传染 (chuán rǎn): 感染する

He caught a bad cold and coughed severely, and as a result, the whole family was infected by him.

During flu season, doctors remind everyone to wash hands frequently and wear masks to prevent the virus from spreading among people.

This skin disease can be transmitted through direct contact, so patients should avoid sharing towels with others.

The doctor said he had an infectious disease and needed isolation treatment to prevent infecting other patients.