Nipah virus in Kerala: What we know so far

India’s southern state of Kerala has reported a sixth case of the Nipah virus. Kerala state authorities said the case was a 39-year-old man in Kozhikode district, who had sought treatment at a private hospital where other Nipah virus-affected patients were treated for ailments earlier.

Kerala’s Health Minister Veena George’s office said that the 39-year-old man has been confirmed with the Nipah virus after his samples turned positive. He remains under observation in a hospital.

The zoonotic virus, transmitted between species from animals to humans, has already killed two people in Kerala this year. This is the fourth outbreak in the state since 2018.

Kerala government authorities have announced the closure of select schools and offices, in a bid to contain the spread of the deadly Nipah virus.

What we known about the Nipah virus

Origin of the virus

The Nipah virus was initially identified in 1998 during an outbreak among pig farmers in Malaysia and Singapore.

It has the capability to directly infect humans through contact with the bodily fluids of infected bats and pigs. There have been documented cases of human-to-human transmission.

Scientists believe that Nipah has existed among flying foxes (a type of bat) for an extended period and express concerns about the potential emergence of a mutated, highly transmissible strain from bats.

Symptoms and treatment

There are currently no vaccines available to prevent or cure the infection, which has a mortality rate of approximately 70 per cent.

Treatment primarily involves providing supportive care. Infected individuals typically experience initial symptoms such as fever, respiratory distress, headaches, and vomiting, according to the World Health Organization (WHO).

In severe cases, encephalitis and seizures may occur, sometimes leading to a coma.

Previous outbreaks

The virus has a history of outbreaks. The 1998 outbreak in Malaysia and Singapore resulted in the deaths of over 100 people and infections in nearly 300 individuals.

Since then, it has spread across multiple countries, with mortality rates ranging from 72 per cent to 86 per cent among those infected.

WHO data indicates that more than 600 cases of Nipah virus infections in humans were reported from 1998 to 2015.

In India, a 2001 outbreak and subsequent outbreaks in Bangladesh claimed the lives of 62 out of 91 infected individuals.

Recent outbreaks in Kerala

In 2018, an outbreak in Kerala claimed the lives of 21 people, with additional outbreaks occurring in 2019 and 2021.

An earlier investigation in May identified parts of Kerala as one of the most vulnerable regions globally to bat virus outbreaks, according to a Reuters report.

Presently, experts are actively collecting samples from bats and fruit trees in Kerala as part of efforts to understand and combat the Nipah virus.

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