- Till today, there is no effective vaccine available for nipah virus
- The virus is capable of causing deadly outbreaks with mortality rates approaching 40% to 90%
- The virus has spread thousands of kilometres into Bangladesh & India
A deadly virus called Nipah carried by bats has already caused human outbreaks across South and South East Asia and has “serious epidemic potential”, global health and infectious disease specialists said on Monday.
The virus, identified in 1999 in Malaysia and Singapore, has sparked outbreaks with mortality rates of between 40% and 90% and spread thousands of kilometres to Bangladesh and India — yet there are no drugs or vaccines against it, they said.
“Twenty years have passed since its discovery, but the world is still not adequately equipped to tackle the global health threat posed by Nipah virus,” said Richard Hatchett, chief executive of the CEPI Coalition for Epidemic Preparedness Innovations, which is co-leading a Nipah conference this week in Singapore.
CEPI, a partnership between disease experts, and public, private, philanthropic, and civil organisations, was set up in 2017 to try to speed up the development of vaccines against newly emerging and unknown infectious diseases.
Among its first disease targets is Nipah, a virus carried primarily by certain types of fruit bats and pigs, which can also be transmitted directly from person to person as well as through contaminated food.
Within two years of being first discovered, Nipah had spread to Bangladesh, where it has caused several outbreaks since 2001. A 2018 Nipah outbreak in Kerala killed 17 people.
“Outbreaks of Nipah virus have so far been confined to South and Southeast Asia, but the virus has serious epidemic potential, because Pteropus fruit bats that carry the virus are found throughout the tropics and sub-tropics, which are home to more than two billion people,” Hatchett said.
He said since Nipah can also pass from person to person, it could, in theory, also spread into densely populated areas too.
The two-day Nipah conference, the first to focus on this deadly virus, is being co-hosted by CEPI and the Duke-NUS Medical School in Singapore and starts on Monday.
“There are currently no specific drugs or vaccines for Nipah virus infection, even though the World Health Organization has identified (it) as a priority disease,” said Wang Linfa, a Duke NUS professor and co-chair the conference. He hoped the meeting would stimulate experts to find ways of finding Nipah.
The risk of exposure is high for hospital workers and caretakers of those infected with the virus. In Malaysia and Singapore, Nipah virus infection occurred in those with close contact to infected pigs. In Bangladesh and India, the disease has been linked to consumption of raw date palm sap (toddy) and contact with bats respectively.
Prevention of Nipah virus infection is important since there is no effective treatment for the disease. The infection can be prevented by avoiding exposure to bats in endemic areas and sick pigs. Drinking of raw palm sap (palm toddy) contaminated by bat excrete, eating of fruits partially consumed by bats and using water from wells infested by bats should be avoided. Bats are known to drink toddy that is collected in open containers, and occasionally urinate in it, which makes it contaminated with the virus. Surveillance and awareness are important for preventing future outbreaks. The association of this disease within reproductive cycle of bats is not well studied. Standard infection control practices should be enforced to prevent nosocomial infections. A subunit vaccine using the Hendra G protein was found to produce cross-protective antibodies against henipavirus and nipavirus has been used in monkeys to protect against Hendra virus, although its potential for use in humans has not been studied.
Currently there is no specific treatment for Nipah virus infection as of 2019. The mainstay of treatment is supportive care.