Nipah in Kerala: last year, this year, what next

Nipah virus: As of now, scientists feel the current outbreak is likely localised, like last year’s. People who have had close contact with a patient are considered to be at potential risk.

Written by Anuradha Mascarenhas , Edited by Explained Desk

Pune | Updated: June 5, 2019 12:10 AM IST

4 min read

Explained: Nipah makes a comeback in Kerala; all you need to know

Bats in their abode at Gujarat College in Ahmedabad come to light after Nipah virus deaths emerge from Kerala. express photo by javed raja 22-5-2018 *** Local Caption *** Bats in their abode at Gujarat College in Ahmedabad come to light after Nipah virus deaths emerge from Kerala.

The natural host of the Nipah virus is fruit bats of the Pteropodidae family and Pteropous genus. (Express File Photo: Javed Raja)

A youth from Ernakulam district in Kerala has tested positive for the Nipah virus infection, a year after a similar outbreak in the state had claimed 17 lives. The infected patient this year has survived for more than 10 days now, and health authorities are hopeful that this latest outbreak would be contained soon. The infected patient has been isolated, and everyone he had potential contact with in the last few days is being screened.

The virus

Nipah virus causes a so far incurable infection in human beings, which can sometimes be fatal. The infection is generally transmitted from animals to human beings, mainly from bats and pigs. Human-to-human transmission is also possible, and so is transmission from contaminated food.

The natural host of the virus are fruit bats of the Pteropodidae family and Pteropous genus, widely found in South and South East Asia. However, the actual source of the current infection is not yet known, said Dr D T Mourya, director of Pune-based National Institute of Virology (NIV), which is at the forefront of efforts to contain the virus. Scientists are currently working on finding the epidemiological link of the outbreak.

First identified in 1999 in Malaysia, Nipah virus infections have been detected quite frequently in Bangladesh. There have been a few incidents of infection in India earlier, apart from last year’s outbreak in Kerala.

Patients either show no symptoms of the infection, thereby making it difficult to detect, or develop acute respiratory problems, or encephalitis that often becomes fatal.

The World Health Organization (WHO) says the infection has been found to be fatal in 40% to 75% of the infected patients. There is no treatment available as of now, either for humans or animals, nor any vaccine.

The previous outbreak

Last year’s outbreak was confined to two districts, Kozhikode and Malappuram. Studies by NIV have revealed that a particular kind of fruit bat, Pteropus spp, was most likely the source of human infection in 2018. Research led by NIV scientist Pragya Yadav suggested that this particular strain might have been circulating in the local bat population.

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The newly detected case in Kerala, authorities believe, could actually be a result of intensified preventive and containment efforts after last year’s outbreak. There has been an increased awareness and vigilance in the community. According to Dr Mourya, this helped in early detection this time.

Not just in Kerala

Nipah virus has been found in other parts of India earlier. The first outbreak was in 2001 in Siliguri, where more than 30 people were hospitalised with suspected infection. Another outbreak happened in 2007 in Nadia of West Bengal. Again, over 30 cases of fever with acute respiratory distress and/or neurological symptoms were reported, five of which turned out to be fatal. Last year, after the outbreak in Kerala, doctors tested samples from suspected cases in Karnataka, Telangana and Maharashtra. All of them tested negative.

Can it spread?

As of now, scientists feel the current outbreak is likely localised, like last year’s. So far only one suspected sample has tested positive. More people showing symptoms are being screened and so are people in physical contact with them.

A study by NIV, published last month in the journal Emerging Infectious Diseases, reported that the risk for asymptomatic infections (in which the infected person does not show overt symptoms) was higher among people with a history of exposure to body fluids of infected patients as compared to those who only had physical contact with the patient. After the study, the NIV advised extreme care for healthcare workers and caregivers — double gloves, fluid-resistant gown, goggles, face shields, closed shoes and similar other protective gear — and a limited number of visitors to the patient.

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People who have had close contact with a patient are considered to be at potential risk. These include people who have slept in the same household , have had direct physical contact either with the patient or a deceased who had an infection, or have touched the blood or other body fluids (saliva, urine, sputum) of the patient during illness.

Anuradha Mascarenhas

Anuradha Mascarenhas is a Senior Editor at The Indian Express, based in Pune. With a career spanning three decades, she is one of the most respected voices in Indian journalism regarding healthcare, science and environment and research developments. She also takes a keen interest in covering women's issues . Professional Background Education: A gold medalist in Communication and Journalism from Savitribai Phule Pune University and a Master’s degree in Literature. Author: She authored the biography At The Wheel Of Research, which chronicles the life and work of Dr. Soumya Swaminathan, the former Chief Scientist at the WHO. Key Focus: She combines scientific accuracy with storytelling, translating complex medical research into compelling public and human-interest narratives. Awards and Recognition Anuradha has won several awards including the Press Council of India's national award for excellence in journalism under the gender based reporting category in 2019 and the Laadli Media award (gender sensitivity -2024). A recipient of the Lokmat journalism award (gender category-2022), she was also shortlisted for the RedInk awards for excellence in journalism-2021. Her debut book At The Wheel Of Research, an exclusive biography of Dr Soumya Swaminathan the inaugural chief scientist of World Health Organisation was also nominated in the Popular Choice Category of JK Paper AUTHER awards. She has also secured competitive fellowships including the Laadli Media Fellowship (2022), the Survivors Against TB – New Research in TB Media Fellowship (2023) and is part of the prestigious 2025 India Cohort of the WomenLift Health Leadership Journey.” Recent Notable Articles (Late 2025) 1. Cancer & Specialized Medical Care "Tata Memorial finds way to kill drug-resistant cancer cells" (Nov 26, 2025): Reporting on a breakthrough for triple-negative breast cancer, one of the most aggressive forms of the disease. Discipline, diet and purpose; How a 97-year-old professor defies ageing'' (Nov 15, 2025) Report about Prof Gururaj Mutalik, the first Head of Department at Pune's B J Government Medical College who at 97 credits his longevity to healthy habits and a strong sense of purpose. 2. Environmental Health (The "Breathless Pune" Series) Long-term exposure even to 'moderate' air leads to chronic heart, lung, kidney issues" (Nov 26, 2025): Part of an investigative series highlighting that even "safe" pollution levels are damaging to vital organs. "For every 10 µg/m3 increase in PM2.5 level, there was 6-8% jump in medicine sales" (Nov 23, 2025): Using commercial data to prove the direct link between air quality and respiratory illnesses in Pune. 3. Lifestyle & Wellness News "They didn't let cancer, diabetes and heart disease stop them from travelling" (Dec 22, 2025): A collaborative piece featuring survivors who share practical tips for traveling with chronic conditions. At 17, his BP shot up to 200/120 mmHG; Lancet study flags why child and teen hypertension doubled between 2000 and 2020'' (Nov 12,2025)--A report that focusses on 17-year-old-boy's hypertensive crisis and reflects the rising global trend of high blood pressure among children and adolescents. 4. Scientific Recognition & Infrastructure For promoting sci-comm, gender diversity: IUCAA woman prof highlighted in Nature" (Nov 25, 2025): Covering the global recognition of Indian women scientists in gender studies and physics. Pune researchers find a spiral galaxy like the Milky Way from early universe'' (December 3, 2025)- A report on how Indian researchers discovered a massive galaxy that existed when the universe was just 1.5 billion years old , one of the earliest to have been observed so far. Signature Beat: Health, Science & Women in Leadership Anuradha is known for her COVID-19 reportage, where she was one of the first journalists to provide detailed insights into the Covishield and Covaxin trials. She has a dedicated interest in gender diversity in health and science, often profiling women researchers who are breaking the "leaky pipeline" in STEM fields. Her writing style is scrupulous, often featuring interviews with top-tier scientists and health experts from various institutions. ... Read More

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