The Nipah virus poses a potential risk of spilling over from bats to humans across South and Southeast Asia, a study suggests. The Nipah virus causes near-annual outbreaks in South Asia, with a mortality rate above 70%. Pteropus bats are the main reservoir host of the virus, but the spatial and temporal dynamics of viral transmission in bats are unclear. Jonathan Epstein and colleagues conducted a six-year study to assess viral genetic diversity and bat ecology and immunology. The authors caught and examined 2,789 Pteropus medius bats in Bangladesh between 2006 and 2012. Viral transmission occurred throughout the country and throughout the year. Modeling revealed that local transmission was affected by the density of bat populations and by waning immunity through population turnover and through antibodies that are lost over time in individual bats. Nipah virus RNA was detected in bats located inside and outside the Nipah Belt, a region where human outbreaks primarily occur seasonally in conjunction with the consumption of date palm sap contaminated with bat excrement. The findings suggest a potential risk for human spillover across the range of Pteropus bats and potentially explain outbreaks that are not tied to the seasonal and regional consumption of date palm sap, according to the authors.
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Article #20-00429:
"Nipah virus dynamics in bats and implications for spillover to humans," by Jonathan Epstein et al.
MEDIA CONTACT:
Jonathan Epstein
EcoHealth Alliance
New York, NY
e-mail: epstein@ecohealthalliance.org