The high burden of Pneumocystis carinii pneumonia in African HIV-1-infected children hospitalized for severe pneumonia.

OBJECTIVE: To evaluate the burden of Pneumocystis carinii pneumonia (PCP) and the usefulness of induced sputum and nasopharyngeal aspirates (NPA) in diagnosing PCP in African children in whom the use of bronchoalveolar lavage is unavailable.
DESIGN: Children aged 2-24 months who were either known or suspected of being HIV-1 infected and who were hospitalized for severe pneumonia were investigated for P. carinii using induced sputum and NPA. P. carinii identification was performed using a direct monoclonal antibody immunofluorescent stain. A group of children who subsequently died also had lung biopsies performed.
RESULTS: P. carinii cysts were identified in 51 out of 105 (48.6%) children either from induced sputum (37/105, 35.2%) or NPA (26/101, 25.7%) samples, or from both. Neither clinical nor laboratory tests were useful in distinguishing between HIV-1-infected children with and without PCP. Twenty-eight per cent (14/51) of HIV-1-infected children who developed PCP had a history of being on cotrimoxazole prophylaxis at the time of their illness. Mortality rates of HIV-1-infected children with and without PCP were equally high (27.5 and 27.8%, respectively). Histological evidence of PCP and cytomegalovirus pneumonia was observed on post-mortem lung biopsy in eight out of 18 (44.4%) children each. Using post-mortem lung histology as a reference, the sensitivity and specificity for induced sputum and NPA in diagnosing PCP were 75 and 80%, respectively.
CONCLUSION: Strategies to reduce the high burden of PCP, which can successfully be diagnosed using NPA and induced sputum, in HIV-1-infected children hospitalized with severe pneumonia are urgently warranted in Africa.