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The deadly Nipah virus may be on the verge of ravaging parts of South and Southeast Asia as doctors, researchers, and epidemiologists met this week in Singapore to figure out what to do about it.
Nipah virus, first identified in 1999 among Malaysian pig farmers, has no approved vaccine or cure, and is often deadly to humans. That's why the international disease prevention organization, the Coalition for Epidemic Preparedness Innovations (CEPI), met to develop solutions. These health pros are working on a vaccine and other ways to stave off a potential epidemic that could spread person-to-person across the tropics and beyond.
"Twenty years have passed since its discovery, but the world is still not adequately equipped to tackle the global health threat posed by Nipah virus," said CEPI Chief Richard Hatchett in a press release. "This needs to change. Strengthening collaboration and knowledge sharing between Nipah virus experts, industry and key public-health stakeholders is crucial to the development of novel interventions against Nipah."
Fruit bats indigenous throughout equatorial regions and domesticated hogs are the main carriers of the disease, some outbreaks of which have killed as many as 40% to 75% of the people who contracted it, according to Charles Patrick Davis, an MD, PhD, a medical author for MedicineNet. Once a person contracts Nipah, also known as "NiV," they can also pass it on to others through person-to-person contact and contaminated food.
"Outbreaks of Nipah virus have so far been confined to South and Southeast Asia, but the virus has serious epidemic potential, because Pteropus fruit bats that carry the virus are found throughout the tropics and sub-tropics, which are home to more than two billion people," Hatchett said. "Nipah virus can also be transmitted from person to person, so in theory it could spread into densely populated temperate areas too."
Why Is There No Vaccine for Nipah (NiV)?
No health agencies around the world have approved any vaccines for Nipah, but that doesn't mean the medical research community has ignored the mortal threat. A similar microbe called the Hendra virus has up to 90 percent of the same proteins Nipah does, according to Frontiers in Veterinary Medicine. As a result, scientists have used the Hendra vaccine (currently approved for use on horses in Australia) to successfully vaccinate experimental animals against Nipah virus.
But the same vaccine doesn't work on pigs, one of the most dangerous transmission points because of the close contact between hogs and humans on pig farms. The first 1998-9 outbreak started among Malaysian pig farmers, killing 105 and nearly leading to the collapse of the nation's billion-dollar pork industry, according to the Malaysian Journal of Pathology.
Researchers are continuing to tweak the Hendra vaccine to try to find a form that works on pigs and/or humans.
"Despite these encouraging results and the continued threat posed by NiV, no vaccine candidate has progressed toward market for either pigs or humans," Frontiers states.
Other research teams have been testing treatments, namely remdesivir, which has shown some effectiveness in treating the deadly African Ebola virus. They published a May study in Science Translational Medicine that showed remdesivir treatment protected test animals from death after contracting the Nipah virus, but there were no human trials for remdesivir scheduled at the time that article published.
What Happens When You Get Nipah (NiV)?
The risk factors for this infection include having close contact with infected animals such as pigs, bats, and/or humans infected with the virus. In addition, consumption of raw date palm sap – a popular drink in parts of the tropics – is a significant risk factor since bat excrement often contaminates this substance, according to Dr. Davis.
A combination of tests diagnose NiV. Viral isolation, RT-PCR, and antibody detection by the ELISA tests are the tests that health care professionals use most often to diagnose Nipah virus infection, Dr. Davis said.
The signs and symptoms of NiV infection begin with:
- fever and headache,
- myalgia (muscle aches),
- sore throat,
- dizziness and/or,
- acute respiratory syndrome or atypical pneumonia.
Encephalitis (brain inflammation) follows, and those infected may exhibit drowsiness, disorientation, mental confusion, altered consciousness, and seizures. These symptoms may progress within 24-48 hours to coma and eventually death.
Supportive care – i.e. intravenous fluids, pain medication and other symptom treatment – is now the only available treatment for NiV, Dr. Davis said.