a randomized controlled trial of interventions to impede date palm sap contamination by bats to prevent nipah virus transmission in bangladesh随机对照试验的干预阻碍椰枣汁污染预防尼帕病毒传播蝙蝠在孟加拉国.pdfVIP

A Randomized Controlled Trial of Interventions to Impede Date Palm Sap Contamination by Bats to Prevent Nipah Virus Transmission in Bangladesh 1 1 1 1 1 Salah Uddin Khan *, Emily S. Gurley , M. Jahangir Hossain , Nazmun Nahar , M. A. Yushuf Sharker , Stephen P. Luby1,2 1 International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B), Dhaka, Bangladesh, 2 Centers for Disease Control and Prevention (CDC), Atlanta, Georgia, United States of America Abstract Background: Drinking raw date palm sap is a risk factor for human Nipah virus (NiV) infection. Fruit bats, the natural reservoir of NiV, commonly contaminate raw sap with saliva by licking date palm’s sap producing surface. We evaluated four types of physical barriers that may prevent bats from contacting sap. Methods: During 2009, we used a crossover design and randomly selected 20 date palm sap producing trees and observed each tree for 2 nights: one night with a bamboo skirt intervention applied and one night without the intervention. During 2010, we selected 120 trees and randomly assigned four types of interventions to 15 trees each: bamboo, dhoincha (local plant), jute stick and polythene skirts covering the shaved part, sap stream, tap and collection pot. We enrolled the remaining 60 trees as controls. We used motion sensor activated infrared cameras to examine bat contact with sap. Results: During 2009 bats contacted date palm sap in 85% of observation nights when no intervention was used compared with 35% of nights when the intervention was used [p,0.001]. Bats were able to contact the sap when the skirt did not entirely cover the sap producing surface. Therefore, in 2010 we requested the sap harvesters to use larger skirts. Durin