To the Editor.—
The article by Rao et al reporting "Pneumocystis carinii Pneumonia: Occurrence in a Healthy American Infant" was extremely interesting, considering the scarcity of similar reports and the current belief by most workers in the field that Pneumocystis occurs symptomatically only in the immunosuppressed.Since physicians may be led by this report to treat blindly with trimethoprim in occult pneumonias of infancy, I think it is proper to raise some questions: How many parasites were seen? Were photographs taken? Was a control section of known positive Pneumocystis infection stained at the same time? Were precipitin antibodies to Pneumocystis demonstrated? Was pneumocystis antigenemia confirmed in this child?Having this information would certainly influence my evaluation of this reported case and others that I might see in the future.