Pneumocystis carinii is not a major cause of pneumonia in HIV infected patients in Lusaka, Zambia.

The clinical occurrence of Pneumocystis carinii and Mycobacterium tuberculosis was investigated in patients infected with human immunodeficiency virus (HIV) who had clinical pneumonia of unknown aetiology in Lusaka, Zambia. The results were compared with a similar group of patients in Stockholm, Sweden. Induced sputum samples were stained for Pneumocystis by indirect immunofluorescence using monoclonal antibody 3F6 and toluidine blue O. Mycobacterial culture and acid fast stain were performed on the specimens from Lusaka. P. carinii cysts were detected in none of 27 Lusaka patients, compared to 10 of 33 Stockholm patients. M. tuberculosis was identified in 11 of 22 Lusaka patients tested. In conclusion, P. carinii could not be incriminated as the aetiological agent of HIV-associated pneumonia in Zambia in contrast to the situation in Sweden, where Pneumocystis is the dominating aetiological agent.