Hong Kong adjoins central Guangdong, and most imported live poultry in Hong Kong is from central Guangdong (Zhuhai and Shenzhen).
Therefore, Hong Kong and central Guangdong were considered as a single spatial unit.
Avian influenza A(H7N9) infection in humans, Guangdong, China, 2013–2015.
A) Geographic distribution of H7N9 in humans during the second (June 2013–May 2014) and third (June 2014–May 2015) waves. We used a Bayesian discrete phylogeographic approach to investigate spatial dynamics among 9 geographic regions.
However, whether these viruses persist locally across epidemic waves despite current interventions has yet to be answered.