People who had dengue in the past are twice as likely to develop COVID-19 symptoms, stated a new study published in the journal Clinical Infectious Diseases.
The findings of the study were based on an analysis of blood samples from 1,285 inhabitants of Mâncio Lima, a small town in the state of Acre, part of Brazil's Amazon region. The principal investigator was Marcelo Urbano Ferreira, a professor at the University of São Paulo's Biomedical Sciences Institute (ICB-USP) in Brazil. The study was supported by FAPESP.
“Our results show that the populations most exposed to dengue, possibly owing to socio-demographic factors, are precisely those that most risk falling very sick if they’re infected by SARS-CoV-2. This is an example of what has been called a syndemic [synergic interaction between two epidemic diseases so that one exacerbates the effects of the other]. On one hand, COVID-19 has hindered efforts to control dengue. On the other, the latter appears to increase the risk for those who contract the former,” Ferreira advised Agência FAPESP.
For seven years Ferreira has been conducting analysis in Mncio Lima with the goal of combating malaria. In 2018 he started work on a venture involving a survey of 20% of the city’s inhabitants each six months. His workforce name on houses, apply questionnaires, and acquire blood samples. In early 2020 the venture obtained extra funding from FAPESP in order that a part of the analysis effort may very well be redirected to the monitoring and characterization of SARS-CoV-2 within the area (learn extra at: agencia.fapesp.br/34728).
“In September 2020, a study by another group was published suggesting that areas with many cases of dengue were relatively little affected by COVID-19. Because we already had blood samples collected from inhabitants of Mncio Lima before and after the first wave of the pandemic, we decided to use the material to test the hypothesis that prior infection by dengue virus conferred some degree of protection against SARS-CoV-2. What we found was exactly the opposite,” Ferreira stated.
Methodology
The blood samples analyzed had been collected in November 2019 and November 2020. They had been submitted to checks able to detecting antibodies towards all 4 dengue serotypes and towards SARS-CoV-2.
The outcomes confirmed that 37% of the cohort studied had contracted dengue earlier than November 2019 and 35% had been contaminated by the novel coronavirus earlier than November 2020. Scientific knowledge (signs and outcomes) of the volunteers identified with COVID-19 had been additionally analyzed.
“We deployed statistical analysis to conclude that prior infection by dengue virus doesn’t alter the risk of being infected by SARS-CoV-2. On the other hand, our study also shows that people who have had dengue are more likely to have symptoms if they’re infected by SARS-CoV-2,” stated Vanessa Nicolete, first creator of the article. Nicolete is a researcher with a postdoctoral fellowship at ICB-USP.
The causes of the phenomenon described within the article are unclear. There could also be a organic foundation for it, within the sense that antibodies towards dengue virus one way or the other exacerbate COVID-19, or it could merely be attributable to socio-demographic components that make sure inhabitants teams extra susceptible to each illnesses for numerous causes.
“The results evidence the importance of reinforcing both the social distancing measures introduced to contain the spread of SARS-CoV-2 and efforts to control the dengue vector, as the two epidemics are occurring at the same time and affecting the same vulnerable population. This should be getting more attention from the federal government,” Ferreira stated.
Supply: Eurekalert