A 6-day-old infant presents with bilateral mucopurulent eye discharge. Which historical finding best explains the etiology?

A 6-day-old infant presents with bilateral mucopurulent eye discharge. Which historical finding best explains the etiology?

• A. Infant is hepatitis B positive
• B. Infant received silver nitrate drops
• C. Mother has chlamydia
• D. Delivery was by C-section

Answer: (C)

Neonatal conjunctivitis presents with timing and discharge type that point to the organism acquired during birth. When a newborn shows mucopurulent discharge starting about a week after birth, the most likely cause is Chlamydia trachomatis transmitted from an infected mother during vaginal delivery. This pattern fits the typical 5–14 days after birth onset and the milder, mucopurulent drainage rather than the very copious purulent discharge seen with gonococcal infection, which tends to present earlier (within 24–48 hours). Other details fit less well: hepatitis B status has no bearing on neonatal eye infection; silver nitrate drops were historically used to prevent gonococcal conjunctivitis but describe a prophylactic measure, not the causative scenario; delivery by C-section reduces exposure to birth canal pathogens and would make this infection less likely, not explain it. Thus, maternal chlamydial infection best explains the infant’s presentation.

Neonatal conjunctivitis presents with timing and discharge type that point to the organism acquired during birth. When a newborn shows mucopurulent discharge starting about a week after birth, the most likely cause is Chlamydia trachomatis transmitted from an infected mother during vaginal delivery. This pattern fits the typical 5–14 days after birth onset and the milder, mucopurulent drainage rather than the very copious purulent discharge seen with gonococcal infection, which tends to present earlier (within 24–48 hours).

Other details fit less well: hepatitis B status has no bearing on neonatal eye infection; silver nitrate drops were historically used to prevent gonococcal conjunctivitis but describe a prophylactic measure, not the causative scenario; delivery by C-section reduces exposure to birth canal pathogens and would make this infection less likely, not explain it. Thus, maternal chlamydial infection best explains the infant’s presentation.