Q&A: What should you know about the deadly virus causing international concern?

Health authorities in India say they have contained a potential outbreak of a bat-borne virus with no approved vaccine or cure. With a fatality rate between 40% to 75%, authorities in several Asian countries are stepping up screening measures, including temperature checks for airport passengers to prevent further spread.

The Nipah virus can be transmitted from animals to humans – especially from fruit bats and pigs – and between humans, according to the World Health Organization. 

UVA Today checked in with infectious disease and international health expert Dr. William Petri, the University of Virginia’s Wade Hampton Frost Professor of Medicine and vice chair for research in the Department of Medicine, to learn more about the virus.

Dr. William Petri

Dr. William Petri is the Wade Hampton Frost Professor of Medicine and vice chair for research in the UVA Department of Medicine. (University Communications photo)

Q. What is Nipah, and where does it come from?

A. Nipah killed the character Gwyneth Paltrow was playing in the movie “Contagion!” The Nipah virus is an RNA virus, like the COVID-19 virus, but it is similar to rabies and Ebola.

In Bangladesh, where I do maternal and child health research, the virus is endemic, transmitted by ingestion of raw date palm sap. Date palm sap is not dissimilar to maple syrup. It’s harvested not by tapping the trunk of the tree, but by cutting the fruit stalks of the tree.

Fruit bats are the reservoir of the virus, and the bats, by feeding on the date palm sap, contaminate it with the Nipah virus through their feces, saliva or urine.

About a week after ingestion of the contaminated date palm sap, infected people get fever and flu-like symptoms, followed by headache and confusion as the virus invades the brain. It causes an inflammation of the brain called encephalitis that, in more than half of infected people, leads to coma and death.

Q. Why is it so dangerous?

A. Part of the reason that it is so deadly is that it enters and replicates in many different cells, gaining entry through what are called ephrin receptors that … regulate cell movement. Cells in the body infected by Nipah include the epithelial cells lining the lung airways, the endothelial cells that line blood vessels, and neurons.

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Q. How serious is the current outbreak?

A. This year, two nurses in West Bengal, near Kolkata, India, have contracted Nipah, and one is in critical condition with a coma. They were both caring for a patient hospitalized over New Year’s with fever and respiratory distress, who died before Nipah was tested for. They are both being treated with remdesivir.

While person-to-person transmission is not as common, it is known to occur especially in hospital settings via respiratory droplets or secretions. More than 100 exposed people, mostly from the same hospital, are quarantining at home in an attempt to prevent the spread.

Q. What is the likelihood of Nipah coming to the U.S.?

A. The risk is Nipah mutating to better person-to-person transmission, so it’s an unknown. Incubation is one week, so someone could unknowingly bring it here.

Q. How is the virus treated?

A. Experimental treatments that are unproven include remdesivir, used in treating COVID-19, which inhibits the viral RNA (enzymes), and monoclonal antibodies that bind to the viral spike protein and block viral entry into human cells.

There are several vaccines that have been developed against Nipah based on the virus spike or fusion protein, but they have yet to be tested during an outbreak to see how well they work.

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Bryan McKenzie

Assistant Editor, UVA Today Office of University Communications