In Thailand, TSs and HTs may therefore contribute to the rapid spread of avian influenza locally. In contrast with
previous studies (Poolkhet et al., 2012, 2013), we found that in Thailand, TTs range over a larger area and handle approximately 75 % of all backyard chickens collected, although they visit significantly fewer villages. Their activity may play an important role in the spread of avian influenza, as they provide sporadic medium distance jumps between villages. In summary, the present study highlights how the structure of backyard poultry trade networks in Thailand may contribute
to disease diffusion through combined expansion and relocation processes, which are facilitated by overlapping
trade zones.