Satellite telemetry tracks flyways of Asian Openbill storks in relation to H5N1 avian influenza spread and ecological change

Parntep Ratanakorn,Anuwat Wiratsudakul,Kridsada Chaichoune,Ladawan Sariya,Krairat Eiamampai,Witthawat Wiriyarat,Pilaipan Puthavathana,Sarin Suwanpakdee

doi:10.1186/s12917-018-1683-x

Abstract

BackgroundAsian Openbills, Anastomus oscitans, have long been known to migrate from South to Southeast Asia for breeding and nesting. In Thailand, the first outbreak of H5N1 highly pathogenic avian influenza (HPAI) infection in the Openbills coincided with the outbreak in the poultry. Therefore, the flyways of Asian Openbills was determined to study their role in the spread of H5N1 HPAI virus to poultry and wild birds, and also within their flocks.ResultsFlyways of 5 Openbills from 3 colonies were monitored using Argos satellite transmitters with positioning by Google Earth Programme between 2007 and 2013. None of the Openbills tagged with satellite telemeters moved outside of Thailand. Their home ranges or movement areas varied from 1.6 to 23,608 km2 per month (95% utility distribution). There was no positive result of the viral infection from oral and cloacal swabs of the Openbills and wild birds living in the vicinity by viral isolation and genome detection during 2007 to 2010 whereas the specific antibody was not detected on both Openbills and wild birds by using microneutralization assay after 2008. The movement of these Openbills did not correlate with H5N1 HPAI outbreaks in domestic poultry but correlated with rice crop rotation and populations of the apple snails which are their preferred food. Viral spread within the flocks of Openbills was not detected.ConclusionsThis study showed that Openbills played no role in the spread of H5N1 HPAI virus, which was probably due to the very low prevalence of the virus during the monitoring period. This study revealed the ecological factors that control the life cycle of Asian Openbills.

Highlights

Asian Openbills, Anastomus oscitans, have long been known to migrate from South to Southeast Asia for breeding and nesting
Satellite telemetry had been conducted to monitor the flyways of 5 Asian Openbills in correlation to their potential role on H5N1 avian influenza (AI) spread to poultry and domestic birds and within their flocks
The flyway analysis showed that Openbills played no role in AI spread which was probably due to the low prevalence of H5N1 virus during the monitoring period of 6 years

Summary

Introduction

Asian Openbills, Anastomus oscitans, have long been known to migrate from South to Southeast Asia for breeding and nesting. In Thailand, the first outbreak of H5N1 highly pathogenic avian influenza (HPAI) infection in the Openbills coincided with the outbreak in the poultry. The flyways of Asian Openbills was determined to study their role in the spread of H5N1 HPAI virus to poultry and wild birds, and within their flocks. Asian Openbills or Asian Open-billed storks, Anastomus oscitans, are large wading birds in the family Ciconiidae [1]. The birds get their name from the natural open space between the curved inner surfaces of the mandibles in adults [2]. The outbreaks of H5N1 highly pathogenic avian influenza (HPAI), occurred in Thailand in January 2004 and resulted in enormous economic losses of poultry and several human deaths. The prevalence decreased to 0.91% (95% CI: 0.1–1.7) in 2005, and 0% in 2006 and 2007 [11]

Methods

Results

Discussion

Conclusion