Since the outbreak of the Nipah virus in 2018, the deadly infection has once again entered the state of Kerala. Health Minister KK Shailaja on Tuesday, June 4, confirmed that a 23-year-old youth, who was hospitalised at Kochi, a few days back, was infected with the virus.

What is Nipah virus?

The name 'Nipah' comes from Sungai Nipah village in Malaysia from where it was first discovered among the pig farmers in 1999. It is a zoonotic virus, which is transmitted from animals to humans and can also be transmitted through contaminated food or directly between people.

The fatality rate of the Nipah virus infection is 40-75 per cent, where the human victim suffers a range of illnesses from asymptomatic (subclinical) infection to acute respiratory illness and fatal encephalitis.


The infected people will initially develop symptoms including fever, headaches, severe body pain, sore throat and vomiting. This can be followed by dizziness, drowsiness, altered consciousness, and neurological signs that indicate acute encephalitis.

Some people will also experience severe respiratory problems, including infections and acute respiratory distress. Encephalitis and seizures occur in severe cases, progressing to coma within 24 to 48 hours. The incubation period ranges from 4 to 14 days. 

Nipah Kerala
Students wear safety masks as a precautionary measure after the outbreak of 'Nipah' virus in Kozhikode, Kerala on May 22, 2018.IANS [Representational Image]

Key Facts

    • Nipah virus infection in humans causes a range of clinical presentations, from asymptomatic infection (subclinical) to acute respiratory infection and fatal encephalitis.
    • NiV can be transmitted to humans from animals (such as bats or pigs), or contaminated foods and can also be transmitted directly from human-to-human.
    • The Pteropodidae (colloquially known as the flying foxes or Old World fruit bats) family are the natural host of the NiV.
    • The case fatality rate is estimated at 40 per cent to 75 per cent. This rate can vary by outbreak depending on local capabilities for epidemiological surveillance and clinical management.
    • There is no treatment or vaccine available for either people or animals. The primary treatment for humans is supportive care.



There are no exact symptoms of NiV at the initial stage, and the diagnosis is often not suspected at the time of presentation. Due to this, there is no accurate diagnosis for the Nipah virus.

In addition, the quality, quantity, type, timing of clinical sample collection and the time needed to transfer samples to the laboratory can affect the accuracy of laboratory results. However, it can be diagnosed with clinical history during the acute and convalescent phase of the disease.

The main tests used in identifying NiV include real-time polymerase chain reaction (RT-PCR) from bodily fluids and antibody detection via enzyme-linked immunosorbent assay (ELISA). Other tests used include polymerase chain reaction (PCR) assay and virus isolation by cell culture.


As of now, there are no specific medication or vaccines for NiV although intensive supportive care is recommended to treat severe respiratory and neurologic complications.


  • Avoid eating fruits that are eaten or bitten by animals, especially bats. Freshly-collected fruits should be properly washed and peeled before consumption.
  • Avoid interaction with infected animals or humans without wearing protective measures.
  • If an outbreak is suspected, the animal premises should be quarantined immediately.

 (Inputs from WHO)