An outbreak of Pneumocystis carinii pneumonia in homosexual men.

Pneumocystis carinii pneumonia has rarely been reported in previously healthy persons over the age of 6 months. Five cases of P. carinii pneumonia in adult homosexual men, confirmed by biopsy results, are reported. All five patients were seropositive when tested for antibodies to cytomegalovirus and four had evidence of active concurrent cytomegalovirus infections. Kaposi's sarcoma was shown in two of the patients and one had possible Pneumocystis infection of the central nervous system as well as P. carinii pneumonia. Three patients had second episodes of Pneumocystis pneumonia. Four of the five patients have died. Past or concurrent cytomegalovirus infection and homosexuality were the only common epidemiologic features in all five patients.