Understanding Pig and Poultry Trade Networks and Farming Practices Within the Pacific Islands as a Basis for Surveillance.

Pacific Island countries have large pig and poultry populations. Yet little is known about patterns of contact between animals and how this influences disease spread in these islands. The objectives of this study were to examine farmer practices and the movements of pig and poultry within the Pacific Islands using questionnaires and social network analysis (SNA) tools to understand disease spread in the region. Questionnaire-based surveys were conducted in Fiji, Papua New Guinea (PNG), Solomon Islands and Vanuatu with interviews of 310 pig farmers and 491 poultry farmers. Pacific Island farmers were found to have few animals (median = 7 pigs/farm, IQR 4-12), (median = 50 chicken/farm, IQR 23-52), (median = 10 ducks/farm, IQR 4-25), (median = 12 Muscovy ducks/farm, IQR 7-28) and a diversified number of species. A large proportion of farmers (44.6-61.3%) do not implement any preventive or control measures, yet the majority (80.6-88%) did not experience any animal diseases over the past 12 months. Most farmers never ask for veterinary care, never engage in laboratory testing and do not report when their animals show clinical signs. Many pig farmers (31.8%) trade within their communities only and sell (24.5%) directly to consumers which reduces the risk of diseases spreading. Our results show an association between farmers that report having had disease on their farm in the past 12 months and movements of animals on and off their farms. The capitals of the studied provinces in PNG, Vanuatu and Solomon Islands were identified as the most connected nodes of both pig and poultry trade, while Fiji networks appeared much less connected. Our study found that farmer practices increased the risk of disease spread, but this was currently limited by trading practices. The SNA results serve as a basis for more targeted disease surveillance and better use of available resources for disease prevention and control.