Doctors' bid to chart nipah spread in Kerala
New Delhi: Doctors suspect a 26-year-old was the first patient from whom the nipah virus spread to others during the current outbreak in Kozhikode district of Kerala.
"We suspect that the index case (first patient) for this outbreak is a 26-year-old man who died on May 5," Jayasree Vasudevan, the district medical officer, said.
The man's brother also developed the illness and died on May 18, while an older female relative died on May 19, she said.
Kerala health minister K.K. Shylaja has said the father of the two brothers is being treated and eight others are under observation in hospital.
A nursing assistant who had treated three infected people died on Monday morning, a PTI report said. Five other people have died after high fever and similar symptoms in Kozhikode and neighbouring Malappuram, it added. But it is unclear whether any of the six were infected by nipah.
Human-to-human transmission, particularly among family members and health-care staff with close contact with patients, has been documented in India and Bangladesh.
Doctors lack any specific treatment or a vaccine against nipah and can provide only supportive therapy while waiting for the patient's immune system to fight the virus.
Health experts say the first major outbreak of the virus in India had occurred in Siliguri district of Bengal in 2001, with 45 of the 66 people infected dying. In an outbreak in Nadia in 2007, all five infected patients died. (See Chart)
Bangladesh had recorded a series of nipah virus outbreaks almost every year between 2001 and 2013. Disease investigators have attributed several of those outbreaks to the drinking of raw date-palm sap contaminated with saliva or urine from the fruit bat that contained the nipah virus.
The nipah virus was first isolated after outbreaks of encephalitis and respiratory infections among farmers and people with close contact with pigs in Malaysia and Singapore in 1999.
The investigations revealed that the pigs had been intermediate hosts during the spread of the virus from fruit bats to humans.
Scientists from India's High Security Animal Disease Laboratory in Bhopal had said in a 2013 review of the nipah infection that the transmission patterns in Bangladesh and India were different from those in Malaysia and Singapore.
In India and Bangladesh, the virus appeared to have jumped directly from fruit bats to humans.