An emerging virus dubbed ‘sloth fever’ has sparked concerns after 19 cases were confirmed in Europe, marking the first known instances of the virus on the continent. The European Centre for Disease Prevention and Control verified that 19 individuals within EU borders have contracted the virus.
The virus, known scientifically as the Oropouche virus (OROV), is an RNA arbovirus first identified in 1955 in the Trinidadian village of Oropouche. Transmission to humans typically occurs through the bite of infected biting midges, though mosquitoes can also spread the virus, according to experts from the London School of Hygiene and Tropical Medicine.
In July, the Pan American Health Organisation (PAHO) issued an epidemiological alert following a spike in reported cases across five countries—Brazil, Bolivia, Peru, Cuba, and Colombia.
The Lancet medical journal notes that the virus has a reservoir in pale-throated sloths, as well as in non-human primates and birds. The association with sloths has contributed to the virus being colloquially referred to as ‘sloth fever.’
Carolina Goncalves, superintendent pharmacist at Pharmica, explained, “The term ‘sloth fever’ has emerged because the virus was found in areas where sloths, known to carry various parasites and pathogens, are present.” However, she clarified that the name is misleading, emphasizing that the virus is spread through insect bites, not direct contact with sloths.
Dr. Enny Paixao, an associate professor at the London School of Hygiene and Tropical Medicine, discussed the worrying increase in oropouche virus cases. “Several factors may explain the recent outbreak, including enhanced surveillance, climate and environmental changes, and potential mutations in the virus,” she said. Dr. Paixao also raised concerns about the role of climate change in disease transmission, noting, “Like other vector-borne diseases such as dengue, climate change may be contributing to the spread of oropouche virus.”
She further explained that changes in temperature and precipitation can influence transmission dynamics, as rising temperatures can accelerate the development of culicoides midges, one of the primary transmission vectors in South America, along with mosquitoes.
The surge in oropouche virus infections underscores the urgent need for extensive research. Dr. Paixao emphasized that without significant advancements in vaccine development, insect control measures, and building natural immunity in affected populations, the problem is likely to persist.
