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The TLDR: A 12-year-old has died of the disease, and 11 others are now displaying symptoms. The return of Nipah to the state is raising worries about a virus that has a high fatality rate—but is far easier to contain than the coronavirus.
Tell me more about Nipah…
The virus: It is a zoonotic virus—which means it can be transmitted from animals to humans. Nipah’s natural host is a family of bats called Pteropodidae—which can spread severe disease to various farm animals including pigs. The name Nipah comes from Sungai Nipah, a village in the Malaysian peninsula where the virus was first identified during an outbreak of encephalitis (inflammation of the brain) among pig farmers in Malaysia in 1998/99. The disease it causes is called NiV.
How it spreads: Infected bats eat fruit, or urinate or drop feces in proximity to humans or animals—who then spread it to others. So either you have direct contact with infected animals or humans—or you consume contaminated food such as fruit or palm sap. The disease has a long incubation period—as long as 45 days—so people often pass it on before they realise they are sick. It can take anywhere between 4-14 days to show symptoms.
Compared to Covid: NiV is more lethal but also less infectious. The fatality rate (percentage of infections that result in death) is anywhere between 40-75%—based on past outbreaks. That’s compared to Covid’s 1.3% average. OTOH, NiV is far, far less infectious—and requires close contact with nasal or respiratory droplets, urine, or blood. That’s unlike the coronavirus which can spread through airborne droplets. Nipah’s reproductive number—the number of people that one person can infect—is as low as 0.33. This means 10 people can at best infect three other people. For the original Wuhan virus, this number is 2-3, and it’s even higher for the Delta variant: between 5-6.
Symptoms: NiV is a very nasty disease. It typically starts with flu-like symptoms: fever, headaches, vomiting and sore throat. But it can then progress to dizziness, drowsiness, altered consciousness and signs of encephalitis—the inflammation of the brain. Patients can develop severe respiratory problems. And in the worst cases, encephalitis and seizures will progress to coma within 24 to 48 hours.
Treatment: There are no specific drugs to treat NiV or vaccines to prevent infection. Once a person falls ill, doctors typically treat the symptoms, and offer supportive care—hoping the patient’s body will be able to fight off the virus. Since NiV is a poor person’s disease, epidemiologists say there has been little incentive to find a cure:
“There’s a market failure for protecting people from this. It’s not like treating baldness or breast cancer, where wealthy people will pay for your product. There’s no big customer here, no incentive, until it escalates.”
Point to note: There is a version of ‘long haul’ NiV where survivors show persistent neurological effects, including personality changes. Also this: “The disease is also so deadly that many governments classify it as a bioterrorism threat and limit the laboratories that are allowed to culture and study it.” And this:
“Each year, the World Health Organization (WHO) reviews the large list of pathogens that could cause a public health emergency to decide how to prioritise their research and development funds. They focus on those that pose the greatest risk to human health, those that have epidemic potential, and those for which there are no vaccines. Nipah virus is in their top 10.”
And Nipah is only in Kerala?
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