How Rift Valley fever is posing danger to pregnant women

Rift Valley fever (RVF) has been linked to the increasing number of miscarriages among women in Africa.

But there have been cases of miscarriages among women in the North-Eastern region, with studies still underway on if the virus could be blamed for preterm births.

RVF is a viral disease most commonly seen in domesticated animals in sub-Saharan Africa, such as cattle, buffalo, sheep, goats, and camels. People can get RVF through contact with blood, body fluids, or tissues of infected animals, or through bites from infected mosquitoes, according to CDC.

World Health Organisation (WHO), as of February 4, 2021, said there were 32 human cases of Rift Valley fever and 11 deaths, resulting in a case fatality ratio of 34.4 per cent.

Of those 32 positive cases, 14 were confirmed by polymerase chain reaction (PCR) testing at the National Virology Reference Laboratory.

Cynthia McMillen, a postdoctoral researcher in Hartman’s lab, said that women who contract the virus are more likely to have a miscarriage.

“Women with confirmed Rift Valley fever virus during pregnancy are 4.5 times more likely to have a miscarriage compared to uninfected women,” she said.

“Late-term miscarriage was also significantly associated with an acute Rift Valley fever infection.”

Isaac Ngere, an epidemiologist at Washington State University Global Health Kenya, said the virus perfectly attaches itself to the placenta leading to miscarriages.

He said that when the virus is transmitted through the infected fluids to the foetus, the foetus is affected immediately.

Speaking to the Star, Ngere said when a mother is infected with the RVF during pregnancy it could lead to maternal and foetal mortality, pregnancy loss, premature labour and congenital anomalies.

"Viruses interfere with the growth of cells, hence the brain cells could be affected, leading to poor cognition," Ngere said.

He said that a child may have learning difficulties if he or she gets infected with the virus while in the womb.

According to Ngere, some of the symptoms to look out for are fever, joint pain and headaches although occasionally symptoms are more severe to a point that they affect the liver, eyesight, brain and can also lead to uncoordinated body movement.

“It causes abortion because any virus that causes fever has a likelihood of detaching the placenta from the womb hence pregnancy loss. That is why we get concerned, especially when pregnant women get infected with the Rift Valley fever,” he said.

He said even domestic animals are affected when there is an RVF outbreak in the North-Eastern region.

"Pregnant livestock like sheep and goats may not be able to carry their pregnancies to term... Some people describe that as an ‘abortion storm’," Ngere added.

CDC notes that although RVF often causes severe illness in animals, most people with RVF have either no symptoms or a mild illness with fever, weakness, back pain, and dizziness.

"However, a small percentage (8-10%) of people with RVF develop much more severe symptoms, including eye disease, haemorrhage (excessive bleeding), and encephalitis (swelling of the brain)," CDC states.

How infection spreads

Women get infected with the virus through mosquito bites or when they are milking, slaughtering or consuming the infected animals.

Kenyans have been urged to sleep under treated mosquito nets, especially during the rainy season, to curb the spread of the viral disease.

According to experts, Isiolo is among the counties that have a high risk of Rift Valley fever because when it rains in the high lands, a lot of water flows all the way through Ewasi Nyiro and Lorian swamp leading to flooding.

The stagnant water offers spaces for mosquito breeding in those areas.

According to the Journal on Virology in 2007, a pregnant woman was hospitalized with fever, headache, dizziness, and muscle aches. Blood tests confirmed the presence of Rift Valley fever.

Labor commenced at 38 weeks and a male baby was delivered with an enlarged spleen and liver.

Umbilical cord blood contained rift valley fever antibodies. The mother and the child were later discharged on the third day.

The epidemiologist has urged the government to enhance resilience through long term solutions for mitigation of the effects of drought.

Access to water and social protection is vital for the people living in the North-Eastern to stop relying too much on dead or infected livestock for their survival.

Efforts are now underway to assess the extent of the outbreak in humans and to educate health workers and veterinarians about the disease.

"WHO is working with the Ministry of Health to promote community awareness of Rift Valley Fever, implement livestock movement control, and conduct inspections of herds both pre and post-mortem," the Johns Hopkins Center for Health Security.