There’s one part of the human body that the Rift Valley Fever virus likes more than the liver — the placenta.
That alarming discovery was recently made by a team of scientists that published its research in the journal Science Advances.
The Rift Valley Fever is not new. The mosquito-borne virus has long affected people throughout sub-Saharan Africa, where thousands of people have died from the illness that causes causes flu-like symptoms and extreme liver problems. In 2000, the virus spread to Saudi Arabia and Yemen, where it infected more than 100,000 people and killed 700, according to the New York Times.
But the virus’ alarming ability to cause stillbirths and miscarriages in livestock inspired scientists to take a closer look at its potential.
And now they say Rift Valley Fever could be more dangerous to pregnant women than Zika, the mosquito-borne virus that created a global panic in 2015, and caused thousands of birth defects.
Human fetuses are shielded from most pathogens by the placenta, but a select few can get beyond barriers and cause harm.
The Zika virus is able to take an indirect route into the placenta. The Rift Valley Fever, on the other, takes the “expressway” into the area, eschewing the liver and instead clustering around the fetus for reasons that are as yet unknown, according to the Times.
So far, two cases of a fetus infected by Rift Valley Fever have been documented, with one infant dying soon after being born. The researchers believe that it’s likely that other fetal infections have eluded detection because of a lack of knowledge about the disease.
The researchers found out about the risk it poses to pregnant women by studying pregnant rats. Of the infected rat mothers, 65% lost their pups, compared to 25% in the control group. All of the pups born to infected mothers, meanwhile, carried the virus.
The mosquito that carries Rift Valley Fever is found throughout the Americas and Europe as well, and the likelihood that climate change will expand the range and duration of seasonal mosquito populations means that more people are at risk of being infected in the years ahead.
In fact, the Coalition for Epidemic Preparedness Innovations (CEPI) identified Rift Valley Fever as one of 11 viruses in urgent need of a vaccination, lest they result in a catastrophic pandemic in the decades ahead.
The public health expert Dr. Jonathan Quack argues in his latest book The End of Epidemics that the next pandemic could kill 300 million people due to global travel patterns, vulnerable health systems, and climate change.
The World Health Organization currently considers the virus a potential public health emergency, and urges vulnerable countries to invest in measures that limit exposure to mosquitos and to separate livestock that are more likely to get infected from human populations.
There are currently no vaccinations for Rift Valley Fever, although the new research into the virus has sparked calls for funding, and CEPI has gathered $48 million to finance eight projects.
“Zika caught everybody by surprise,” Amy Hartman, an infectious disease specialist who led the research, told the Times. “If doctors had known about Zika’s birth effects, they could have done a lot more to protect pregnant women and babies. With Rift Valley fever, we’re trying to get ahead of the curve.”