What is the leading cause of Ophthalmia neonatorum in the United States?

• A. Gonorrhea infections
• B. Chlamydia infections
• C. HSV infections
• D. Staphylococcus aureus infections

Answer: (B)

Ophthalmia neonatorum in the United States is most commonly caused by Chlamydia trachomatis. This neonatal conjunctivitis is acquired during passage through the birth canal, and in the U.S. widespread newborn prophylaxis has reduced gonococcal disease, leaving chlamydial infection as the more frequent cause. Chlamydial conjunctivitis typically appears later—about 5 to 14 days after birth—and presents with mucopurulent discharge and conjunctival injection that is milder than the hyperacute, purulent presentation seen with Neisseria gonorrhoeae. While gonococcal infection can cause a severe, rapidly progressing eye infection, its incidence has decreased with prophylaxis, making chlamydial infection the leading cause. HSV and Staphylococcus aureus are less common causes of ophthalmia neonatorum.