Two instances of the lethal Nipah virus in India have prompted authorities in Thailand and Malaysia to enhance airport screening procedures to prevent the spread of the infection. Here’s a closer look at Nipah virus and the level of concern it warrants.
The Health Ministry of India confirmed on Tuesday the detection of two Nipah cases since December, with all identified contacts placed under quarantine and tested. While the ministry did not disclose specifics about the patients, it reported tracing 196 contacts, all of whom tested negative.
Nipah is a rare viral infection primarily transmitted from infected animals, particularly fruit bats, to humans. The World Health Organization notes that it can be asymptomatic but is often highly perilous, with a case fatality rate ranging from 40 to 75 percent based on the local healthcare system’s detection and management capabilities.
The virus was first identified in Malaysia in 1999, leading to small outbreaks almost annually, primarily in Bangladesh, with sporadic occurrences in India. According to the Coalition for Epidemic Preparedness Innovations, there have been 750 recorded cases to date, resulting in 415 fatalities.
Initially spreading through contact with sick pigs or contaminated tissues in Malaysia, Nipah now mostly spreads through contact with fruit bats, its natural hosts. Consumption of fruit or products contaminated with urine or saliva from infected fruit bats is identified as a common source of infection. Human-to-human transmission has been documented, typically through close contact with an infected patient or caregivers.
The symptoms of Nipah, such as fever, headaches, and muscle pain, are non-specific and may be mistaken for other illnesses. Subsequent neurological signs may indicate acute encephalitis, leading to severe respiratory issues and, in severe cases, seizures progressing to a coma. While most individuals recover fully, some may experience long-term neurological complications.
Despite its high fatality rate, Nipah has not exhibited increased transmissibility among humans or global spread potential. Nevertheless, it remains a significant public health concern, particularly in regions with frequent outbreaks, often necessitating mass culling of susceptible farm animals. While global spread is deemed unlikely, the long incubation period of the virus may render airport screening ineffective.
Currently, there are no approved vaccines or treatments for Nipah. Various candidates, including one developed by Oxford University scientists, are undergoing testing, with their vaccine utilizing technology similar to that of COVID-19 vaccines. This Nipah vaccine entered Phase 2 trials in Bangladesh in December, in partnership with the International Centre for Diarrhoeal Disease Research and funding from the Coalition for Emergency Preparedness Innovations.
