Importance: Acute infectious conjunctivitis is a common ocular condition with major public health consequences.
Objective: To assess regional variations and microbial etiologies of acute infectious conjunctivitis to guide treatment.
Design, Setting, And Participants: In this cross-sectional study, patients with presumed acute infectious conjunctivitis were enrolled in the study at 5 sites (Honolulu, Hawaii; Los Angeles, San Francisco, and San Diego, California; and Petah-Tikva, Israel) from March 2021 to March 2023.