An insect-transmitted virus that can infect sloths, primates, and birds is spreading at an “unprecedented” rate, according to global health officials. Oropouche fever, a potentially fatal zoonotic disease, is now emerging in parts of the world where it has never been detected before, including Europe. The World Health Organization (WHO) has reported that the virus, transmitted by tiny flies called midges and mosquitoes, is spreading beyond its traditional stronghold in Central and South America.
Oropouche fever, which is part of the same family of diseases as Zika and dengue fever, has traditionally circulated in Central and South America. However, recent research published on August 8 in The Lancet indicates that the virus has also been detected in new locations, including Cuba, Italy, and Spain.
The research paper noted that “Arboviral infections have hit South America heavily in the past decade…. In addition, the region is now facing the re-emergence of another little-known arbovirus, Oropouche virus, on an unprecedented scale.” As of August 1, 2024, there have been 8,078 confirmed cases in Bolivia, Brazil, Colombia, and Peru, compared to just 832 cases reported in 2023. The first deaths linked to Oropouche fever were reported in late July, involving two young women in Brazil with no underlying medical conditions.
In response to the virus’s spread, both the Pan American Health Organization (PAHO) and the European Centre for Disease Prevention and Control (ECDC) have issued warnings. In June and July, Europe reported its first 19 cases of Oropouche virus disease, with Spain (12 cases), Italy (five cases), and Germany (two cases) being affected. The majority of these cases were linked to travel to Cuba, with one case connected to Brazil.
Dr. Isaac Bogoch, a Toronto-based infectious diseases specialist, expressed concern over the virus’s potential spread to Canada, especially given the rise in cases in popular travel destinations like Cuba. “There’s a giant knowledge gap,” Bogoch said, highlighting that many healthcare professionals and the general public may be unaware of the virus, which could lead to underreporting.
Oropouche fever is a zoonotic disease first identified among forest workers in Trinidad in 1955, and later in a sloth in Brazil in 1960. Since then, more than 500,000 cases have been reported in the Americas, though the true extent of the virus’s spread may be underestimated. The virus is primarily transmitted to humans through the bite of an infected midge or mosquito, with no direct human-to-human transmission documented so far.
Symptoms of Oropouche fever can resemble those of dengue fever and Zika virus, including fever, chills, nausea, vomiting, headache, joint pain, muscle pain, sensitivity to light, and pain behind the eyes. In rare cases, the virus can lead to severe complications such as aseptic meningitis, which involves inflammation of the membranes surrounding the brain.
The spread of Oropouche fever has been linked to climate change, urbanization, and deforestation. A study from 2017 examined an outbreak in Peru and found a significant connection to deforestation, which may displace the virus’s animal hosts and increase the likelihood of midges feeding on humans. Extreme weather conditions such as heavy rainfall and flooding, which create ideal breeding conditions for midges, have also been identified as contributing factors.
Currently, there is no vaccine or specific treatment for Oropouche fever. Prevention is the best defense, with the Centers for Disease Control and Prevention (CDC) recommending the use of insect repellent, window and door screens, and fans to keep midges and mosquitoes at bay. Since midges are smaller than mosquitoes, traditional mosquito nets may not be effective.
“Good insect repellent works extraordinarily well,” Bogoch advised, recommending repellents containing 30% DEET or 20% picaridin for the best protection.
The Canadian government has also issued travel precautions, advising those traveling to regions with Oropouche fever outbreaks to take extra care, particularly pregnant women, due to the potential risk of transmission from mother to fetus.
As the virus continues to spread, health officials urge travelers and healthcare providers to remain vigilant and report any symptoms that could be related to Oropouche fever. The situation highlights the growing threat of infectious diseases in a rapidly changing global climate.