Active surveillance of avian influenza virus in poultry in backyard farms, small-scale farms, and observation sites before exporting poultry for sale, and poultry carcasses in fresh markets in four border provinces of Thailand

Abstract

Avian influenza outbreaks are still sporadic in neighboring countries. The central and local livestock and health sectors collaborated to create an active surveillance of avian influenza and a communication channel for exchanging avian influenza information obtained from the active surveillance. In addition, both sectors set guidelines for jointly investigating a disease if an avian influenza virus was reported in the border districts of Thailand adjacent to the Lao People’s Democratic Republic (Lao PDR). The surveillance areas were chosen in the six districts of four border provinces and the active surveillance was conducted from March 2018 to August 2021. The target populations for the active surveillance included (1) backyard poultry or small poultry farms, (2) poultry at observation sites before exporting poultry for sale at the border markets, and (3) poultry carcasses sold at fresh markets. Local livestock officers collected poultry samples every month. Five specimens/swabs were pooled in a tube containing viral transport media. Oropharyngeal swabs were collected from poultry at farms or backyards in six districts (approximate 360 specimens per month), and the observation sites before exporting poultry in two districts (approximate 30 specimens per month). Trachea specimens were collected from the fresh markets in six (approximate 60 specimens per month). All specimens were sent to the laboratories of the Department of Livestock Development and the Monitoring and Surveillance Center for Zoonotic Diseases in Wildlife and Exotic Animals laboratory, Faculty of Veterinary Science, Mahidol University for Avian Influenza diagnosis by chorioallantoic sac inoculation of embryonated chicken eggs and Real-time RTPCR. A total of 18,370 specimens collected from native chickens and ducks raised in backyards or on small-scale farms was negative to highly pathogenic avian influenza (HPAI) virus. Active longitudinal surveillance of poultry population in collaboration of public health and animal health sectors should be rigorously maintained to ensure the early detection of avian influenza virus, timely information sharing, and rapid and effective disease control and prevention.