The rare but deadly Nipah virus has recently emerged in southern Indian State of Kerala, killing at least 12 people including a nurse and causing more than 25 others to be hospitalized.
Nipah virus (NiV) infection is a newly emerging zoonosis that causes severe disease in both animals and humans. The natural host of the virus are fruit bats of the Pteropodidae Family, Pteropus genus, according to World Health Organisation.
NiV was first identified during an outbreak of disease that took place in Kampung Sungai Nipah, Malaysia in 1998.
NiV is on the WHO’s priority list of emerging diseases that could cause a global pandemic, alongside Zika and Ebola.
NiV infection in humans has a range of clinical presentations, from asymptomatic infection to acute respiratory syndrome and fatal encephalitis.
Those infected suffer a quick onset of symptoms, including fever, vomiting, disorientation, mental confusion, encephalitis and — in up to 70 percent of cases, depending on the strain — ultimately death.
NiV is also capable of causing disease in pigs and other domestic animals.
There is no vaccine for either humans or animals. The primary treatment for human cases is intensive supportive care only.
How is the NiV spread?
Several species of fruit bats that live throughout Asia carry Nipah. During outbreaks in Bangladesh from 2001 to 2007 — most people contracted the virus by drinking raw date palm sap that virus-carrying fruit bats had also sipped and contaminated.
Bats can also transmit NiV to pigs and other livestock, which can then pass the infection onto humans. And humans can spread the virus through saliva and possibly other bodily fluids.
NiV and its viral cousin Hendra latch onto a proteins called ephrin-B2 and ephrin-B3 on the surface of nerve cells and the endothelial cells lining blood and lymph vessels, researchers have found. NiV can also invade lung and kidney cells.
Most patients who die succumb to an inflammation of blood vessels and a swelling of the brain that occurs in the later stages of the disease.