Nipah Virus: What You Need to Know

By Erin Currie, CRTA intern; teaser image courtesy of National Geographic
A fruit bat

Nipah virus is a zoonotic virus that is responsible for multiple outbreaks across Asia, including in Malaysia, Singapore, and India. The virus has been added to the World Health Organization’s 2018 Priority Diseases List, which indicates a pressing need for further research and development.

Nipah is difficult to diagnose due to its large array of signs and symptoms, which range from fever and sore throat to encephalitis and seizures. The incubation period is believed to last 4 to 14 days; however, it has been reported to last as long as 45 days.

According to the World Health Organization, an estimated 40–75 percent of cases result in fatalities, depending on the outbreak and the local capabilities and resources.  Laboratory tests are performed in order to confirm diagnosis, which can be made during either the acute or convalescent phases of the disease by using real-time polymerase chain reaction on throat or nasal swabs or by antibody detection.

The natural host of Nipah virus is fruit bats of the Pteropodidae family, although pigs can also carry the disease. Transmission to humans occurs through direct contact with infected bats or pigs, ingestion of raw date palm sap, or contact with other Nipah-infected humans.

Virologists studying Nipah have discovered that the virus latches on to surface cell proteins ephrin-B2 and ephrin-B3, which are located on nerve cells and endothelial cells that line blood and lymph vessels. The virus then targets the respiratory system before spreading to the nervous system and brain.

While the only currently available treatment is supportive care in a hospital, researchers are in the process of doing clinical trials on potential drugs and care treatments. And even though there is no vaccine, travelers can take precautions to reduce their susceptibility. The U.S. Centers for Disease Control and Prevention (CDC) suggests avoiding exposure to sick pigs and bats in endemic areas as well as not drinking raw date palm sap.

Since human-to-human transmission is possible, the CDC also recommends reducing close, unprotected physical contact with infected people. Hand washing, gloves, and protective equipment are also advised when in healthcare settings or when handling infected animals.