THIRUVANANTHAPURAM: The recurrence of Nipah in the Kozhikode-Malappuram area continues to perplex authorities and experts alike. Kozhikode reported outbreaks in 2018, 2021, and 2023, while Malappuram reported cases in 2018 and 2024. Ernakulam recorded a single case in 2019. Despite directives from the government to conduct extensive surveillance in Kozhikode to understand the persistence of the virus since September last year, there has not been much headway.
A study by the Indian Council of Medical Research (ICMR) detected Nipah virus antibodies in bats from Kozhikode and Wayanad. However, the reasons behind the virus’ localised impact and its transmission in humans remain unclear. Fruit bats, recognised as carriers, are widespread, and experts suggest multiple factors such as climate variations, environmental degradation, and the characteristics of index cases ( people who first contracted the virus from an animal) contribute to outbreaks in the Kozhikode-Malappuram region.
“When Nipah was first reported in Malaysia in 1998, it was pointed out that bats that were affected by El Nino came up to urban dwellings in large number. In Bangladesh and Bengal, the bat excreta led to the outbreak. We are yet to establish a clear link. But there is a commonality among the victims (index cases). All of them are males in the age of 12 to 25, who are active and adventurous,” said Dr Althaf A, a public health expert and professor at Government Medical College Hospital in Thiruvananthapuram. He pointed out that establishing the epidemiological link requires sustained efforts.
An animal pathologist who has done extensive study on bats in Kozhikode in 2018 said, on conditions of anonymity, that the virus-carrying bats may not be limited to Kozhikode and Malappuram.
“There are bats everywhere. There are also many places in Kerala which have conditions similar to that of Kozhikode which includes the presence of mangroves, urban forest, etc. We need to find if certain bat colonies harbour more viruses and the factors behind it. It is proven that bats unload more virus when they are stressed during the birthing, food scarcity, overcrowding, inclement weather etc,” he said.
Vigil tightened in Wayanad dist
District Medical Officer Dr P Dineesh has said that special vigilance should be exercised in Wayanad, following the confirmation of Nipah infection in Malappuram district. The 14-year-old who died of Nipah had gone on an excursion to Wayanad a week ago. Health centres in the district have been directed to strengthen surveillance activities further. The DMO said that people should be more cautious because the antibody was confirmed in bats from Noolpuzha and Mananthavady Pazhassi Park in the district last year.
