Social network analysis for poultry HPAI transmission

Abstract

In this survey study, the networks among poultry farms and related poultry enterprises in two counties in China (Feixi County in Anhui Province and Beizhen city in Liaoning Province) were analysed and evaluated focusing on the connectivity of contacts, movements, and potential pathogen transmission. The Feixi County poultry production network exhibited greater connectivity, which incorporated approximately 94% of the farms interviewed in a major component (a set of connected farms not linked with each other), mainly due to linkages of backyard farms through local produce stores and individual agents, whilst the Beizhen City network was more fragmented owing to independent in-house operations (from breed, raise, to slaughter and process) of a few large companies, with multiple smaller components. A range of factors influencing the contacts/movements among farms (act as bridges) were identified in this study. Ability to predict the pathway with the network characteristics on the basis of the factors, such as entity type and geographic location, is useful for developing risk-based approaches for disease prevention, surveillance, early detection, and effective controlling.

Dynamics of inter-farm transmission of highly pathogenic avian influenza H5N6 integrating vehicle movements and phylogenetic information

“…Recently, many studies have identified the role of animal movement in transmitting a pathogen between livestock farms using network analysis. Previous network studies have identified a relationship between contact properties of poultry farms and HPAI occurrence by comparing network metrics; for example infected premises were more likely to have a higher degree of centrality and betweenness centrality 3 , 4 . More recently, one study introduced a permutation approach to evaluate the intermediary role of a particular link or node in the contact network on the spread of pathogen on a community level 5 .…”

Knowledge and remaining gaps on the role of animal and human movements in the poultry production and trade networks in the global spread of avian influenza viruses – A scoping review

“…In terms of human movements, the most studied populations were poultry companies' technicians and/ or workers, veterinarians and traders. Some references also considered vaccination and cleaning and disinfection teams [49] or private individual technicians [70].…”

“…International trade of live birds day-old chicks [28,29] hatching eggs [28] chickens [30,31] ducks, turkeys [31] Illegal trade of live birds spent hens, ducklings, day-old chicks [27] National movements day old duckling, hatching eggs duck [72,73] ostrich chicks [72] Movements to poultry show chicken, duck [72] Fomite movements Slaughterhouses vehicles ducks [41] poultry [42,50,51,71] broiler chickens [47,70,74] layers [47,74] Catching team or bird pick up poultry [42,48,71] broiler chickens [46,47,55,56,74] layers [46,47,55,56,74] turkeys and broiler ducks [46] ready to lay parents and parents and grandparents stock [46] Feed deliveries poultry [50,52,71] broiler chickens [43,49,54,65,68,70,73,…”

“…Shared equipment free-range layers [56] broiler chickens [56,70] Human movements Traders poultry [32,33,67] Veterinarian poultry [52] broiler chickens [65] layers [65] ready to lay parents and parents and grandparents stock [46] Vaccination team broiler chickens, layers, turkeys, quails and breeders [49] Cleaning and disinfection team broiler chickens, layers, turkeys, quails and breeders [49] Individual technician broiler chickens [70] Technician/ company workers ducks [41,72] poultry [42,50] broiler chickens [43,49,54,55,72] turkeys, quails and breeders [49] layers [49,55,56,72] Shared farm workers (part-time, hired help) broiler [43,54,56] layers [56] Non-company commercial services (gas delivery, meter reading, maintenance)…”

Cattle Manure Trade Network Analysis and the Relevant Spatial Pathways in an Endemic Area of Foot and Mouth Disease in Northern Thailand

“…Social network analysis (SNA) has been applied as an important methodological approach of veterinary epidemiology to document contact patterns among interacting individuals and to characterize animal movement as it relates to the spread of disease [20][21][22]. Studies using SNA have shown that farmers, cattle tradesmen, and animal markets were key players in the spread of FMD among farm animals, and particular attention should be paid to these important nodes when attempting to reduce future FMD outbreaks [23][24][25].…”