Nosocomial infections in HIV-infected patients: preliminary results from a multicenter surveillance system (1989-1995).

Abstract

To describe the characteristics of and trends in nosocomial infection among human immunodeficiency virus (HIV)-infected patients. Multicenter prospective cohort study. HIV-infected patients were enrolled at time of first inpatient admission at five Veterans' Administration Medical Centers (VAMCs). As of March 1995, 2,541 patients with 6,625 inpatient admissions had been monitored in the five VAMCs. A total of 530 nosocomial infections were detected using standard Centers for Disease Control and Prevention definitions. Overall distribution by infection site was 31% for primary bloodstream infections (BSIs), 28% for urinary tract infections, 15% for pneumonia, and 26% for all other sites. Of BSIs, 63% were central line-associated bloodstream infections (CLABs). The rate of CLABs per 1,000 central line days was 6.5 (range, 2.3-8.3) for all patients from participating hospitals, similar to the median CLAB rate of 6.0 for patients in medical intensive-care units (ICUs) of National Nosocomial Infections Surveillance (NNIS) System hospitals from January 1990 through September 1994. For ICU-specific CLABs, the rate from hospitals reporting at least one ICU CLAB was 12.7 (range, 12.1-13.1), comparable to the 90th percentile of NNIS hospital medical ICUs (13.1). Staphylococcus aureus, associated with 35% of BSIs, was the most common nosocomial BSI pathogen. Our data demonstrated the following: 13 (10%) of 134 patients with CD4 counts > or = 200 cells/mm3 had a CLAB, compared with 61 (6%) of 1,011 patients with CD4 counts < 200 cells/mm3, P = .08; the per-day risk of CLABs did not change with increased duration of catheterization (P = .4); and the per-day risk of a temporary (ie, short-term) CLAB was greater than that of a permanent CLAB (P < .001). The data suggest that HIV-infected patients were at higher risk of acquiring a BSI than were patients in the NNIS population; patients with CD4 counts > or = 200 cell/mm3 and temporary central lines were at increased risk for BSI, perhaps reflecting widespread prophylaxis with trimethoprim-sulfamethoxazole among patients with CD4 counts < 200 cells/mm3, and, in contrast to most studies, S aureus, not coagulase-negative Staphylococcus, was the most common BSI pathogen.