The death toll in the Nipah virus outbreak in north Kerala has touched 11, spreading panic across the state. The latest death is that of a nurse who treated patients of the outbreak at Perambra Taluk Hospital. Perambra, about 40 km from Kozhikode city, is the epicentre of the outbreak. While seven deaths have been reported from Kozhikode, four people who showed similar symptoms of viral encephalitis have died in Malappuram.
The National Institute of Virology in Pune has attributed three deaths in Changaroth village of Perambra to the virus. All three were members of the same family. At least 10 people are undergoing treatment at various hospitals across Kozhikode.
Nipah Virus is an emerging infectious disease that broke out in Malaysia and Singapore in 1998 and 1999. It first appeared in domestic pigs and has been found among several species of domestic animals including dogs, cats, goats, horses and sheep. The infection is also known to affect human beings.
The organism which causes Nipah Virus encephalitis is an RNA or Ribonucleic acid virus of the family Paramyxoviridae, genus Henipavirus, and is closely related to Hendra virus.
Nipah virus infection gets its name from the village in Malaysia where the person from whom the virus was first isolated succumbed to the disease. The virus has been listed in the World Organisation for Animal Health (OIE) Terrestrial Animal Health Code and must be reported to the OIE (OIE Terrestrial Animal Health Code).
How does Nipah spread ?
The disease spreads through fruit bats or ‘flying foxes,’ of the genus Pteropus, who are natural reservoir hosts of the Nipah and Hendra viruses. The virus is present in bat urine and potentially, bat faeces, saliva, and birthing fluids. Presumably, the first incidence of Nipah virus infection occurred when pigs in Malaysian farms came in contact with the bats who had lost their habitats due to deforestation. Furthermore, transmission between farms may be due to fomites – or carrying the virus on clothing, equipment, boots, vehicles.
Nipah Virus, which is a zoonotic disease, was known to affect humans in Malaysia and Singapore after coming in direct contact with the excretions or secretions of infected pigs. Reports from outbreaks in Bangladesh suggest transmission from bats in the process of drinking raw palm sap contaminated with bat excrement or climbing trees coated in the same.
In Bangladesh and India, there have been reports of possible human-to-human transmission of the disease. Therefore, precautions are necessary for hospital workers in charge of taking care of the infected patients. Precautions should also be taken when submitting and handling laboratory samples, as well as in slaughterhouses.
Symptoms of the infection
Typically, the human infection presents as an encephalitic syndrome marked by fever, headache, drowsiness, disorientation, mental confusion, coma, and potentially death. During the outbreak in Malaysia, up to 50 per cent of clinically apparent human cases died. There is no specific treatment for Nipah Virus. The primary treatment for human cases is intensive supportive care.
