MULTIPLE patients have tested positive for the so-called ‘sloth virus’ in Europe, making it a growing health concern.
The illness was first recognised in 1955 in South America and was detected in Europe for this first time in June this year.
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The officially named Oropouche virus has been observed sporadically in 19 travellers returning from travel – mostly Cuba – in June and July 2024.
On July 25, two women from Brazil, both in their twenties, were the first known cases to die from the virus, according to The Lancet.
Historically, the illness has had a limited circulation in South America.
But it has now been detected in Europe
Here, we look at what sloth virus is…
What is sloth virus?
Sloth virus, or sloth fever, is a Zika-like illness that infects humans through midges.
It appears to be a growing public health concern, however the risk has been classed as moderate, according to Live Science.
The Oropouche virus was first detected in Europe in travellers returning from South America who have been bitten and infected.
Virus symptoms tend to subside within a couple of weeks but one of the main concerns is the potential harmful effects on unborn foetuses.
It’s nickname ‘sloth virus’ came from the pale-throated sloth which is said to be a host for the virus along with non-human primates and birds.
How is Sloth virus spread?
The illness is transmitted from midges after biting an animal with the virus, which carry the disease, and then bite a human who becomes infected.
Luckily the specific carrier of the virus, the Culicoides paraensis midge, is not found in the UK or Europe so warnings are only for travellers and holidaymakers.
Travel Health Consultant at UKHSA Dr Philip Veal 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. 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.”
What are the symptoms of Sloth virus?
Sloth virus or sloth fever symptoms are flu-like.
They start around four to eight days after being bitten and are similar to dengue fever and zika virus.
The common characteristics include muscle aches, eye pain, rashes, eye sensitivity, light sensitivity, vomitting.
In four per cent of cases the nervous system can be infected which leads to an inflammation in areas surrounding the brain and spinal.
The ECDC has stated fatalities are rare and in most cases there is a good recovery rate, around one to two weeks.
Associate Professor Enny Paixao at the London School of Hygiene & Tropical Medicine said the risks to foetal development remain uncertain and require closer scrutiny.
She added: “There is much we still do not know about the Oropouche virus but one of the main concerns arising from the current outbreak in South America is its potential harmful effects on unborn foetuses.”
The predominant risk with sloth virus and expecting mothers is a potential loss of pregnancy and microcephaly, a condition causing the baby’s head to be smaller than average.
Investigators within the WHO suspect cases are contracted by foetus from their mother which leads to poor childbirth outcomes.
Where has Sloth virus been located?
Cases of the vector-borne virus in Europe were tracked back from travellers returning mostly from Cuba.
Outbreaks of Oropouche have been located all over the Americas including Panama, Trinidad and Tobago, French Guiana, Bolivia, Peru, Ecuador, and Colombia.
Until advancements are made in vaccine development or mosquito and midge control… the challenge posed by this neglected tropical disease will persist.
Professor Enny Paixao
First detected in Trinidad and Tobago, 1955, the virus has since spread all over South America and is now reaching Europe.
It’s spread has been put down to climate change, human and animal mobility and behaviour, deforestation, and land use.
How many cases of Sloth virus have there been so far?
In June and July, the 19 cases was reported in three European countries, with twelve cases in Spain, five in Italy, and two in Germany.
These patients had been returning from Cuba or Brazil according to the European Centre for Disease Prevention and Control (ECDC).
According to the Lancet, as of August 1 this year there have been 8,078 confirmed cases of Oropouche in Bolivia, Brazil, Colombia, and Peru.
London School of Hygiene & Tropical Medicine Associate Professor Enny Paixao said there are several factors that may explain the recent outbreak.
These include enhanced surveillance, climate and environment changes, and potential changes to the virus.
She added: “Although Oropouche virus is not new to Brazil, the factors driving the recent sharp increase—including reported deaths and potential foetal harm—highlight the need for further investigation.
“Until advancements are made in vaccine development or mosquito and midge control, or until natural immunity within the population in Brazil increases, the challenge posed by this neglected tropical disease will persist.”
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