The moment Victory Ovuoreoyen heard he had Lassa virus, he thought it was the end. The tradesman could barely walk and feared for his life when admitted to the Federal Medical Centre in the city of Owo in southwestern Nigeria. He ran a fever, was vomiting and had severe diarrhea.
But after four days in an isolation ward, the emaciated patient can now sit upright on his hospital cot, one of the few patients in the infirmary strong enough to speak. “Before I fell ill, I could not count my bones like this. I lost so much weight,” he says, pointing at his clavicles clearly showing under his loose mustard-colored shirt.
Doctors have assured the 48-year-old man that he will recover from the illness, an acute hemorrhagic disease similar to Ebola. He is lucky. Although 80 percent of those infected do not get very ill from the virus and most cases go undiagnosed, the death rate among those who end up in hospital is 15 percent, according to the World Health Organization. With an incubation period of between two and 21 days, severe symptoms can start showing a week into the illness. By then it could be too late.
Lassa fever lowers the platelet count in the blood and its ability to clot, causing internal bleeding. Fatal organ failure can follow within days.
Early symptoms include head and muscle aches, sore throat, nausea and fever. Initially, they are indistinguishable from the symptoms of malaria, a common disease in the region. The laboratory of this hospital in Owo is the only one in the state that performs the Lassa diagnostic blood tests and the results are only available after two days. This combination of factors often leads to Lassa being discovered at a late stage, which makes it harder to treat.
Owo, an agricultural market Centre 300 kilometers (186 miles) from the Nigerian capital Abuja, is the epicenter of the Lassa outbreak that began early this year, causing more than 160 deaths. At its height in March, the 38 beds in the isolation ward did not suffice and 10 more cots were added for suspected cases. In this part of Nigeria, people fear the Lassa virus far more than the coronavirus. With good reason: Ondo, the state where Owo is located, has since 2020 recorded 171 deaths caused by Lassa, versus 85 from COVID-19, according to the Infection Control and Research Centre at the hospital.
‘It is so contagious’
Head nurse Josephine Funmilola Alabi checks the intravenous drip that administers Ovuoreoyen’s antiviral medication and treats dehydration, an issue severely ill Lassa fever patients must battle. Alabi is dressed in a white hazmat suit, surgical cap, face mask and face shield. Only dressed like this may she enter the “red zone”, as the isolation ward for highly contagious patients is called. She also wears disinfected rubber boots and two pairs of surgical gloves. Not a millimeter of her skin is left uncovered. “We take this virus very seriously. It is so contagious that we are only allowed to enter the ward with full PPE,” Alabi says, referring to the personal protective equipment that medical personnel caring for patients with highly infectious diseases wear. Four of the Lassa deaths in Nigeria this year were of medical workers.
Despite its widespread presence in West Africa, the disease remains little known in much of the world. The virus was discovered in 1969 in the northern Nigerian town of Lassa, about 1,000km (621 miles) from Owo. Since then, it has become endemic in at least five countries in West Africa. Nigeria, Africa’s most populous nation, registers the highest number of cases, up to 1,000 a year. This year, in January alone, Nigeria recorded 211 confirmed cases, of which 40 patients died.
Lassa fever infects an estimated 100,000 to 300,000 Africans each year, of which thousands die, according to the Africa Centers for Disease Control and Prevention.
Infected people can infect others through bodily fluids. The fever often causes miscarriages and can be passed from mothers to babies. It can remain in breast milk for up to six months. Like other viruses causing hemorrhagic fevers that have no cure and are easy to reproduce, scientists have warned that the Lassa virus could be used as a biological weapon.
‘Diseases don’t have boundaries’
The fever tends to strike in impoverished rural areas and food contaminated with rat droppings or urine is often the source of infection. Roasted game, known locally as bushmeat, can also be tainted if the slaughtered animal has been in contact with the rodents. The rats often enter people’s houses in search of something to eat when the rains stop. That is why Lassa fever typically peaks in Nigeria’s dry season, from November to April, although cases persist all year round.
It is not spreading over the world as rapidly as COVID-19 did, says clinical microbiologist Adebola Olayinka. But she warns that this may change. She is an expert in infectious hazardous diseases and coordinates Lassa fever research for the Nigeria Centre for Disease Control. “Look at the story of Ebola,” she says. “This existed in the Democratic Republic of Congo for decades, but in 2014 very quickly reached West Africa and then England and the US.”
No proven drugs or vaccines protect against Lassa fever, Olayinka says. Currently, the only pharmaceutical used against Lassa fever is ribavirin, an antiviral drug commonly used to treat Hepatitis C. But its effectiveness against the Lassa virus has not been thoroughly researched, and pre-clinical studies and expensive clinical trials are needed to prove the efficacy of the drug. She believes the lack of research into Lassa is because the virus rarely appears in the West.
“Look at the speed with which the COVID vaccine has been developed,” she says. “But if an infectious disease doesn’t affect the wealthy, it won’t get the same amount of attention.” A year after the outbreak of the pandemic in 2020 the Access to Medicine Index compiled an inventory of the research and development efforts of the 20 largest pharmaceutical companies. It counted 63 projects concerning coronaviruses, five covering Ebola and zero for hemorrhagic viruses spread by rodents like Lassa, mostly found in Africa and Latin America.
Yet the West is not invulnerable to Lassa. Earlier this year, a couple in England was diagnosed with the disease. The husband contracted it during a visit to Mali and then infected his pregnant wife. Their premature baby died of the virus in a Bedfordshire hospital. “The West needs to realize that a disease anywhere could be a disease everywhere,” warns Olayinka. “Diseases don’t have boundaries.”