Two instances of the lethal Nipah virus in India have prompted authorities in Thailand and Malaysia to enhance airport screening measures to prevent the spread of the infection. The Health Ministry of India reported on Tuesday that two cases of Nipah had been identified since December, with all close contacts placed under quarantine and tested. Although specific patient details were not disclosed, the ministry mentioned that 196 contacts were traced, and all tested negative.
Nipah is a rare viral infection that primarily transmits from infected animals, particularly fruit bats, to humans. While it can be asymptomatic, Nipah is highly dangerous, with a case fatality rate ranging from 40 to 75 percent, depending on the local healthcare system’s capabilities for detection and management, as per the World Health Organization. Although human-to-human transmission is possible, it is not easily spread, and outbreaks are typically limited in size and scope.
The first known case of Nipah was reported in Malaysia in 1999, with subsequent small outbreaks occurring nearly every year, primarily in Bangladesh. India also experiences sporadic outbreaks. To date, there have been a total of 750 recorded cases, resulting in 415 fatalities, according to the Coalition for Epidemic Preparedness Innovations.
Initially spreading through direct contact with sick pigs or contaminated tissues in Malaysia, Nipah now commonly transmits through contact with fruit bats, its natural host. Consumption of contaminated fruit or fruit products, such as raw date palm juice, has been identified as a primary mode of infection. Human-to-human transmission occurs mainly through close contact with an infected patient and their family or caregivers.
Symptoms of Nipah include non-specific signs like fever, headaches, and muscle pain, which can progress to neurological symptoms indicating acute encephalitis or severe respiratory problems. While the disease carries a high fatality rate, it has not demonstrated increased human-to-human transmission or global spread potential. However, Nipah remains a significant public health concern, particularly in regions prone to outbreaks, leading to the culling of susceptible farm animals like pigs.
Currently, there are no approved vaccines or treatments for Nipah, although multiple candidates are undergoing testing. Oxford University scientists have developed a vaccine utilizing similar technology to COVID-19 vaccines, which entered Phase 2 testing in Bangladesh in December with support from the Coalition for Emergency Preparedness Innovations.