A study published this May in the journal Clinical infectious diseases It has been suggested that people with dengue in the past are twice as likely to develop COVID-19 symptoms as hepatitis C virus.
The study was based on the analysis of blood samples from 1,285 people in the small town of Manichi Lima, Acro State, in the Amazon region of Brazil. The chief investigator was Marcelo Urbano Ferrera, a professor at the Institute of Biomedical Sciences (ICB-USP) in São Paulo, Brazil. The study was supported by FAPESP.
Our results show that people who are at risk for dengue are more likely to get sick if they are infected with SARS-CoV-2, perhaps for socioeconomic reasons. This is an example of something called syndicate [ synergic interaction between two epidemic diseases so that one exacerbates the effects of the other ]. On the one hand, COVID-19 inhibits efforts to control dengue. On the other hand, it seems to increase the risk for contractors, ”Ferrera told Agência FAPESP.
Ferrera has been researching in Malachi Lima for seven years to fight malaria. In 2018, every six months, a project that includes a survey of 20% of the city’s population began. His team calls homes, conducts inquiries, and collects blood samples. In early 2020, the project received additional funding from the FAPESP and was part of the research work transferred to SARS-CoV-2 in the region.
"In September 2020, a study by another team found that areas with high levels of dengue were relatively slightly affected by COVID-19. Since we had blood samples collected from the people of Mancio Lima before and after the first outbreak, we decided to use the device to test the level of protection against SARS-CoV-2 in the past. We found exactly the opposite.
Professor Marcelo Urbano Ferrara, Professor of Biomedical Sciences, São Paulo, Brazil
The study was supported by FAPESP.
The blood samples analyzed November 2019 and They met in November 2020. In all four cases of dengue serotypes and SARS-CoV-2, antibodies were presented.
The results show that 37% of the selected group members They were infected with dengue before November 2019, and before November 2020, 35% were infected with the coronavirus. We also analyzed the clinical data (symptoms and outcomes) of COVID-19 volunteers.
We conducted statistical analysis to conclude that the dengue virus did not alter the risk of SARS-CoV-2 infection in the past. On the other hand, our study also shows that people with dengue are more likely to develop symptoms of SARS-CoV-2, says Vanessa Nicolete, the first author of the article. Nicolet is a researcher at the ICB-USP Postgraduate Union.
The reasons for the incident described in the article are not clear. Antibodies to the dengue virus in some way aggravate COVID-19, or there may be only biological factors that make certain sections of the population vulnerable to both diseases for a variety of reasons.
The results confirm the need to strengthen social distance measures to control the spread of SARS-CoV-2 and dengue vectors while simultaneously affecting both epidemics and affecting the same vulnerable population. This needs to be given more attention than the federal government, Ferrera said.
São Paulo State Research Support Foundation
Nicolet, VC, Inter alia. (2021) Epidemiology in the Amazon of Brazil: In a population-based cohort study, the risk of COVID-19 was associated with previous dengue fever.. Clinical Infectious Disease. Doy