Kerala’s health machinery goes all out to keep Nipah in check
Face masks have returned to the quiet residential neighbourhood of Melevaram near Farook College in Kozhikode. From the random scooter rider to the health workers
Face masks have returned to the quiet residential neighbourhood of Melevaram near Farook College in Kozhikode. From the random scooter rider to the health workers huddled outside a family health centre, everyone is wearing them. The pervasive sense is not fear or anxiety, but caution. The reason is not hard to miss; a 43-year-old resident of the locality has been diagnosed with the deadly Nipah infection. Abdul Azeez, one of his neighbours, doesn’t seem to be overly worried though. “Health workers have told us that the infection doesn’t rapidly spread like COVID-19. They are visiting the place to monitor the situation every day. But, yes, most of us are wearing face masks while going out as a precautionary measure,” he says. The infected person has been on ventilator support at the Government Medical College Hospital (MCH), Kozhikode, since June 10. His close family members are already under home quarantine, says Venugopal, a relative who stays nearby. Contacts under observation “All his close contacts are now under observation. Lab tests are held if any of them exhibit any symptoms of the infection. So far, all of them have tested negative for the virus. Let’s hope he will survive the ordeal,” he adds. Health workers attached to the Ramanattukara municipality, in which the locality falls, are not taking any risks, however. A preliminary survey of the 300-odd houses in the area has already been completed. Rajul Koyadeen, medical officer attached to the local body, says a fever survey is going on to find out if any of the residents have had symptoms related to the deadly zoonotic disease. The Health department is also coordinating with the departments of Animal Husbandry and Forest as part of the ‘One Health’ initiative, while taking up containment steps. A team from the Indian Council of Medical Research too visited the area. Mortality rate of 75% Their alertness has its own background. Nipah, the virus causing the infection, has a mortality rate of up to 75%. It usually transmits from infected bats and other animals to humans and can also be transmitted directly between people. Fruit bats of the Pteropus species are the natural hosts of the virus. Nipah is also one of the pathogens in the World Health Organisation’s Research and Development Blueprint list of “epidemic threats needing urgent action”. For the record, this is the fourth time Kozhikode is reporting a Nipah episode.
The first official Nipah case in Kerala was from here, in 2018. There have been 10 episodes of the infection in the State till 2025, and 38 cases and 28 deaths so far. After 2018, there was a single case in 2021 and an outbreak in 2023 in Kozhikode. Malappuram, Palakkad, and Ernakulam are the other districts from where cases have been reported. T.S. Anish, nodal officer of the State government’s Kerala One Health Centre for Nipah Research and Resilience, Kozhikode, highlights some patterns that have emerged from the recurring instances of the infection in the State. The virus is found to have been active in Kerala from April to September. The highest number of cases so far has been in September. “The fruiting season in the State is around April. Bat foraging happens during the period. Since fruit bats are the natural reservoirs of the virus, the transmission of the infection through fruits can happen in that month,” he observes. The breeding season of the bats is also in the April-May period and then in September. “They become more aggressive and virus shedding — the release of infectious particles into the environment — increases in these months if they are disturbed,” he explains. Another pattern is the emergence of Perinthalmanna in Malappuram and Kozhikode city as the two most important places in the Nipah calendar. The presence of corporate hospitals and tertiary care government hospitals in this region, where most of the patients are getting admitted, is the reason for the scenario, he claims. “Most of the cases have been in the six districts that are south of Kannur. The infection is also going southwards from Kozhikode to Malappuram, and then to Palakkad and to Thrissur, possibly because of the shifting of the bat roosts from one place to another,” notes Dr. Anish. A nationwide survey conducted by the Institute of Virology, Pune, a couple of years ago had detected Nipah virus antibodies in fruit bats in nine States, including Kerala. A 2021 study had revealed the presence of the virus in fruit bats in “many districts” across the State. Since most of the bat-roosting sites are near human habitats, as per another study by the Kerala Forest Research Institute’s Department of Wildlife Biology, there is an ever-present threat of a spillover. However, the Nipah virus has never been isolated in any fruit samples collected and tested during the outbreaks.
The BriefWire