Kerala sounds alert after Nipah virus cases detected in Palakkad and Malappuram districts

Health Minister Veena George said the alert has been sounded in Kozhikode, Malappuram and Palakkads, where 345 persons are in the contact list of the two cases, which were confirmed after samples tested in NIV-Pune.

In Palakkad, a 38-year-old woman, from Nattukal village, is undergoing treatment at a private hospital at Perinthalmanna in Palakkad. The source of infection is yet to be ascertained, but local people reported the presence of fruit bats, which are known as reservoir of the virus in the region. The 18-year-old woman hailed from Makkaraparamba village in Malappuram. She died in a private hospital in Kozhikode on July 1.

Since doctors were clueless about the cause of death, her postmortem was held and samples were tested for Nipah virus. Both cases were confirmed on Friday from NIV-Pune.

The minister said of the 345 persons in the contact list of the two cases, 43 are health workers in Kozhikode, where the diseased victim was treated. Contact tracing will be strengthened, route maps of the two cases will be published to enable self reporting and containment zones will be notified as part of preventive measures.

She said the victims had developed symptoms on June 25 and 26. Directions were given to verify whether the areas of the victims had reported cases of encephalitis or phenomena. As many as 26 committees each have been formed in the district as part of the containment steps.

In May this year, Kerala had reported a Nipah positive case in Malappuram. The victim, a woman, survived the infection.
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Kerala has had five Nipah outbreaks since 2018. Till now, only seven positive patients, including the woman in May, have survived. In 2018, 17 out of 18 infected persons and one in 2021 had died. In 2023, two Nipah deaths were reported. Last year, Malappuram had reported two deaths — one in July and the second in September – taking the total in Kerala since 2018 to 22.

Fruit bats are known as the reservoir of the deadly virus and all the outbreaks in Kerala had been reported during May to September, mainly the rainy season in the state. During the rainy season viral fever and influenza are common, which makes early diagnosis of Nipah difficult.

A study on the 2018 outbreak had found that the index case was infected from bats, while others from hospital. The virus reported in Kerala belonged to a Bangladeshi strain, which is known for a mortality rate — even up to 90 per cent.

A field survey conducted by the National Institute of Virology (NIV) and the National Institute of High Security Animal Diseases (NIHSAD) after the Nipah death in July last year indicated fruit bats as the source of infection. The presence of antibodies of the virus was detected in fruit bats collected from Pandikkad village, where the July victim lived.

The minor boy had consumed hog plum fruit from his neighbourhood, where fruit bats were known to be present.

An analysis of earlier incidents of the infection had shown that the strain of the virus found in the affected persons in Kerala was similar to the strain found in the body of the fruit bats.

In the previous incidents of Nipah too, the infection was reported from places where there was presence of fruit bats. In 2018 and 2023, the cases were reported in the eastern hilly region of Kozhikode.