Raw Sap Consumption Habits and Its Association with Knowledge of Nipah Virus in Two Endemic Districts in Bangladesh.

Nazmun Nahar,Shariful Amin Sumon,Mohammad Asaduzzaman,Fernando Garcia,Jaynal Abedin,Emily S Gurley,Stephen P Luby,Kajal Chandra Banik,Mahmudur Rahman,Nadia Ali Rimi,Repon C Paul,Rebeca Sultana,Vincent Jacobus Munster

doi:10.1371/journal.pone.0142292

Abstract

Human Nipah virus (NiV) infection in Bangladesh is a fatal disease that can be transmitted from bats to humans who drink contaminated raw date palm sap collected overnight during the cold season. Our study aimed to understand date palm sap consumption habits of rural residents and factors associated with consumption. In November-December 2012 the field team interviewed adult respondents from randomly selected villages from Rajbari and Kushtia Districts in Bangladesh. We calculated the proportion of people who consumed raw sap and had heard about a disease from raw sap consumption. We assessed the factors associated with raw sap consumption by calculating prevalence ratios (PR) adjusted for village level clustering effects. Among the 1,777 respondents interviewed, half (50%) reported drinking raw sap during the previous sap collection season and 37% consumed raw sap at least once per month. Few respondents (5%) heard about NiV. Thirty-seven percent of respondents reported hearing about a disease transmitted through raw sap consumption, inclusive of a 10% who related it with milder illness like diarrhea, vomiting or indigestion rather than NiV. Respondents who harvested date palm trees in their household were more likely to drink sap than those who did not own date palm trees (79% vs. 65% PR 1.2, 95% CI 1.1–1.3, p<0.001). When sap was available, respondents who heard about a disease from raw sap consumption were just as likely to drink it as those who did not hear about a disease (69% vs. 67%, PR 1.0, 95% CI 0.9–1.1, p = 0.512). Respondents’ knowledge of NiV was low. They might not have properly understood the risk of NiV, and were likely to drink sap when it was available. Implementing strategies to increase awareness about the risks of NiV and protect sap from bats might reduce the risk of NiV transmission.

Highlights

Nipah virus (NiV) infection is an emerging zoonosis that causes severe disease in both animals and humans
Half of the respondents reported drinking it during the last sap collection season putting them at risk of contracting NiV
Gender Women Men District Rajbari Kushtia Education

Summary

Introduction

Nipah virus (NiV) infection is an emerging zoonosis that causes severe disease in both animals and humans. Multiple lines of evidence support a causal relationship between raw date palm sap consumption and human infection with Nipah virus. Infrared photography demonstrates Pteropus bats in Bangladesh frequently directly contaminate raw date palm sap with their saliva [6, 7]. Laboratory studies demonstrate that Nipah virus survives for several days in date palm sap [8]. Laboratory animals exposed to date palm sap spiked with Nipah virus develop Nipah infection [8]. Several outbreak investigations in Bangladesh have found that people with Nipah virus infection are more likely to have drunk raw date palm sap than controls [7, 9,10,11]. Person-to-person transmission of human NiV has been identified [12,13,14], a finding that has broader public health implications including the risk of a pandemic [15]

Methods

Results

Conclusion