Nipah Virus Explained: Why Even a Single Case Triggers High Alert

Five confirmed cases of the deadly Nipah virus in West Bengal have rung alarm bells across hospitals, governments, and public health agencies. Unlike many infections that require clusters before action begins, Nipah is treated as a medical emergency from the very first patient. The reason is simple: it is one of the deadliest viruses known to infect humans, with a history of sudden outbreaks, rapid deterioration, high fatality rates, and no cure. Nipah virus is a zoonotic disease, which means it spreads from animals to humans. Fruit bats of the Pteropus species are the natural carriers. The virus passes to humans through contaminated fruits, raw date palm sap, or close contact with infected animals like pigs. More concerning, however, is its ability

to spread from human to human, especially in healthcare and household settings.

Nipah spread in West Bengal

At least five people – mostly nurses and doctors have been confirmed infected, and more than 100 people have been quarantined due to the infection. Those quarantined have been kept at home while the infected patients are being treated in hospitals in and around Kolkata, according to media reports, with one patient in a critical condition. The outbreak is mostly centered around the town of Barasat near Kolkata, and the two initially infected patients still remain in the intensive care unit of the local hospital. Subsequent testing identified three further infections among healthcare workers at the same facility — a doctor, another nurse, and a health staff member.

Why is the Nipah virus extremely dangerous?

Nipah is particularly dangerous due to its high case fatality rate, which ranges from 40 to 75 per cent depending on the outbreak and quality of medical care. There is no specific cure and no approved vaccine yet. Treatment is largely supportive, which helps manage fever, breathing issues, and brain swelling, making early detection and containment the primary defence.

What are the symptoms of the Nipah virus to look out for?

The symptoms often begin deceptively mildly.

• Fever
• Headache
• Muscle pain
• Sore throat

All of these signs can resemble common viral illnesses. Within days, some patients develop acute encephalitis, an inflammation of the brain that leads to confusion, seizures, coma, and, in severe cases, death. Respiratory distress may also occur, increasing the risk of transmission to caregivers and medical staff. This unpredictable progression is one of the reasons why a single confirmed case triggers immediate containment measures. Once Nipah is suspected, health systems move fast with the isolation of the patient, identification and monitoring of contacts, travel restrictions, and strict infection-control protocols in hospitals. Even those with mild symptoms or indirect exposure are often quarantined as a precaution.Also read: What is the Nipah Virus? Symptoms to Watch as India Races to Contain Deadly Outbreak

Nipah identified as priority pathogen

The World Health Organization has classified Nipah as a priority pathogen, which means a virus with epidemic potential that requires urgent research and preparedness. Experts warn that environmental changes like deforestation, urban expansion, and climate stress are increasing human contact with wildlife, raising the risk of spillover spread like Nipah. Another reason for high alert is the speculation, which experts feel is mostly misunderstood, that it has pandemic potential. Nipah does not spread as easily as COVID-19, but its combination of high lethality and human-to-human transmission makes it a serious threat if mutations improve its spread. Public health officials stress that panic is unnecessary, but awareness is crucial.