Nipah: why is this virus, for which there is no vaccine, such a concern for the WHO?

An unwelcome visitor from the forests

It’s a scenario that, unfortunately, is becoming familiar to us. We encroach on forests, expand our cities, and suddenly the barrier between humans and wild animals disappears. This is exactly what happened with the Nipah virus. You may not have heard much about it, but it is on the World Health Organization’s (WHO) radar as one of the most serious threats of the moment. Why? Because it keeps coming back in South Asia and, to date, we have no vaccine to stop it. It all started in 1999. At the time, an epidemic struck Malaysia and Singapore, initially affecting pig farmers. Tracing the virus back, scientists found its natural reservoir: fruit bats, the large flying foxes that inhabit the tropics. Since then, the virus has traveled. Cases have been reported in the Philippines, Bangladesh, and, more recently, India.

How does the virus spread to humans?

In practical terms, how do you catch this virus? It’s not always direct. Often, it’s through contaminated fruit. An infected bat nibbles on a mango or a date, leaving saliva or urine on it, and if a human consumes this fruit, contamination occurs. In India, researchers have identified several species of fruit bats that carry the virus. But the danger doesn’t stop there. The virus can also be transmitted from person to person via bodily fluids. This is where it gets complicated for healthcare workers. The Independent newspaper recently reported that doctors and nurses were infected in the state of Kerala in 2023. This shows how fragile hospital protection protocols can be when faced with such an adversary.

A chilling mortality rate

What makes Nipah particularly dangerous is its initial discretion followed by extreme violence. It advances masked: incubation can last up to three weeks. At first, it looks like a simple flu with fever, body aches, and headache. Classic, right?

Except that things can quickly spiral into encephalitis, or inflammation of the brain. Confusion, convulsions, even coma… The clinical picture is grim. The WHO figures are clear: the fatality rate ranges from 40% to 75% depending on the epidemic. And for those who survive? They are not always out of the woods, with risks of persistent neurological sequelae or even late relapses.

India on high alert

Faced with this threat, the Indian authorities are taking no chances. When the alert was issued in 2023, the response was massive. The Ministry of Health sealed off nine villages and banned public gatherings. Imagine the scale of the task: teams visited more than 53,000 homes to screen for possible cases, as reported by the WHO.

In the district of Kozhikode, which has already suffered three waves in less than five years, the system is well-oiled. Dedicated ambulances, reinforced isolation units, and even psychological support for the population. The National Institute of Virology has confirmed that the current strain is similar to the one in Bangladesh, proving that the virus is indeed circulating in the region.

Nipah may not spread as quickly as Covid-19, but its high lethality makes it a sword of Damocles. Until there is a treatment or vaccine, our only defense remains surveillance and, above all, better management of our coexistence with wildlife.

According to the source: science-et-vie.com Created by humans, assisted by AI.