Case definition and ethics statement.

Acute conjunctivitis was defined as any inflammation of the conjunctiva characterized by redness of the eye, and its symptoms may include pain, itching, and foreign body sensation, accompanied by tears or increased secretion (15). All participants who met the case definition were required to provide written informed consent for the use of their clinical information and samples for the study.

This study was approved by the second session of the Ethics Review Committee of the National Institute for Viral Disease Control and Prevention (IVDC) at the Chinese Center for Disease Control and Prevention (CDC). All methods in this study were performed according to the relevant guidelines and regulations.