avenue of infection

例句：

1. 1. The outbreak wastraced back to a single source ofcontamination.
   这次疫情是由一个单一污染源引起的。
2. 2. The hospital is the mainavenue of infection for patients with infectiousdiseases.
   医院是患有传染病的患者的主要感染途径。
3. 3. The research team identified several potential avenues of infection that could be controlled.
   研究团队识别了几个可能被控制的感染途径。