Impact of human immunodeficiency virus infection on the etiology and outcome of severe pneumonia in Malawian children.

BACKGROUND: HIV infection is a major risk factor for death in childhood pneumonia in HIV-endemic regions. Improved case management and preventive strategies require better understanding of the impact of HIV on causes, clinical presentation, and outcome.
METHODS: A prospective, clinical descriptive study of Malawian infants and children with severe pneumonia included blood culture and nasopharyngeal aspiration for diagnosis of pneumocystis pneumonia (PcP). A select group with consolidation on chest radiograph, and without severe hypoxia or hyperinflation, also had lung aspirate taken for culture and identification of bacterial deoxyribonucleic acid by real-time polymerase chain reaction (PCR).
RESULTS: There were 327 study patients with a median age of 11 months (range, 2 months-14 years). HIV prevalence was 51%. There were 58 cases of confirmed bacterial pneumonia, of which the most common bacterial isolates were Streptococcus pneumoniae and Salmonella typhimurium. Of the 54 lung aspirates, only 2 were positive on culture but 27 were positive for bacterial deoxyribonucleic acid by PCR. PcP was confirmed in 16 patients, and was associated with young age, severe hypoxia, HIV infection, and a very poor outcome. The overall case-fatality rate was 10% despite presumptive therapy for PcP and routine broad-spectrum antibiotic treatment appropriate for local antimicrobial susceptibility data. Most of the deaths occurred in infants of 2 to 6 months of age and PcP was associated with 57% of these deaths.
CONCLUSIONS: PcP is a major barrier in reducing the case-fatality rate of severe pneumonia in infants of HIV-endemic communities. The use of PCR on lung aspirate specimens greatly increased the diagnostic yield.