Kerala battles Nipah again

Within a year of promptly identifying and effectively containing its first-ever outbreak of the deadly Nipah virus, which had claimed 17 lives, Kerala is battling the deadly pathogen once again.

A 23-year old student admitted to a private hospital in Ernakulam district on May 30 with complaints of “fever, slurring of speech and gait imbalance” for over a week, tested positive for Nipah viral encephalitis. State Health Minister K.K. Shailaja confirmed the news to the media on June 4, quoting final test results from the National Institute of Virology, Pune. 

Four other people, including a fellow student and three hospital staff members who gave care to the young man, have also shown symptoms of possible infection and are under observation, the Minister said.

“There is no cause for concern as the State health department had made elaborate arrangements for managing and containing an outbreak as soon as it was suspected as a case of Nipah infection. We did not wait for confirmation from the NIV to put in place emergency response measures,” the Minister said.

The 23-year-old student, who hails from North Paravur in Ernakulam district, was stated to be “clinically stable, slowly improving and his fever is subsiding”, according to a press statement issued by the private hospital where he is being treated.

The young man is a student at a college in Thodupuzha in Idukki district and travelled to Trissur recently with a group of students for an internship programme in a private company.

State authorities have identified all those who came in some form of contact with the young man since he developed signs of fever. A list of 311 people has been prepared for daily monitoring of their health status. The four who came in close contact with the student and showed signs of fever and sore throat were moved to an isolation ward at the Medical College Hospital at Kalamasseri. A fifth person, who had no contact with the “index patient’, too is under observation at the isolation ward.

Nipah virus encephalitis is a highly infectious disease spread by secretions of infected bats. Human Nipah Virus (NiV) is an RNA virus that has the potential for high rates of mutations and is hence highly pathogenic. It can spread to humans through contaminated fruit, infected animals or close contact with infected humans. Outbreaks are known to occur during December-May (winter to spring) season.

The virus is highly virulent and lethal and the infection causes severe respiratory illness, with symptoms including cough, headache, fever, altered mental status, severe weakness, vomiting, muscle pain, diarrhoea, and eventually encephalitis (inflammation of the brain), seizures and coma.

The virus does not become infectious immediately after it enters a host body. Its incubation period is said to be between four and 21 days.  The case fatality rate (or the proportion of deaths within a population of people with the infection) is estimated to be 40 to 75 per cent or higher. But this can vary depending on local capabilities for epidemiological surveillance and clinical management.

There is as yet no known treatment or approved vaccine available against the virus and hospitals can only provide intensive supportive care, including for respiratory and neurological complications. At her mid-day press briefing on June 5, Minister Shailaja said the condition of all five people in the isolation ward appeared to be improving. Their blood samples were being sent to the NIV and the results were awaited within two days.  The Minister said that Kerala had enough stock of required medicines, including Ribavirin (that is reported to be of use in reducing mortality among patients with encephalitis caused by the Nipah virus disease.)

After the first Nipah outbreak in 2018, during which 17 of the 18 infected people had died, a large majority of them getting the infection through people to people contact in hospital settings, the State had contacted a network of international experts and groups to find out the best possible way to respond to the crisis. It had also considered the use of experimental molecules that were found to be potentially effective against the Nipah virus. One of them, a human monoclonal antibody called “m102.4”, which had proved successful against Nipah and Hendra viruses in animal tests in Australia, was therefore obtained by the Government of India. But since the outbreak was by then brought under control, the experimental molecule was not used then. It has now been flown to Kochi from NIV, Pune, for use if needed, with the approval of relatives of patients. The Central government has also sent a team of experts to help the State authorities in managing the crisis, including contact tracing and review of isolation and treatment facilities and to implement protocols for containing the outbreak.

The source of the infection is yet to be traced and the State government is pursuing all options, including a thorough review of the deaths registered in the past three weeks, to identify any case of death with symptoms of Nipah infection.