Nipah Virus Which Caused 'Mystery' Deaths in Kerala Yet to Get a Cure, is Spread by Bat Species

New Delhi/Thiruvananthapuram: Three of the 10 deaths caused by a mystery viral fever in Kerala’s Kozhikode were confirmed to have been caused by the Nipah virus, the National Institute of Virology (NIV) in Pune has said.

Late on Sunday, Union Health Minister JP Nadda sent the Director of National Centre for Disease Control (NCDC) to visit Kerala's Kozhikode district to assist the state government.

According to NIV director Dr Devendra T Mourya, the test results suggest a “focal outbreak" of the Nipah virus. The report has been submitted to Dr Balram Bhargava, the Director General of the Indian Council of Medical Research (ICMR), NIV’s parent body.

The Nipah virus is a lesser studied virus, which the World Health Organisation calls “a newly emerging zoonosis that causes severe disease in both animals and humans." There are no known drugs or vaccines to treat it.

Speaking to News18, Mourya said the virus has been causing “focal outbreaks in very rare situations among humans who accidentally come into contact (with the virus) from bats."

But not all bats are infected with the Nipah virus. The Pteropus species is a “known reservoir", but even among this species, very few bats are carriers and capable of secreting this virus.

Five of the victims, including three of a family from Kozhikode, suffered an “acute onset" of symptoms, said Dr. Ajit Bhaskar, a pulmonologist from the city and the Indian Medical Association (IMA) state chairman for ventilator and cardiac life support.

Among the victims is 31-year-old Lini Puthussery, a nurse at the Perambra Taluk Hospital who had treated another fatality. Puthussery breathed her last on Sunday night. Fearing that her body may still be infected, the state health authorities conducted the cremation within hours, without releasing the body to her family.

In Kozhikode, seven persons remain under intensive care after it was confirmed that they contracted the virus. The condition of two is said to be critical. At least 25 people who had come in contact with the victims are under observation. A special ward and a control room have also been set up. The patients are currently being treated at the Kozhikode Medical College, Baby Memorial Hospital and at the Amrita Institute of Medical Sciences in Kochi.

The first fatalities in Kozhikode were two siblings in Changorath Panchayat of Kozhikode. Twenty-three-year-old Sabith's death on May 5 did not initially raise alarms, but when his 26-year-old brother Salih died on May 18, the situation took a serious turn. Their aunt, 50-year-old Miriam died a few days later.

Four people have died in neighbouring Malappuram district from similar symptoms, although the cause has not been officially confirmed.

After an incubation period of seven to 14 days, the victims developed a fever, sudden onset of breathlessness, low blood pressure and meningitis. Even those who were put on ventilators did not survive.

The question for the medical community, said Bhaskar, is how this happened. This is what the IMA and the district administration was left grappling with in a series of meetings on Sunday.

Among the questions to be considered is whether the virus emerged after recent contact between people and bats? Did it happen, as one of the standing theories is, through people eating fruits that bats had already bitten into? Or, was the virus always present and its symptoms and cases lost among those infected with dengue?

According to Bhaskar, the virus may be have been identifiable for the first time as the cases emerged before monsoon and the onset of dengue.

The Nipah virus symptoms bear similarity to vector-borne viral diseases and these patients were tested for all others, including dengue and H1N1, before someone thought of Nipah.

The virus was discovered first in Malaysia in 1998 and the most recent outbreak was in Bangladesh in 2004.

There are no known antivirals, though some doctors, said Bhaskar, were thinking of trying those used for H1N1. At the moment, doctors aren’t even sure if the deaths were caused by the virus alone, or if exacerbated co-existing conditions.

Though it is not thought to be airborne, rather caused by bodily contact, doctors are worried about it spreading to other parts of the country as people travel.