Covid-19 has a new ally in northern Brazil: dengue fever

Earlier this year, the Amazonian state of Acre struggled with a series of calamities. Located on the border with Bolivia and Peru, the region faced skyrocketing Covid-19 numbers, an outbreak of dengue fever, a migrant crisis at the Peruvian border, as well as record-shattering floods.

A recent survey shows that 130,000 people have been affected by the floods, with nearly 1,400 families left homeless. By February, dengue fever cases in 2021 were 574 percent above last year’s levels, and authorities report cases of patients simultaneously contracting dengue fever and Covid-19. 

A study by the University of São Paulo shows that people who have previously contracted dengue fever are twice as likely to develop more severe cases of Covid-19. The study’s findings were published in scientific journal Clinical Infectious Diseases and were the result of blood sample analysis of 1,285 people in Acre state.

“Our results show that populations which are more exposed to dengue fever are also more at risk of becoming ill if infected with the coronavirus,” said researcher Marcelo Urbano Ferreira, speaking to Agência Fapesp.

He explains that this is a syndemia, when two diseases exacerbate each other’s effects. While the coronavirus pandemic has hindered efforts to control dengue fever, the mosquito-borne...