The Oropouche virus, also known as “sloth fever,” has recently appeared in three countries in Europe.
Transmitted via midge and some mosquito bites, the vector-borne disease usually gives those affected mild symptoms like headaches, a rash, and a fever.
But the “mysterious” disease can also sometimes cause meningitis and encephalitis, The Lancet writes.
It may affect pregnant women more than others and could cause miscarriage or foetal abnormalities.
This disease was first found in Trinidad and Tobago in 1955. Since then, “sloth fever” has mostly stayed in the forested areas of South America.
“As of Aug 1, 2024, there have been 8,078 confirmed cases of Oropouche fever in the region, reported in Bolivia, Brazil, Colombia, and Peru,” The Lancet says.
The European Centre for Disease Prevention and Control (ECDC) says that “The prognosis for recovery is good and fatal outcomes are extremely rare.”
Additionally, “no secondary transmission has ever been reported,” they add. That’s because, as the Centre for Disease Control (CDC) says, “The virus is not spread from person-to-person through coughing, sneezing, or touching.”
Where has “sloth fever” been found?
It’s mostly in South and Central America. It appeared in Cuba for the first time since the first of August and has since had confirmed cases in Italy, Germany, and Spain.
That’s unusual for the virus. Even though over half a million confirmed cases have been recorded over the last 70 or so years, the disease has historically stayed put in the sam forested areas.
Brazil reported two deaths (of young women, aged 21 and 24, with no comorbidities) from the disease recently.
They experienced severe abdominal pain, bleeding, and hypotension before dying. However, the Centre for Disease Control (CDC) says “Death from Oropouche is rare.”
The ECDC says there is a “moderate... likelihood of infection for EU/EEA citizens travelling to, or residing in epidemic areas in South and Central America.”
They advise those who do travel to those areas to be extremely vigilant about protecting themselves from insect bites by covering their skin, using repellent products, and sleeping under mosquito nets.
Pregnant people in particular should stay abreast of all updates, they say. Some discourage those expecting from visiting epidemic areas at all.
“In June and July 2024, 19 imported cases of Oropouche virus disease were reported for the first time in EU countries: Spain (12), Italy (5), and Germany (2). Eighteen of the cases had a travel history to Cuba and one to Brazil,” the ECDC wrote on the 9th of August.
There have been no confirmed cases in the UK.
How does it spread?
Again, it’s a vector-borne disease, so it spreads through things like midge bites.
It does not spread through things like sneezing or touching an affected person.
The Lancet says, “This increased dissemination, as with other vector-borne disease, is driven by factors like climate change, human and animal mobility and behaviour, deforestation, and land use.”
They add that because the disease has three times as many RNA segments in its genome than most other insect-borne viruses, mutations are more likely.
“These genetic changes can impact the virus’ ability to infect, cause disease, spread, evade the immune system, and develop drug resistance,” the publication reads.
What are the symptoms?
The CDC says “Common symptoms include fever, severe headache, chills, muscle aches, and joint pains.”
These usually start between four to six days after being bitten.
They add that other symptoms can include light sensitivity, stuff joints, dizziness, pain behind the eyes, nausea, vomiting, and a rash.
Symptoms typically last from two days to a week, they say, but can recur in a matter of days or even weeks.
“Some people (fewer than one in 20) will develop more serious disease including meningitis (inflammation of the membranes that surround the brain and spinal cord), encephalitis (inflammation of the brain), or bleeding,” they add.
“Unfortunately, there are no vaccines or specific therapies available or in development,” The Lancet writes, though good insect bite protection can help prevent it.
“Chemical insecticides such as deltamethrin and N, N-Diethyl-meta-toluamide have been demonstrated to be effective” against midges, who are most likely to spread the disease, they say.
Should I be worried about “sloth fever” reaching the UK?
No cases have been confirmed so far in the UK, and the ECDC says “the risk of locally-acquired OROV disease in the EU/EEA is low.”
That’s because, “despite the possible importation of further OROV disease cases, as the competent vectors commonly described in the Americas are absent from continental Europe, and to date, no secondary transmission has ever been reported,” they say.
However, some, like Dr Danny Altmann, Professor of Immunology at Imperial College London, are more concerned.
He told the Telegraph that “We should definitely be worried,” adding, “Things are changing and may become unstoppable.”
Dr Philip Veal, Travel Health Consultant at UKHSA, said, “The midge that carries Oropouche virus is not currently established in Europe. It is typically found in the Americas. There is no evidence that the virus can spread from person to person.”
“When travelling to affected areas, you can avoid the infection, and others such as dengue, Zika and malaria, by preventing insect bites,” he added.
“Use insect repellent, cover exposed skin and sleep under a treated bed net. Plan ahead and visit the TravelHealthPro website to look up your destination and the latest health information and advice, particularly if you are pregnant.”