A fungal pneumonia caused by Pneumocystis jiroveci and seen almost exclusively as an opportunistic infection in immunosuppressed patients. It is one of the AIDS-defining diseases in HIV infection, but can also occur in other forms of immunosuppresion, e.g. chemotherapy. It was formerly known as Pneumocystis carinii pneumomonia, but since renaming of the caustive organism, the abbreviation has been adapted to mean Pneumocystis jiroveci(/carinii) pneumonia. Treatable with co-trimoxazole.
A chest radiograph may show bilateral, diffuse infiltrates.
Induced sputum (via nebulised hypertonic saline) or a broncho-alveolar lavage specimens should be sent for microbiological confirmation. This may involve:
- Immunofluorescence (fluorescent labelled antibodies against organism)
- Cytological/histological staining - may be less sensitive in non-HIV cases as the organism count is often lower; PCR may be better.