Experts have issued a new warning about the dangers of terrifying ‘sloth fever’ after the virus passed from a pregnant woman to her unborn baby, resulting in a stillbirth.
Oropouche virus, nicknamed ‘sloth fever’, caused alarm earlier this year after it spread outside of its usual South American range to Spain, Italy, Germany and the US.
The virus — named after the animal it was initially spotted in — has no vaccine or specific treatment.
It is known to cause a headache, muscle aches, stiff joints, nausea, chills, sensitivity to light and vomiting.
However, it can quickly cross the blood-brain barrier and enter the central nervous system, where it can cause meningitis and, in extreme cases, kill.
It is mostly spread by biting insects but there is limited evidence it can pass through sex.
Until now, experts thought only two cases of the virus passing between mother and child had been confirmed.
Now, in further alarming evidence of the virus’s potential to cause catastrophic consequences, medics have reported another case resulting in stillbirth.
Medics documented the case in the northeastern Brazilian state of Ceará, where a 40-year-old woman who at 30 weeks pregnant was infected with the oropouche virus.
The unnamed woman developed fever, chills, muscle aches, and a severe headache in July this year.
Just three days later she started to experience light vaginal bleeding as well as dark discharge from the area.
Her symptoms would continue for the next nine days and while signs initially suggested the foetus was fine subsequent scans confirmed that her baby had died during this period.
Molecular testing of samples taken from her confirmed she had been infected with the oropouche virus.
Tests of the stillborn child, a boy, found no developmental disorders but analysis revealed the presence of the virus in his brain, spinal fluid, lungs, liver, umbilical cord as well as the placenta.
Writing in the New England Journal of Medicine, the authors said: ‘These findings emphasise the risks of oropouche virus infection in pregnancy and the need to consider this infection in pregnant women with fever or other suggestive symptoms who live in or visit regions in which the virus is endemic or emerging.’
It comes just months after over a dozen cases of oropouche virus were detected across Europe.
While nicknamed ‘sloth fever’, oropouche isn’t spread directly by the animals themselves but instead by small biting insects like midges that can carry the disease from the sloths to other animals, including people.
Oropouche symptoms typically start four to eight days after being bitten.
Although potentially deadly, the fatal outcomes are extremely rare and recovery from the disease is common. In most cases symptoms subside within four days of onset.
Oropouche’s exact impact on pregnancy is still being studied by experts. However, cases of miscarriage and increased risk of a birth defect called microcephaly —which results in babies having a very small head — have been documented before.
The virus belongs to the same family of pathogens as Zika, which is known to increase the risk of miscarriage and birth defects.
Cases of oropouche remain low in Europe, with all cases believed to be linked to people travelling to affected areas and falling ill upon their return.
However, between January and mid-July this year more than 8,000 cases have been recorded in Brazil, Bolivia, Peru, Columbia and Cuba.
Due to a high number of cases European health officials warned citizens travelling to or residing in epidemic areas about a moderate risk of infection.
They advised those in affected areas to wear insect repellent, long-sleeved shirts and long trousers to reduce the risk of bites.
Experts say the oropouche is unlikely to ‘take hold’ in nations with cooler climates like Britain, but it could become a problem for those travelling abroad.
Analysis of the current oropouche strain suggests it has grown to become more efficient at infecting people and this could be behind the rise in cases and in areas it hasn’t been seen in before.
Climate change is thought to contribute to the rise, as habitat destruction has increased the interaction between humans and the animals that potentially carry the disease.
Oropouche was first spotted in an area of the same name in Trinidad and Tobago, back in 1955.
Five years later, during the construction of a highway, a sloth was tested and found to carrying the oropouche giving rise to its nickname.
However, multiple animals, not just sloths, are thought to be potential carriers of the virus.
Most previous outbreaks of the virus, of which there have been over 30 have been centred in the Amazon basin.
