Nipah virus detected in India

LONDON, Jan 28 (Reuters): Two cases of the deadly Nipah virus in India have prompted authorities in Thailand and Malaysia to step up airport screening to prevent the spread of the infection. But what is Nipah virus, and how worried should people be?

Nipah is a rare viral infection that spreads largely from infected animals, mainly fruit bats, to humans. It can be asymptomatic but it is often very dangerous, with a case fatality rate of 40per cent to 75per cent, depending on the local healthcare system's capacity for detection and management, the World Health Organization says.

However, while it can also spread from person to person, it does not do this easily, and outbreaks are usually small and fairly contained, according to experts and the European Centre for Disease Prevention and Control. Candidate vaccines are under development, although none have been approved yet.

Nipah was first identified in Malaysia in 1999. Since then, there have been small outbreaks almost every year, mostly in Bangladesh. India also sees sporadic outbreaks. According to the Coalition for Epidemic Preparedness Innovations, a group that tracks emerging disease threats and funds the development of medical tools to protect against them, as of December 750 cases had been recorded in all, and 415 of the patients died.

When first identified in Malaysia, Nipah spread largely through direct contact with sick pigs or contaminated tissues. Since then, it more commonly spreads from contact with what scientists say is its natural host: fruit bats.

More specifically, the consumption of fruit or fruit products - like raw date palm juice - containing urine or saliva from infected fruit bats has been the most likely source of infection, the WHO says. Human-to-human spread has been found, mainly after close contact between a sick patient and their family or caregivers.

The initial symptoms of Nipah such as fever, headaches and muscle pain are not specific and can be confused with other diseases.