BOZEMAN – Though Nipah virus was first identified in 1999, its 2018 appearance in Kerala, an Indian state on the Arabian Sea near the tip of the subcontinent, was a surprise that prompted action for researchers at Montana State University.
“We can’t predict why or where it’s going to emerge next,” said Raina Plowright, an assistant professor in the Department of Microbiology and Immunology in the College of Letters and Science and the College of Agriculture.
After the 2018 outbreak, which killed 21 people in Kerala, Plowright and members of her laboratory began working with biologists in the region to formulate a scientific response, focused on curbing potential outbreaks by identifying their source.
Plowright leads the Bozeman Disease Ecology Lab, which studies the dynamics of zoonotic pathogens in wildlife reservoir hosts and how a pathogen such as a virus or disease-causing bacteria spreads from animals to humans, also called “spillover.” Her research often focuses on bats, the natural host for Nipah virus.
“MSU is a wonderful place to research tropical bats,” Plowright said. “It’s a great community of scientists at a very high standard. We are also close to Rocky Mountain Labs in Hamilton, Montana, where our collaborators have the facilities to process our samples at high containment.”
Plowright was co-lead author of “Prioritizing surveillance of Nipah virus in India,” a paper published at the end of June in the Public Library of Science journal Neglected Tropical Diseases. The paper sought to identify which of the more than 100 bat species in India may act as reservoirs for the virus.
Prior to the study, only one species of fruit bat in India was a known host for Nipah virus. In the paper, Plowright and her team identified at least 11 species in the country that had evidence of henipavirus — or exposure to it — and an additional four species as potential carriers.
To make the predictions, Plowright’s group collated available data about the genus henipavirus, which includes Nipah virus. Data, however, was scarce. Plowright said she only found three studies of Nipah virus in bats in India, each looking at a single point in time with no follow-through. Where information was available, samples from bats were mostly taken outside of India, hindering any possibility of localizing results.
Each step showed a lack of scientific data that underscored the need for further study. The paper, according to Plowright, is a critical step toward greater understanding of the region’s bat species and their role in spillover of Nipah virus.
“We outlined a path forward,” Plowright said.
Nipah virus can be transmitted from animals to humans through bodily fluids. For example, if a bat’s saliva or urine contaminates fruit which someone then eats, the person may be infected. In Bangladesh, Nipah virus outbreaks occur almost annually during the date palm sap collection season. This virus can also spread through an intermediate host, such as pigs that have eaten contaminated fruit and which are, in turn, eaten by humans. Once a human is infected, the virus can spread to other humans.
Symptoms of Nipah virus include severe respiratory infection and inflammation in the brain known as encephalitis, which can be fatal. There is no known treatment or vaccine, and fatality rates are estimated between 40% and 75%, according to the World Health Organization. Because so little is known about Nipah and its epidemic potential, the WHO named it a priority disease for accelerated research and development in 2018.
“Henipaviruses such as Nipah virus warrant attention from the global health community because of their ability to spread from person to person, although our understanding of which strains are most transmissible among humans, and why, is poor,” the paper states.
Nipah virus appeared again in Kerala in June. The outbreak was contained, and the Indian Council of Medical Research’s National Institute of Virology declared the region safe last week. But the worry remains, again highlighting the need for further research.
“Every time one of these pathogens spills over from animals to humans it’s a roll of the dice,” Plowright said.
Reader Comments(0)