CDC

Nongroupable Neisseria meningitidis conjunctivitis outbreak hits Texas military trainees

September 9, 2025

Between February and May 2025, an outbreak of Neisseria meningitidis conjunctivitis occurred among 41 military trainees at Joint Base San Antonio-Lackland, Texas. All affected individuals were young, healthy, and immunocompetent, and had received the quadrivalent meningococcal vaccine upon arrival. The causative strain was unencapsulated (nongroupable) and identified via whole genome sequencing, which confirmed the cases were related.

Despite adherence to hygiene protocols and no identifiable source, the outbreak spread across 37 unique training groups. Most cases presented with unilateral mucopurulent discharge, often following an upper respiratory infection. One patient developed periorbital cellulitis, requiring IV antibiotics, but all others responded well to topical antibiotics (moxifloxacin, ciprofloxacin, or erythromycin) with rapid symptom resolution.

Key lessons for clinicians:

• N. meningitidis, though rare, should be considered in outbreaks of bacterial conjunctivitis in communal settings.
• Culture and genomic sequencing are critical for identifying etiology and guiding response.
• Topical antibiotics may be sufficient for treating nongroupable strains in healthy individuals.
• Vigilant surveillance and early intervention can prevent complications and limit spread.

Source:

Ching SJ, et al. (2025, September 4). CDC: Morbidity and Mortality Weekly Report. Outbreak of Neisseria meningitidis Conjunctivitis in Military Trainees — Texas, February–May 2025. https://www.cdc.gov/mmwr/volumes/74/wr/mm7433a1.htm