Genotype I strain of Nipah virus variant likely present in Kerala

The strain of Nipah virus variant present in Kerala is likely to be genotype I, according to people familiar with the matter. Nipah has three genotypes— Malaysia M genotype; Bangladesh B genotype; India I genotype. In India, two genotypes are commonly found, Bangladesh B and India I, and the latter is the one that has been found in bats and humans in Kerala, according to an expert from the Indian Council of Medical Research’s apex virology in National Institute of Virology (NIV) in Pune, who spoke on condition of anonymity.

Read here: Nipah virus: Past outbreaks, scrutiny helped in case detection

Nipah virus (NiV) is a highly pathogenic virus that causes fatal encephalitis—swelling of the brain— and acute respiratory distress in humans.

The initial outbreak of NiV infection, resulting in severe encephalitis, occurred among the pig farmers in Malaysia and Singapore in 1998-1999; relatively small, sporadic outbreaks among humans have occurred in Bangladesh and India since 2001, according to several research papers published on the viral disease.

The virus is transmitted to humans by direct contact with the respiratory secretions or body fluids of infected animals, such as bats and pigs, or by consumption of contaminated fruits or palm sap. Both animal-to-human and human-to-human transmission have been documented in several research papers. The main reservoir for NiV is believed to be fruit bats of the genus Pteropus.

“With five positive cases reported already from the state of Kerala and several suspected cases under observation currently, this could well be one of the biggest Nipah outbreaks in India since 2001, even though the central and state government both are making efforts to contain the spread of infection,” said a senior government official, requesting anonymity. According to research papers, of some 66 probable cases, 45 deaths were reported in the 2001 outbreak.

Minister of state for health, Bharati Pravin Pawar, on Thursday reviewed the situation at NIV.

“Visited ICMR-NIV, Pune and held a review meeting in the context of current Nipah Virus outbreak reported in Kozhikode, Kerala. GoI under the visionary leadership of Hon’ble PM Shri @narendramodi ji and under guidance of Hon’ble HFM Dr. @mansukhmandviya ji is continuously monitoring the situation and necessary steps for prevention of spread are being taken,” tweeted Pawar after the review. Since 2015, the disease has been enlisted as a priority disease by World Health Organization (WHO).

India has witnessed at least five outbreaks since 2001, from West Bengal, and Kerala, with the latest being the fifth. The first was in Siliguri, West Bengal; the other four have been in Kerala.

According to NIV researchers who authored the paper, Nipah Virus Outbreak in Kerala State, India Amidst of COVID-19 Pandemic, published in Frontiers last year, since 2010, NIV has taken up the surveillance of the Nipah virus in bat populations across the country. During this, the presence of the virus was detected among bats from Maynaguri, West Bengal in 2010 and Cooch Bihar district, West Bengal, and Dhubri district, Assam in 2015.

Read here: Covid era-like containment zones back in Kerala as Nipah resurfaces

There is no specific treatment or a vaccine to prevent the disease. “Effective containment is the only possible solution with isolating suspected cases, use of personal protective equipment for health care workers, and implementing infection control policies in hospitals. Surveillance also needs to be strengthened,” said the NIV official cited above.