Search for extrapulmonary Pneumocystis carinii in an animal model

Pneumocystis carinii-infected immunosuppressed ferrets and rats were searched for P. carinii cysts and trophozoites in extrapulmonary organs, including the heart, liver, stomach, kidney, and spleen. Foci of P. carinii were found in the liver or kidney of 4 (10%) of 40 ferrets but in no extrapulmonary sites of 30 rats with P. carinii pneumonitis. Attempts to identify P. carinii from immunosuppressed rat or ferret blood or propagate the organism intraorbitally in immunosuppressed rats were unsuccessful. Pneumocystis carinii was identified from aspirated stomach contents of ferrets but in none of the rats infected with P. carinii pneumonitis.