The oropouche virus (OROV), an RNA arbovirus, was first detected in the village of Oropouche in Trin (Image: Alamy/PA)
A warning has been issued following a surge in reported cases of the oropouche virus, also known as ‘sloth fever’, in five countries. The European Centre for Disease Prevention and Control has raised concerns after discovering 19 imported cases of the disease within the European Union for the first time.
The oropouche virus (OROV), an RNA arbovirus, was initially identified in the village of Oropouche in Trinidad and Tobago back in 1955. According to the London School of Hygiene and Tropical Medicine, it primarily spreads to humans through the bite of infected biting midges, although some mosquitoes are also known carriers of the virus.
In July, the Pan American Health Organisation (PAHO) issued an epidemiological alert about a rise in reported cases of the virus in five countries – Brazil, Bolivia, Peru, Cuba and Colombia.
Why is it referred to as sloth fever?
The Lancet medical journal revealed that the virus resides in pale-throated sloths, as well as non-human primates and birds. However, the connection to sloths seems to have captured public attention, reports Gloucestershire Live.
Carolina Goncalves, superintendent pharmacist at Pharmica, clarified: “The term ‘sloth fever’ is a colloquial name that has emerged due to the virus being found in areas where sloths, which are known to carry a range of parasites and pathogens, are present,” She added, “However, the name is relatively misleading as it is spread by insect bites, not by direct contact with sloths.”
Why has this occurred?
Dr Enny Paixao, an associate professor at the London School of Hygiene and Tropical Medicine, has shed light on the factors behind the recent outbreak of oropouche virus: “Several factors may explain the recent outbreak, including enhanced surveillance, climate and environmental changes, and potential changes to the virus.”
She further elaborated on the impact of climate change on vector-borne diseases like oropouche, stating: “Similarly to other vector-borne diseases, such as dengue, climate change may also be impacting oropouche virus expansion. Changes to temperature and precipitation can affect transmission, for example, rising temperatures can enhance the rate of development of culicoides midges, one of the virus’ main transmission vectors in South America alongside mosquitos.”
Despite the virus not being new, Dr Paixao emphasised the urgency for more research due to the significant rise in cases. She said that, Although oropouche virus is not new, the factors driving the recent sharp increase 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 [and other affected countries] increases, the challenge posed by this neglected tropical disease will persist.”
Concerning the risk of ‘sloth fever’ in the UK, Dr Philip Veal, a travel health consultant at UK Health Security Agency (UKHSA), reassured the public: “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.”
The UKHSA also clarified that all European cases of the virus were contracted abroad, indicating that the risk within the UK remains low.
“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,” warned Paixao. In July, the PAHO issued a warning about the possible transmission of the oropouche virus from mother to child in Brazil.
“Some very limited studies have suggested that antibodies against the virus have been found in children born with microencephaly and that there may be a link between infection, miscarriage, and foetal deaths in Brazil, but further research is needed to investigate a potential causal link,” Paixao added.
What are the symptoms of ‘sloth fever’?
The London School of Hygiene and Tropical Medicine has outlined that common symptoms include a rash, headache, muscle or joint pain with weakness. Those affected will typically experience a fever illness three to eight days after infection.
Moreover, some individuals may also experience gastrointestinal symptoms and sensitivity to light. The research centre also noted that severe cases are rare but can lead to neurological symptoms similar to meningitis.
Can ‘sloth fever’ be treated?
“As of now, there are no specific antiviral treatments or vaccines available for oropouche virus,” Goncalves revealed. “Treatment primarily focuses on managing symptoms and providing supportive care.”
Patients are typically advised to rest, stay hydrated, and take over-the-counter pain relievers such as paracetamol to reduce fever and alleviate pain. “In more severe cases, hospitalisation may be necessary to provide supportive care, especially if complications arise, although severe cases are relatively rare,” added Goncalves.
What should I do if I am planning to travel to an affected area?
“When travelling to affected areas, you can avoid the infection by preventing insect bites. Use insect repellent, cover exposed skin and sleep under a treated bed net,” said Veal. “Plan ahead and visit the TravelHealthPro website to look up your destination and the latest health information and advice, particularly if you are pregnant.”