| Nipah virus outbreaks in Kerala | |
|---|---|
 An electron micrograph of the Nipah virus | |
| Disease | Nipah virus |
| Date | 2018, 2021, 2023, 2024 |
| Fatality rate | 89.4% (2018) |
There have been several outbreaks ofNipah virus inKerala, some of which have been traced tofruit bats. TheNIV Pune confirmed the first case of Nipah virus in Kerala in May 2018. A total of 21 Nipah virus infected individuals died between 2018 and 2024.
After Nipah virus outbreaks in India in 2001 and 2007 (both in theeastern state ofWest Bengal), an outbreak occurred inKerala in 2018.[1] The 2018 Kerala outbreak was traced tofruit bats in the area, was generally confined toKozhikode andMalappuram districts,[2][3] and claimed 17 lives.[4] The outbreak was declared over on 10 Jun 2018.[5] Another outbreak occurred in 2021, but was confined to the village of Pazhur in theChathamangalam gram panchayat of Kozhikode district. It claimed one life, on 5 Sept 2021. An outbreak began in Kozhikode district in Aug 2023, claiming two lives and infecting four other people by 16 Sept of that year.[6]
The outbreak'sindex case was reported at a sub-divisional hospital inPerambra,[7]Kozhikode district, on 2 May.[8] The patient[7] was brought to theGMCH Kozhikode for further treatment, but succumbed to the virus. His brother, Mohammed Salih, was admitted to Baby Memorial Hospital inKozhikode[9] with suspectedviral encephalitis. A team of doctors at the hospital suspected Nipah, since his symptoms were similar to those of his brother (who had died by then).
The index patient had passed the virus to 16 people at Medical College Hospital, and two more were later infected. There were 10 deaths in the first week they included nurse Lini Puthussery, who had treated the index patient before diagnosis.[10][11] The outbreak began in Kozhikode district, later spreading to the adjacent Malappuram district. Health advisories were issued for northern Kerala and the adjoining districts ofKarnataka, with two suspected cases detected inMangalore on 23 May 2018.[12]
Over 2,000 people in Kozhikode and Malappuram districts werequarantined and kept under observation during the outbreak.[13] To fight the infection, M 102.4 (a human monoclonal antibody undergoing clinical trials) was imported fromAustralia.[14] This was facilitated by Nipah researcher Christopher Broder.[15]
After the index patient died, 16 other affected patients succumbed to the disease; two recovered fully. The outbreak was declared over on 10 June 2018.[5]
Presence of the virus in patients was confirmed withRT-PCR tests conducted at the Manipal Institute of Virology and the National Virology Institute inPune.[16] Although the first set of samples did not detect the virus in bats,[17] later tests indicated that fruit bats in the area were the source of the virus.[18]
On 23 May 2018, the Kerala Health Department issued an advisory asking travelers to northern Kerala to be cautious.[19] Two days later, the Ministry of Health and Prevention of theUnited Arab Emirates advised postponing unnecessary travel to Kerala and avoiding its fruits and vegetables until the situation was under control.[20]
On 30 May 2018, construction began on theInstitute of Advanced Virology, Kerala,[21] in response to the outbreak.[22] Two days later, theThamarassery diocese in northern Kerala urged churches to stop placing communion on the tongue, postpone religious classes and avoid weddings, family gatherings and unnecessary travel until the viral spread was contained.[23]
Kerala's efforts to contain the outbreak under health ministerK. K. Shailaja, health secretaryRajeev Sadanandan[15][24] and the district collector were praised by many, including theKerala High Court[25] andRobert Gallo of the Institute of Human Virology inBaltimore.[26]
Lini Puthussery, a 28-year-old nurse at the Perambra Taluk hospital who died of the virus, was called a hero by doctors and on social media.[27] A note she had written to her husband, Sajish, was circulated on social media.[28] The Kerala Government Hospital Development Society (KGHDS) employees' union instituted an award in Puthussery's name to an outstanding person in the sector.[29] The Best Nurse in Public Service Award was instituted in memory of Puthussery.[30] Jim Campbell, director of the health workforce of theWorld Health Organisation, tweeted: "Remember them, lest we forget: Razan al-Najjar (Gaza); Lini Puthusserry (India), Salome Karwah (Liberia)".[31]
A 23-year-old student was diagnosed on 4 June 2019 inKochi.[32] Over 300 people were put under observation, but no further cases were reported. The student later recovered.[33] This is the fourth outbreak reported in India, with previous outbreaks in 2001 (45 deaths), 2007 (five deaths), and 2018 (17 deaths).[34][35]
The 2021 outbreak began with the death of a 12-year-old boy in Pazhur,Kozhikode district, on 5 September.[36][37] The outbreak was localized in the village, which is in theChathamangalamgram panchayat of the district, and claimed one life.[38][39][40][41] This was Kerala's third Nipah virus outbreak,[42][43] following outbreaks in 2018 and 2019. The central government rushed a team from theNational Centre for Disease Control to the state to provide technical support. Relatives of the dead boy and those involved in his treatment were placed underquarantine.[44][45][46][47][48]
Theindex case of the outbreak was reported at a private hospital in Kozhikode district on 5 September, when a 12-year-old boy from Chathamangalam died after testing positive forNipah virus infection.[49][50] The new Nipah infection, which spreads through thesaliva offruit bats, came three years after a previous outbreak which claimed 17 lives.[51][52][53][54] The presence of Nipah virus in the boy was confirmed byRT-PCR tests, and all three samples (plasma,serum andCSF) were found to be positive in tests at theNational Institute of Virology in Pune.[55]
Six cases and two deaths were reported in August and September 2023.[56][57][58][59] One of the victims died on 30 August and the other died in early September, both in Kozhikode district. Two family members of a victim tested positive and were hospitalized.[60]
Indian Health MinisterMansukh Mandaviya announced that the central government had dispatched a team of experts to Kerala to assess the situation and help the state government manage the outbreak. Kerala Health MinisterVeena George reported that tests had confirmed that the virus strain in the outbreak was identical to one previously found inBangladesh, and teams from theNational Institute of Virology inPune had established a mobile laboratory atKozhikode Medical College for virus testing and bat surveys. George said that 168 contacts of the two deceased patients were identified and underwent virus testing. The state government established a control room in Kozhikode for continuous monitoring, and health workers were instructed to adhere strictly to infection-control protocols. Seven villages in Kozhikode were declared as containment zones, and some schools and offices in the district were temporarily closed. Kerala Chief MinisterPinarayi Vijayan said that the state government treated the deaths seriously, and urged the public to wear face masks and visit hospitals only for emergencies.[61][60]
A 14-year-old boy fromPandikkad,Malappuram district died on 21 July 2024 at GMCH Kozhikode. He had exposure to hog plum fruit, although it was not certain if this was the vehicle that exposed him to the virus, and fruit bat activity existed in the area. The boy had initially been admitted to a hospital in Perinthalmanna for acute encephalitis. He was unable to receive a monoclonal antibody treatment because of his deteriorating condition by the time it arrived.[62][63] One more death was reported in Malappuram district during the month of September 2024. The person was a 24-year-old student who had come there from Bangalore.[63][64]
As of early June 2025, at least 425 people have been placed under observation inKerala amid a renewed Nipah virus scare. The districts of Palakkad, Malappuram, and Kozhikode have been put on high alert. In Palakkad, 61 of the 110 contacts identified are health workers; similarly, all 87 identified in Kozhikode are medical personnel. The Health Minister has advised psychological support for those under surveillance. A teenage girl from Makkaraparamba, Malappuram, succumbed to the virus on June 1, while a 38-year-old woman fromThachanattukara,Palakkad, remains critical at Moulana Hospital inPerinthalmanna. Health authorities continue to intensify containment efforts to prevent further spread.[65]
Virus, a 2019 Indian Malayalam medical thriller film co-produced and directed by Aashiq Abu and released on 7 June 2019, was based on the 2018 outbreak.[66]