Diagnosis of Pneumocystis carinii pneumonia from non-invasive sampling of respiratory secretions.
 An infant infected with HIV presented with fever, tachypnoea, hypoxia, and radiological evidence of bilateral pneumonitis.
 Fluorescent antibody technique identified Pneumocystis carinii within 24 hours from secretions obtained by nasopharyngeal aspiration.
 This rapid, non-invasive method should be the first line investigation of suspected P carinii pneumonia in immunocompromised patients.
