Scientists fear the virus, which is spread primarily through culicoides paraensis and Aedes mosquitos from sloths, has the potential to be the next one to cause a big outbreak in South America.
The continent has fiercely battled against epidemics of Zika and Chikungunya in the past decade, and now faces one of the worst Dengue epidemics ever.
Zika infections during pregnancy can cause infants to be born with microcephaly, an abnormal smallness of the head, and other congenital malformations as well as preterm birth and miscarriage.
“It’s part of a pattern in recent years whereby the Americas are seeing more widespread cases of vector-borne disease: this year a particularly bad one for Dengue with concerns also for Chikungunya virus and now cases of Oropuche,” Danny Altmann, a Professor of Immunology at Imperial College London, told the Telegraph.
“People in Brazil are worried about yet another arbovirus getting a foothold as they’ve paid such a high price – health and economic – for introduction over recent years of Zika and Chikungunya.”
‘There’s a lot we don’t know’
Oropouche is an arboviral disease – an infection caused by a group of viruses spread to people by the bite of infected arthropods such as mosquitoes and ticks – like Chikungunya, Zika and Dengue.
Most cases of Oropouche are mild, with symptoms similar to Dengue, including a headache, body pains, nausea, and rash, but the virus can also attack the brain.
Suspected fatalities are currently under investigation.
Experts fear that even a small epidemic could overwhelm South America’s already stretched healthcare system.
What worries scientists the most is that much of the science behind the virus and its spread is unknown.
“With Oropouche itself, there’s a lot we don’t know regarding its transmission – what insects it can be transmitted by, what animals might act as reservoirs for that disease. There’s a gap in knowledge about where we expect this virus to turn up. Can it be transmitted easily to other regions, like North America?” Dr Christopher Sanders, Institute Fellow at the Pirbright Institute, said.
The strain behind the recent outbreak was first spotted in the tiny village of Oropouche, in Trinidad and Tobago, back in 1955.
Five years later a sloth was tested as carrying Oropouche during the construction of the Belém-Brasília highway.
Within a year people in the area were struck down by Oropouche fever, and around 30 outbreaks have been reported since, all of these centred in the Amazon basin.
In the jungle, the virus circulates between primates, sloths, and birds, but it remains unclear which insect spreads it there.
Tiny culicoides paraensis and Aedes mosquitos distribute the disease among humans in urban settings.
The current outbreak was first noted in Roraima, a state in northern Brazil, and it has now stretched across the country’s heavily populated East Coast, including the states of Rio de Janeiro, Santa Catarina, Bahia, and Minas Gerais.
Only a handful of these patients had travelled to the Amazon basin, meaning Oropouche is now being transmitted locally.
