The impact of bacteraemia on HIV infection. Nine years experience in a large Italian university hospital.

The object of this case control study was to evaluate the frequency, the risk factors, the microbiological spectrum and the outcome of 249 cases of bacteraemia observed in 209 HIV-infected patients, most them affected by AIDS. The rate of bacteraemia in the total yearly HIV-related admissions increased from 4% in 1985 to 13% in 1993. The more common aetiological agents of bacteraemia were: Staphylococcus aureus (29.7%), non-typhoidal species of Salmonella (14.1%), Staphylococcus epidermidis (10.9%), Streptococcus pneumoniae (8.4%) and Pseudomonas aeruginosa (7.6%). A mixed flora was found in 14% of the episodes. Multivariate analysis of predisposing factors indicated that a low CD4+T-cell count (<0.2 x 10(9)/l) (P=0.01), use of central venous catheters (CVC) (P=0.01) and neutropenia (polymorphonuclear neutrophils <1.0 x 10(9)/l) (P=0.04) were independent risk factors for the development of bacteraemia. Logistic regression did not reveal any association of bacteraemia with intravenous drug abuse (on univariate analysis P=0.04). The response (31.8%). Recurrences to specific therapy was favourable in 170 episodes (68.2%); death occurred in 79 (31.8%). Recurrences arose in 40 patients, 17 (42.5%) of them died. The outcome of bacteraemia was influenced by a low number of CD4+T-cells (P<0.001) but not of polymorphonuclear cells. Our findings suggest that bacteraemia is a relatively common event in HIV-infected patients, especially under particular conditions (e.g. intravenous drug abuse, use of CVC, neutropenia and a low CD4-T-cell count). It requires special attention from physicians who must recognise and treat the condition promptly at an early stage.