Primary meningococcal conjunctivitis: report of 21 patients and review.

Neisseria meningitidis is an uncommon cause of acute bacterial conjunctivitis. Twenty-one cases of primary meningococcal conjunctivitis (PMC) are reported herein and 63 cases published in the literature since 1899 are reviewed. In the 84 cases of PMC available for analysis, the male-to-female ratio was 1.76:1; nine of the patients were neonates, 55 were children, and 20 were adults. Conjunctivitis was unilateral in 66.3% of the patients. Gram stain of conjunctival exudate disclosed gram-negative diplococci in all cases in which it was done. Culture of the conjunctival exudate yielded N. meningitidis in all cases, and 44% of the isolated meningococci belonged to serogroup B. Ocular complications, which occurred in 15.5% of the patients, most frequently were corneal ulcers. Systemic meningococcal disease developed in 17.8% of the patients; the overall mortality was 13.3% for patients with PMC complicated by systemic disease. Development of systemic disease was significantly more frequent in patients receiving only topical therapy than in those treated with systemic therapy (31.71% vs. 2.38%; P = .001). Gram-negative diplococci observed in conjunctival exudate are an indication for systemic antibiotic therapy because of the risk of systemic complications associated with the use of topical therapy alone. When properly treated, patients with PMC have a favorable prognosis.