According to Chen Hour-young, director of the division of viral diseases at the CDC, the ever-increasing volume of international travel means that infectious diseases can spread without regard for borders. Also, rapid population growth and urbanization help multiply the possibilities for transmission of pathogens, while over-development and deforestation are changing the habitats of disease-bearing insects.
衛生署疾病管制局新興傳染病召集人陳豪勇指出，交通日益頻繁，使得傳染病無國界；全球人口激增、鄉村都市化，加速病原散佈；過度開發、伐林，改變了病原蟲媒的棲息地。