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Partnerships for enhanced engagement in research (PEER) SCIENCE
Cycle 1 (2011 Deadline)

Defining the ecology of the Nipah virus outbreaks in Bangladesh: Identifying additional potential foodborne and livestock transmission routes   

PI: Muhammad Salah Uddin Khan, ICDDR
US Partner: Peter Daszak, EcoHealth Alliance Inc
Project dates: June 2012 - March 2016
Project Overview

A bat licking sap from the shaved part of a date palm tree (Photo courtesy Dr. Khan).

Two rats licking sap from the shaved part of a date palm tree( Photo courtesy Dr. Khan).

Nipah virus (NiV) is an emerging zoonotic virus (a virus transmitted to humans from animals) that causes high mortality in humans. In addition to human-to-human transmission, epidemiological studies have identified another possible transmission pathway, namely from fruit bats of the Pteropodidae family to humans when people drink contaminated date palm sap. Human NiV cases in Bangladesh have been found to be seasonal, coinciding with the date palm harvesting season (November to March), and consumption of date palm wine appears to serve as a major portal for infection due to contamination of palm sap from contact with urine or saliva from infected fruit bats. 
In addition to foodborne transmission pathways, animals other than bats may play a role in transmission. The project team has previously studied livestock during outbreak investigations, and as they expand their work under the current PEER grant they will pursue the hypothesis that multiple species of animals (including dogs, cats, cattle, goats, horses, and pigs) may acquire and spread Nipah infection during an outbreak. The Bangladeshi and U.S. researchers will develop sampling strategies and analytical approaches to assess the risk of infection via livestock and food-borne routes. In order to better understand the various possible routes of NiV transmission, this project will involve screening domestic, peri-domestic, and feral animals in a NiV outbreak to look for evidence of NiV infection. Furthermore, the researchers will look at bats’ date palm sap drinking behavior year round, in the locations where harvesters collect and ferment date palm sap for wine production. Beyond its research aspects, this project will also provide training in NiV surveillance, field sampling techniques, biosafety practices, and outbreak response for veterinarians under the Bangladeshi Department of Livestock Services, Ministry of Agriculture, and the Forestry Department.
Summary of Recent Activities
During January-March 2015, the research team has collected 21 nights of camera observation data documenting bats’ visits to date palm sap trees. 8993 bats’ visits were recorded  between January and  March of 2015, with the aaverage duration of each visit being 1.25 seconds. The research team has been analyzing 22 months of camera observation data of bats' feeding behavior and recorded a total of 26,870 bat visits (5% Pteropus, 90% non- Pteropus and 5% unidentified) from 616 observation tree-nights. Median duration of each visit was higher for Pteropus bats than non-Pteropus bats (8 versus 0.03 minutes, P< 0.001). Median duration of contact with date palm sap was higher for Pteropus bats (0.67 versus 0.03 minutes, P<0.001) for each visit.  The average number of Pteropus bat visits per night was the highest during spring/March-May (17) followed by winter (December-February), post monsoon (October-November), and monsoon (June-September). Outreach efforts have been ongoing as well. Dr. Khan, presented findings of his study during the talk entitled “Foodborne Pathways for Nipah Virus Transmission in Bangladesh” at the Environmental and Global health Departmental Seminar of University of Florida, on March 24, 2015, Gainesville, FL. Based on recent data analysis, an abstract has been prepared and submitted for presentation at the International Conference for Emerging Infectious Diseases to be held in Atlanta, GA from 24-26 August, 2015. The team is currently processing documents to ship the animal samples to Australian Animal Health Laboratory to test for Nipah and related virus antibodies. In order to complete sample collection and finalize analysis of the data, the duration of the project has been extended until March 2016.