The United States public health agency CDC has issued a health alert due to the increased risk of the oropouche virus for travelers in the Americas, particularly those visiting the Amazon basin and areas of South America and the Caribbean.
Endemic to the Amazon, Oropouche is a virus transmitted by the bite of small flies and mosquitoes that can cause fever, headaches and other ailments.
The disease has recently been detected in Brazil, Bolivia, Peru, Colombia and Cuba, even in areas where it had never been seen before. More than 8,000 cases have been reported between January and August, according to the CDC, including two fatalities. There were also five cases where the virus was transmitted from mother to fetus in which fetal deaths or congenital abnormalities were reported.
This month, the World Health Organization and its regional office, the Pan American Health Organization, urged countries in the Americas to step up surveillance for the disease. It’s a difficult task, since oropouche is often confused with dengue, another virus that has seen record levels this year in the Americas.
Both oropouche and dengue cause high fever, muscle and joint pain, nausea, vomiting and headache, and the best way to distinguish between them is through diagnostic tools. Oropouche causes symptoms in about six out of 10 people who become infected, and there are no vaccines or specific treatments for the disease.
According to the CDC, it is not yet clear what puts some people at risk for more serious health complications. Health authorities around the world are currently investigating the risk to pregnant women.
This year, American and European travelers returning from Cuba and Brazil have contracted oropouche. The U.S. public health agency now advises that travelers who show symptoms consistent with the disease be evaluated and tested for the virus.
The CDC is warning of the need to take steps to prevent the possible importation of the virus into the United States, where there is no current evidence of local transmission, Bloomberg reported.
Oropouche fever, a viral disease that is still little known
Two people died in Brazil in late July from oropouche fever, the first deaths in the world attributed to this disease caused by a little-known virus spread by the bites of infected midges and mosquitoes.
This is what is known so far about this arbovirus, a type of virus transmitted to humans by certain insects.
What happened in Brazil?
Two women from the state of Bahia in northeastern Brazil, “under 30 years old, with no comorbidities” but with “symptoms similar to a severe form of dengue,” have succumbed to oropouche fever, according to the Brazilian Ministry of Health.
“So far, no deaths related to the disease have been reported in the world scientific literature,” Brazilian authorities said, referring also to investigations into another death possibly related to the fever in the south of the country.
Where and how does this virus circulate?
First detected in the archipelago of Trinidad and Tobago in 1955, this arbovirus is primarily transmitted to humans through the bites of midges, but can also be spread by mosquitoes.
“According to our current knowledge, the virus is not transmitted directly from man to man,” Italian infectious disease specialist Concetta Castilletti told AFP.
Brazilian health authorities are also examining six possible cases of transmission of the disease from pregnant women to their children.
So far, oropouche fever has been detected mainly in areas of South America, Central America and the Caribbean.
The first deaths announced by Brazil coincide with a serious dengue epidemic that has already caused thousands of deaths.
Earlier this year, two cases of oropouche fever were identified for the first time in Europe in two unrelated people who returned to Italy after a trip to Cuba, according to Concetta Castilletti.
What symptoms and what treatments?
The virus causes symptoms similar to those of dengue: fever, muscle pain, joint stiffness, headache, vomiting, nausea, chills or sensitivity to light.
Severe forms can lead to life-threatening complications such as meningitis. There are no specific treatments or vaccines.
In affected regions, the best protection is to avoid mosquito and gnat bites by covering your legs and arms, using repellents and fine mesh mosquito nets.according to PAHO.
A threat to the future?
Compared to other arboviruses in its family, such as dengue and chikungunya, oropouche fever has not been widely studied and many questions remain about it, starting with the exact number of confirmed cases.
Furthermore, it is difficult to distinguish from dengue and, among other things, the transmission cycle between animals and humans and complicating factors are unknown.
It is a classic example of a “neglected” disease, according to an article published in the journal Lancet Infectious Diseases.
The virus “has the potential to become a significant threat” given its presence in different environments, the number of species that can transmit it and the risk of serious complications, according to the authors of the article.
According to Concetta Castilletti, regional, national and international authorities need to communicate more and prepare for possible epidemics.
“We must expect the unexpected, as the Covid-19 pandemic should have taught us,” says the Italian scientist.
In recent years, experts have also warned about the impact of global warming, which increases the presence of mosquitoes in many regions of the world and thus increases the risk of the spread of diseases such as dengue and oropouche fever.
