
A new study in The Lancet Infectious Diseases shows the Oropouche virus may be more widespread in Latin America than previously thought, and as many as 1 in 10 people living in the region have likely experienced a prior infection with the pathogen.
First identified in the 1950s, the virus causes nonspecific symptoms that are usually mild, including fever, chills, headache, pain in the limbs and, in some cases, nausea and skin rashes. The virus is mainly spread by biting midges and possibly some Culex mosquitoes.
But since a large outbreak began in 2023, more case reports of severe complications of infection in pregnant women and at least two deaths have been reported among more than 20,000 cases seen in Latin and Caribbean countries.
Climate, rain behind uptick
To understand the shift, researchers from Berlin’s Charite Hospital analyzed more than 9,400 blood samples collected from healthy and sick people in Bolivia, Brazil, Colombia, Costa Rica, Ecuador and Peru between 2001 and 2022. Antibodies against the virus were present in 6.3% of the samples. Samples taken from people living in the Amazon region showed a 10% prevalence of antibodies, while only 2% of samples from Costa Rica showed antibodies.
Moreover, rain and weather patterns had a direct influence on the number of Oropoche virus infections, suggesting it was climate and environment — and not viral changes — fueling the current outbreak.
We therefore assume that the current Oropouche outbreak has been fueled by weather phenomenons like El Niño.
“We therefore assume that the current Oropouche outbreak has been fueled by weather phenomenons like El Niño,” said Jan Felix Drexler, PhD, head of the virus epidemiology laboratory at Charite said in a press release from Charite. "By contrast, we have not found evidence that changing properties of the virus could provide an alternative explanation for the high case count at present. I think it’s possible that Oropouche virus will become even more widespread in the future as climate change progresses.”