What is Oropouche fever, an infection similar to dengue that has spread to 4 countries in South America?

This year, South America is the epicenter shoots dengue in the world, with more than 5 million people affected. At the same time another one virus causing such a disease was strengthening its influence in 4 countries South America: it’s a fever Oropush.

This is another infection that is transmitted to humans through infected insects, some of them are different types of mosquitoes. Although it differs from dengue fever in the types that can transmit the virus. The latter disease is transmitted by female mosquitoes. Aedes aegypti And Aedes albopictus infected.

In dialogue with Information the president Latin American Society of Travel Medicine, Alfonso Rodriguez-Morales, warned that there is a risk of human cases of Oropouche fever emerging in countries such as Argentina. “This is possible because there are also vectors there, infected people can come and there can be transmission,” he said.

The expert added: “Argentina, Ecuador and Venezuela must be prepared for the risk of people from Oropush entering their territories. In fact, Ecuador and Venezuela have had cases in the past.”

In the wild cycle, the Oropush virus has several insect vectors: Culicoides paraensis, Coquilletidia venezuelenzis. And Aedes serratus. In the urban cycle, the vectors are Culicoides paraensis And Culex quinquefasciatusboth are very common in tropical environments, as reported last January Pan American Association of Infectious Diseases.

“In colloquial speech we say that Oropush vectors are mosquitoes. Although from a taxonomic point of view some insects are not mosquitoesHow Culicoides paraensis“, said Information Rodriguez-Morales, who co-authored the January publication.

“IN Argentina, so far there have not been a single case of human infection with Oropush. But we must take into account that our territory is also inhabited by species of insects that can transmit the Oropush virus,” he explained. Infobae Fabricio Tejerinabiologist and director of vector surveillance and control in the municipality HotelsV Missions. “More resources should be invested in surveillance of the Oropouche virus so that we are not surprised later, as happened with dengue,” he said.

Meanwhile, Doctor of Biological Sciences and specialist Mario Linaresfrom the Institute of High Altitude Biology of the National University. Jujuyin Argentina, commented: “As with all diseases transmitted arthropods, there is a risk of transmission while the vector is present in a certain area. If the virus is circulating in neighboring countries, it is possible that someone will come into the country and bring the disease and an outbreak will occur.”

“Insects Aedes serratus And Culex quinquefasciatus They are widespread in Argentina,” said Dr. Linares.

The name of the virus comes from the city Vegas Oropushwhich is located on the island Trinidad and Tobago. There pathogen It was discovered in 1955 in a patient with fever and in mosquitoes.

During 2024 Bolivia, Brazil, Colombia and Peru. reported an increase in the number of confirmed cases, according to PAHO. Brazil has 3,475 cases. This figure is 4 times higher than the same period last year.

Given the spread of the infection, the health agency carried out a rapid risk assessment in February last year. It was believed that the risk of spreading the Oropush virus is “moderate”

for the Americas region.

Since the virus was discovered in Trinidad and Tobago in 1955, cases and outbreaks have been reported in Brazil, Colombia, Ecuador, French Guiana, Panama, Peru, Trinidad and Tobago and Venezuela. Reported outbreaks have occurred primarily in the Amazon region.

According to experts from OPSSince the symptoms of Oropouche fever are similar to those of other arbovirus infections, “it is possible that there is underestimation true burden of disease” in the region.

Outbreaks were usually identified through retrospective population-based or laboratory epidemiological studies.

The increase in the number of Oropush cases in South America is due to various factors. Some of these involve the growing risk of mosquitoes serving as vectors. One of them is changing of the climate which increases rainfall and temperature.

Other factors are deforestation due to the expansion of agricultural boundaries in the area of ​​influence of the Amazon basin and increased urbanization. These situations create a favorable environment for interaction between mosquitoes and humans, and as a result, there is the possibility of increased transmission of the Oropush virus.

“Fragile health systems coupled with political and financial instability in countries facing complex humanitarian crises and high population migration are also determining factors to consider in the face of greater risk of disease spread,” PAHO experts noted.

Symptoms of Oropouche fever are similar to those of dengue fever: sudden onset of high fever, headaches, myalgia, arthralgia and vomiting.), and the incubation period ranges from 4 to 8 days.

Most people with Oropouche fever have mild to moderate symptoms. Cases tend to be self-limiting, with recovery usually occurring within 7 days.

“Complications are rare, although aseptic meningitis can sometimes develop. There is no evidence of human-to-human transmission of the virus,” they said. According to the health agency, no deaths from Oropush have been reported to date.

Six of the state’s nine departments reported 1,014 suspected Oropouche cases, according to the latest PAHO data update. Boliviaof which 160 were confirmed during 2024.

IN Brazil, over a 14-week period this year, the virus was detected in samples from 3,475 patients. They are mostly from the state of Amazonas, but there have also been more than 50 cases in Bahia, in northeastern Brazil.

Bye, Colombia reported two positive cases of Oropos disease identified in samples from the departments of Amazonas and Meta, out of 187 samples collected in 2024 from across the country. The samples were obtained as part of a retrospective laboratory case-finding strategy implemented by the Colombian National Institute of Health (INS) based on dengue surveillance.

IN Peru225 confirmed cases of Oropouche were reported in four departments during the first 15 weeks of the year. This is the highest number of cases reported in this country to date. Confirmed cases have been reported in the following departments: Loreto, Ucayali, Madre de Dios and Huanuco.