Canadians flying to popular destinations like Cuba should exercise caution around insects carrying the rare and potentially deadly Oropouche virus, also known as Oropouche fever.
This week, U.S. officials announced 21 cases Oropouche viral disease among travelers returning from Cuba, as of August 16. Most patients recovered without treatment, while three recovered after hospitalization.
The virus is most often spread through the bites of certain species of midges (and mosquitoes) that are not found in Canada.
Doctors are being urged to be on the lookout for infections in returning travelers, however. While Oropouche has previously been detected in Central and South America, as well as the Caribbean, cases this year have been higher than expected, with human infections reported in places where they had not been detected before, including new areas in Brazil, Bolivia and Cuba.
It is unclear what effect the virus has on the health of the fetus, so precautions are advised during pregnancy.
“Historically, it’s been reported as fairly mild, but given some of the emerging data on neurological complications and even mortality — it’s something to watch,” said Dr. Zain Chagla, an infectious disease physician and assistant professor of medicine at McMaster University who is trained in tropical medicine.
“These are areas of the world that Canadians visit even though there is no local distribution [in mosquitoes]“It still means that travellers will need to be assessed for this condition upon return,” Chagla said.
Here’s a look at the disease that prompted the update Canada Travel Health AlertsUSA and Europe.
What is Oropouche virus?
Oropouche virus is endemic, or occurs naturally in tropical forested areas. It was first identified in 1955 on the island of Trinidad and takes its name from a nearby village and wetlands.
It was sometimes called sloth fever, since it was first detected in Brazil in a blood sample taken from an animal.
How does it spread?
Oropouche virus is spread primarily by the bite of a small fly called a midge, often called a “nappy fly,” and also by the bite of some species of mosquito.
“Although the species of midge (Culicoides paraensis) and mosquito (Culex quinquefasciatus) known to transmit Oropouche virus disease are not present in Canada, but have been detected in the United States,” the Public Health Agency of Canada (PHAC) said in response to questions from CBC News.
Scientists say high temperatures, humidity and time of year all affect the midge population.
There have been no documented cases of human-to-human transmission.
What are the symptoms?
Flu-like symptoms resemble those of other tropical diseases such as dengue fever and Zika virus which made headlines in 2015. According to the Pan American Health Organization (PAHO), a major Zika virus outbreak in Brazil has caused an increase in cases of microcephaly, or underdevelopment of the brain, in children.
“It’s a sudden fever, headache that unfortunately is resistant to many treatments, [as well as] “Muscle pain, joint pain,” said Andrea Vicari, head of PAHO’s pandemic preparedness and response unit.
“It can be quite a painful condition, but it usually goes away on its own.”
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Other symptoms, according to the U.S. Centers for Disease Control and Prevention, include sensitivity to light, dizziness, pain behind the eyes, nausea, vomiting and rashes.
Symptoms usually last less than a week, but can often return after a few days or weeks. Most people recover within a few days to a month.
“Oropouche fever can be confused with dengue fever,” notes a Canadian travel health advisory.
How serious is this problem?
According to the CDC, about 60 percent of people infected with Oropouche virus show symptoms.
The US agency estimates that one in 20 patients may develop more serious symptoms, such as bleeding and brain inflammation, such as meningitis and encephalitis.
Insect-borne diseases that infect humans, such as Lyme disease and West Nile virus, are on the rise in Canada. Shorter, less severe winters due to climate change have allowed these insects to expand their range.
In July, Brazilian health authorities reported two deaths in healthy, non-pregnant women infected with the disease.
This World Health Organization reported that these are the first fatal cases of infection in Brazil and the Americas region.
As of July 20, the WHO has recorded more than 8,000 confirmed cases of Oropouche infection this year, including more than 7,200 in Brazil, as well as in Bolivia, Peru, Colombia and Cuba.
Brazilian authorities also reported five cases in pregnant women with evidence that the virus was transmitted to the fetus, resulting in fetal death or abnormalities at delivery, including microcephaly.
“Until more evidence becomes available, pregnant women travelling to affected areas are advised to strictly follow advice on preventing insect bites,” a PHAC spokesman said.
“Pregnant women should discuss the risks of planned travel with their doctor and see a doctor if they do not feel well after traveling.”
How is it treated and how can it be prevented?
There are no vaccines to prevent infection, nor specific medications to alleviate the symptoms of Oropouche virus.
The best way to avoid infection is to not get bitten at all.
To that end, federal officials recommend consulting a doctor or visiting a travel health clinic, preferably at least six weeks before your trip, to get personalized health advice and recommendations.
When traveling, it is recommended to avoid insect bites at all times by following these tips:
- Always use an approved insect repellent (spray) on exposed skin. For best results, read and follow all label instructions.
- Consider limiting outdoor activities when midges and mosquitoes are most active.
- Hide with light-colored, loose-fitting clothing made of tightly woven fabrics such as nylon or polyester. Wear long pants and tucked-in long-sleeved shirts, closed shoes or boots, and a hat.
- Use mosquito nets when sleeping (day and night) outdoors or in buildings that are not completely roofed.
- Consider wearing an approved clothing treated with insecticide.
What’s next?
U.S. and Canadian officials said they are working to enable rapid detection and surveillance of the virus and disease to enable appropriate public health preventive measures.
All suspected Oropouche virus samples from provincial and territorial laboratories will be sent to the PHAC National Microbiology Laboratory in Winnipeg for confirmatory testing.
