Abstract
In the face of an ever-increasing global high pathogenicity avian influenza (HPAI) problem vaccination is increasingly considered. HPAI is endemic in Bangladesh. Vaccination against HPAI in chickens was introduced in Bangladesh in 2012 to curb the increasing number of HPAI outbreaks. While leading to a dramatic decrease in the number of outbreaks, research in both live bird markets and poultry farms identified high incidences of HPAI infected, yet asymptomatic, poultry. At the same time, the number of outbreaks in wild birds in Bangladesh are seemingly on the increase.
To avoid silent spread, vaccination should stop replication of the pathogen and prevent infectiousness of infected hosts and not only reduce disease symptoms. Vaccination of farmed chickens in Bangladesh thus does not meet the ultimate objective of vaccination and bears the risk of promoting silent spread. Still, domestic ducks rather than chickens may well be the biggest player in causing the perpetuation of the HPAI problem in Bangladesh; Bayesian phylodynamic modelling revealed frequent bidirectional viral transitions between domestic ducks, chickens, and house crows, where domestic ducks are predominantly acting as the source. Taken together the here collated research results for Bangladesh suggest that implementation of vaccination should be accompanied with monitoring to avoid silent spread and that domestic ducks deserve particular attention to turn the tide in the battle against HPAI.
To avoid silent spread, vaccination should stop replication of the pathogen and prevent infectiousness of infected hosts and not only reduce disease symptoms. Vaccination of farmed chickens in Bangladesh thus does not meet the ultimate objective of vaccination and bears the risk of promoting silent spread. Still, domestic ducks rather than chickens may well be the biggest player in causing the perpetuation of the HPAI problem in Bangladesh; Bayesian phylodynamic modelling revealed frequent bidirectional viral transitions between domestic ducks, chickens, and house crows, where domestic ducks are predominantly acting as the source. Taken together the here collated research results for Bangladesh suggest that implementation of vaccination should be accompanied with monitoring to avoid silent spread and that domestic ducks deserve particular attention to turn the tide in the battle against HPAI.
Co-Author(s)
Marcel Klaassen (1)
Ariful Islam (1,2)
1 - School of Life and Environmental Sciences, Deakin University, Geelong, Victoria, Australia
2 - Gulbali Institute, Charles Sturt University, Wagga Wagga, NSW, Australia
Abstract Category
Diagnostics, vaccination, or other mitigation strategies for poultry and wildlife