Face masks are back in the quiet residential area of Melevaram near Farooq College in Kozhikode. From the random scooter rider to the health workers sitting outside the family health centre, everyone is wearing them.
The overarching sentiment is not fear or worry, but caution. The cause is not hard to ignore; A 43-year-old resident of the area has been diagnosed with the deadly Nipah infection.
However, one of their neighbours, Abdul Aziz, does not seem too worried. He says, “Health workers have told us that the infection does not spread as fast as COVID-19. They are visiting the place every day to keep an eye on the situation. But, yes, most of us are wearing face masks when we step out as a precaution.”
The infected person is on ventilator support at the Government Medical College Hospital (MCH), Kozhikode, since June 10. Venugopal, a relative who lives nearby, says his close family members are already in home quarantine.
contacts are under surveillance
He further added, “All his close contacts are now under observation. Lab tests are conducted if any of them show symptoms of infection. As of now, all of them have tested negative for the virus. Let’s hope he survives this ordeal.”
However, health workers attached to Ramanattukara Municipality, under which the area falls, are not taking any risks. The preliminary survey of more than 300 houses in the area has already been completed. Rajul Koyadin, medical officer attached to the local body, says a fever survey is underway to find out if any resident has symptoms related to the deadly zoonotic disease. The health department is also coordinating with animal husbandry and forest departments as part of the ‘One Health’ initiative to take preventive measures. A team from the Indian Council of Medical Research also visited the area.
mortality rate 75%
His vigilance has its own background. The mortality rate of Nipah, the virus that spreads infection, is up to 75%. It is usually spread to humans from infected bats and other animals and can also spread directly between people. Fruit bats of the Pteropus species are the natural hosts of this virus. Nipah is also one of the pathogens on the World Health Organization’s Research and Development Blueprint list of “pandemic threats requiring urgent action.”
Medical waste is being cleaned from the Nipah isolation ward at the Government Medical College Hospital, Kozhikode. | Photo courtesy: K. Ragesh
For the record, this is the fourth time Kozhikode is reporting a Nipah case. The first official case of Nipah in Kerala was reported from here in 2018. There have been 10 cases of infection in the state by 2025 and there have been 38 cases and 28 deaths so far. After 2018, Kozhikode reported one case in 2021 and an outbreak in 2023. Malappuram, Palakkad and Ernakulam are the other districts from where the cases have been reported.
TS Aneesh, nodal officer of the state government’s Kerala One Health Center for Nipah Research and Resilience, Kozhikode, highlights some patterns that have emerged from recurring cases of infection in the state. This virus has been found active in Kerala from April to September. The highest number of cases so far are in September.
“The fruiting season in the state is around April. The discovery of bats occurs during this period. Since fruit bats are the natural reservoir of the virus, transmission of infection through fruits may occur in that month,” he said. The breeding season of bats also occurs in April-May and again in September. “They become more aggressive and if they are disturbed virus shedding – the release of infectious particles into the environment – increases during these months.”
Another pattern is the emergence of Perinthalmanna in Malappuram and Kozhikode city as the two most important places in the Nipah calendar. They claim that the presence of corporate hospitals and tertiary care government hospitals in the region, where most of the patients are being admitted, is the reason for this scenario.
“Most of the cases are in six districts south of Kannur. The infection is moving southwards from Kozhikode to Malappuram and then to Palakkad and Thrissur, possibly due to the bats shifting from one place to another in their habitat,” says Dr Aneesh.
A nationwide survey conducted by the National Institute of Virology, Pune a few years ago had detected Nipah virus antibodies in fruit bats in nine states, including Kerala. A 2021 study revealed the presence of the virus in fruit bats in “several districts” across the state. According to another study by the Wildlife Biology Department of Kerala Forest Research Institute, since most of the bat habitats are near human habitation, there is always a risk of their spread. However, Nipah virus has never been isolated in any fruit samples collected and tested during the outbreak. Its transmission to humans through fruits bitten by bats remains a scientific possibility. However, every episode of infection brings doubts about its recurrence in Kerala, especially Kozhikode.
In many other states also
AS Anoop Kumar, a critical care specialist at a private hospital in Kozhikode, who played a key role in detecting Nipah cases in 2018, 2023, 2024 and this year, says the virus is present in many other states across the country. But such cases are often not diagnosed there because patients with high clinical suspicion are not being screened for Nipah in those places. “In Kerala, especially in Kozhikode, a group of doctors and health workers are familiar with its clinical features. Therefore, such patients are routinely screened because of our experience from the 2018 outbreak,” he says.
Dr. Anup Kumar also says that the present patient, who was initially admitted to a private hospital, did not have fever except in the initial period. Dr Anup Kumar says, “He had low sodium levels and had become unconscious. The radiologist interpreted the MRI scanning results as septic emboli or changes in the brain following a blood infection. We suspected Nipah because we are used to seeing such patients. Taking into account his medical history and clinical, radiological and laboratory features, the clinical screening criteria for Nipah included, his score was very high.”
Since most of the Nipah cases were first suspected in private hospitals and then referred to the public healthcare system, there are demands to strengthen the surveillance system in government hospitals also.
A Althaf, professor, community medicine, Government Medical College Hospital, Thiruvananthapuram, points out that recurring cases of Nipah in symptomatic patients also indicate the need for an “active surveillance” system. He says if Nipah-specific testing of Acute Encephalitis Syndrome (AES) and Acute Respiratory Distress Syndrome (ARDS) patients is done, more cases can be detected.
pre-emptive examinations
“Currently, the system is responding to infections only after they have detected them. If pre-emptive testing, also called active surveillance, is implemented, it could lead to more cases. In the first phase, it could be implemented in Kozhikode and Malappuram districts, which have reported the highest number of such cases so far.”
Health department data shows that there were 56 AES cases and 22 deaths in Kerala in 2023. The next year, the number of cases rose to 122 and there were 37 deaths. There were 172 cases and 20 deaths in 2025. There have been 62 cases and 12 deaths so far this year.
Dr. Althaf says that most of these patients were from the districts of North Kerala. Japanese encephalitis, West Nile fever, rabies infection and Nipah can cause AES. He believes, “At least some cases of AES in districts where it is being reported frequently are likely to be caused by Nipah infection.”
Dr. Anoop Kumar says that it can be difficult to detect Nipah patients in the initial stages because their clinical features are similar to some other diseases. However, he says that screening people suffering from AES and ARDS will go a long way in detecting more cases. Dr. Althaf and Dr. Anup Kumar suggest cost-effective tests like TrueNat instead of RT-PCR tests.
“Through this, more scientific information can be made available on the mode of transmission of the infection, the nature of its spread and preventive steps. If the infection is diagnosed early, effective treatment can be ensured and the patient can be saved,” says Dr. Althuff.
political controversy
Meanwhile, a political controversy has also erupted with the opposition alleging lapses in containment measures. Health Minister K.K. The sudden transfer of outgoing director of health services KJ Reena without officially informing Muraleedharan also sparked a controversy.
However, Muraleedharan says that all efforts are being made to save the patient’s life. “He was admitted to the hospital in a critical condition. His blood pressure and cholesterol levels are fluctuating. Remdesivir, an antiviral drug which is not currently available in India, was procured from Bahrain. Along with it, Ribavirin, a monoclonal antibody drug and another antiviral drug is being given,” he says.
Maximum vigilance and preventive measures are being taken to prevent further spread of the infection at healthcare facilities or among close contacts of the infected person.
The challenge posed by Nipah may be formidable, but the health system in Kerala is trying its best to contain the crisis with time-tested methods.
