The Oropouche virus has been a long-standing issue in the Amazon region, causing outbreaks for decades. However, historically, it has not been a major concern for the rest of the world. This, however, seems to be changing. In 2024, the virus demonstrated its ability to travel beyond its usual boundaries.
The majority of this year’s 11,000-plus cases were reported in Brazil and Peru, where the virus is well-known. However, it has also been detected in other countries such as Bolivia, Colombia, Ecuador, Guyana, Panama, and Cuba. This is the first time that Cuba has reported cases of the virus within its borders. Additionally, infected travelers have brought the virus to North America and Europe, with cases being reported in Canada, the United States, Spain, Italy, and Germany.
For experts who study arboviruses like Oropouche, this situation is concerning. Despite having some understanding of its transmission cycle, there is still not enough information to accurately predict how the virus will behave in the future. According to Juan Carlos Navarro, director of research at SEK International University, the puzzle pieces are there, but there is no certainty about the role each one plays.
The first symptoms of Oropouche virus disease typically appear between three and 12 days after being bitten by an infected mosquito. These symptoms can include headaches, muscle and joint pain, chills, nausea, vomiting, and sensitivity to light. In some cases, skin rashes and bleeding from the gums or nose may occur, and in severe cases, meningitis or encephalitis may develop. While the infection is usually uncomplicated, this year, Brazil reported two deaths linked to the virus.
Researchers have noticed a trend in areas where outbreaks have occurred: deforestation. The conversion of natural land for agricultural purposes, resource extraction, and other human activities seems to be a major factor in the emergence and spread of the virus. According to Navarro, this process brings together the three key elements needed for an outbreak: the virus, the vector (mosquitoes), and humans.
The Oropouche virus has a natural cycle that involves nonhuman primates, sloths, rodents, and birds in the jungle. These animals act as reservoirs, keeping the virus circulating even if they do not become ill themselves. Navarro has been studying arboviruses for 30 years, including Oropouche since 2016. He explains that the virus has two transmission cycles, one in the jungle and one in urban areas, where humans are the primary hosts.
In conclusion, the Oropouche virus has been a recurring issue in the Amazon region for decades, but it is now showing signs of spreading beyond its usual boundaries. With limited understanding of its transmission cycle and the impact of human activities such as deforestation, experts are concerned about the potential for future outbreaks. Continued research and monitoring of the virus will be crucial in understanding and controlling its spread.
