Bacterial pneumonia in HIV-infected patients:: use of the pneumonia severity index and impact of current management on incidence, aetiology and outcome

Objectives Despite a recent decrease, bacterial pneumonia (BP) is still the most common admission diagnosis in HIV patients. We analyse BP incidence, characteristics and prevention measures. Methods Observational study of all patients hospitalized for BP in a tertiary hospital in Barcelona, Spain, from January 2000 to December 2005. Demographic and HIV-related data, BP risk factors, characteristics of BP and outcomes are analysed. Results One hundred and eighty-six BP episodes in 161 patients were included; patients were mainly male (73.7%) and intravenous drug users (73.7%). A decrease in BP incidence was seen during the study period, especially in vaccinated patients. The most commonly isolated microorganism was Streptococcus pneumoniae (31.7%), followed by Legionella pneumophila (5.9%). Legionella pneumophila was more likely in patients with undetectable viral load, higher CD4 cell counts or prior vaccination. Highly active antiretroviral therapy, cotrimoxazole prophylaxis and pneumococcal vaccination did not have a significant influence on bacteraemia rate, in-hospital complications or BP mortality. High Pneumonia Severity Index (PSI) predicted mortality accurately [relative risk 15.2, 95% confidence interval 3.2-71.7; P = 0.001]. Mortality was 9.1%, but was significantly higher in patients with CD4 counts under 200 cells/mu L (P = 0.022). Conclusions A decline in BP incidence was seen during the study period. Combining CD4 cell count and PSI score could become a good strategy in deciding which patients have to be hospitalized.