asymptomatic patients. They are transmitters of infection, although certainly in health care they and their patients are protected. We must reinforce the importance of protection ”, concluded Francisco Antunes.
Miguel Guimarães, using specific responses from doctors about personal protective equipment (PPE), also pointed out that “two thirds said they had access [a equipamento], which means that “at least one third will not have had”. “There were some flaws that have to do with different situations and [os profissionais de saúde] they were not always with the PPE they should have. PPE is not the same in all circumstances. A surgical mask is different from an FFP2 ”, he exemplified.
In parallel with this study, there is an analysis and conclusion of two others carried out by the same group of entities. One of them uses the municipality of Vila Nova de Gaia, in the district of Porto, as a “sample municipality” and aims to analyze the epidemiological prevalence rate in Portugal. It includes 3000 people from all parishes and of various age groups.
“Gaia because it is the second largest municipality in the country in terms of number of inhabitants, has an urban and rural area, primary, secondary and tertiary economic activity and was an area very hit by the pandemic at an early stage”, justified Álvaro Carvalho.
The third study, which is entitled “Immune Surveillance Panel” and includes people who tested positive for the new coronavirus, aims to study whether people are left with any humoral immunity and for how long. This panel covers 600 people from all over the country, 200 of whom are professionals and home users, and will take into account four blood tests. The final results will be published with the support of the Public Health Institute of the University of Porto and the Medical School of the Universidade Nova de Lisboa.