Predicting bacteremic pneumonia in HIV-1-infected patients consulting the ED

HIV-1-infected patients have higher incidence of community-acquired pneumonia (CAP) and risk of complications. Bacteremia has been associated with a higher risk of complications in such patients. We investigated factors associated with bacteremia in HIV-1-infected patients with CAP presenting at the emergency department.

We included HIV-1-infected patients with CAP for 3 years (March 2005-February 2008). Only patients in whom blood cultures were performed were finally included. Clinical data (age; sex; CD4(+) count; serum HIV viral load; previous or current intravenous drug use and antiretroviral treatment; systolic blood pressure; and cardiac and respiratory rates), analytical data (leukocyte count, arterial oxygen content, C-reactive protein value, and urgent Streptococcus pneumoniae and Legionella spp antigen urine detection), and APACHE-II (Acute Physiology and Chronic Health Evaluation) score were compiled. The need for intensive care unit admission, mechanical ventilation, mortality, and for patients finally discharged, duration of admission were retrospectively obtained from the clinical history. A multivariate analysis using logistic regression was performed to find independent predictors of bacteremia.

We diagnosed 129 HIV-1-infected patients with CAP. Blood cultures were performed in 118 cases (91%). Bacteremia was present in 28 (24%). Independent predictors of bacteremia were the detection of S pneumoniae antigen in urine (odds ratio, 9.0; 95% confidence interval, 1.9-42.0) and the absence of current antiretroviral treatment (odds ratio, 7.1; 95% confidence interval, 1.4-33.3). In-hospital mortality was higher in patients with bacteremia (15% vs 0%).

HIV-1-infected patients with CAP who are not on current antiretroviral therapy and have positive S pneumoniae antigenuria are at increased risk of having bacteremia. Bacteremic patients have a poor outcome.