Pneumocystis carinii isolated from lung lavage fluid in an infant with cystic fibrosis.

Pneumocystis carinii (P. carinii) cysts were identified in bronchoalveolar lavage fluid from a 15-week-old child newly diagnosed with cystic fibrosis who presented with bronchitis, pneumonia, and weight loss. The child was not infected with human immunodeficiency virus (HIV), and there was no evidence of impaired immunity or exposure to individuals with known or suspected P. carinii disease. Culture of the lavage fluid also revealed pathogens typical of lung disease associated with cystic fibrosis. It is suspected that the presence of P. carinii in this patient represented a new acquisition, as has been described in immunocompetent infants and children. Whether P. carinii infection complicated cystic fibrosis-associated lung disease in this patient is unknown.