Primary meningococcal pneumonia in elderly patients.

Neisseria meningitidis infection in humans usually manifests as meningitis and septicemia with skin manifestations. Infections of the respiratory tract with N meningitidis have been documented in the past, but often this organism is not routinely considered in the differential diagnosis of pneumonia. The pathogenic role of N meningitidis in lower respiratory tract infections may be underestimated because its isolation is difficult, particularly when oropharyngeal flora are present. We profile 2 elderly patients with primary meningococcal pneumonia to show the importance of Gram stain and culture in early diagnosis. These modalities helped guide treatment and prophylactic measures.