A case of Haemophilus parainfluenzae pneumonia

A 41 year old woman presented with community acquired pneumonia (CAP) which failed to resolve following treatment with amoxycillin and cefaclor prior to referral. Quantitative culture of sputum revealed a pure growth. of Haem ophilus parainfluenzae and, following antibiotic susceptibility testing of the isolate, ciprofloxacin was prescribed resulting in resolution of the in fection. Immunological investigations showed that the patient had a high ti tre of H parainfluenzae specific IgM. The combination of a pure growth of H parainfluenzae, a response to appropriate antimicrobial therapy, and the p resence of a specific antibody response indicated that this organism had a pathogenic role in the patient's pneumonia and should be considered in the differential diagnosis of CAP.