Classically, infections have been considered either nosocomial or community-acquired. Healthcare-associated infection represents a new classification intended to capture patients who have infection onset outside the hospital, but who, nonetheless, have interactions with the healthcare system. Regarding bloodstream infection (BSI), little data exist differentiating healthcare-associated bacteremia (HCAB) from community-acquired bacteremia (CAB). We studied the epidemiology and outcomes associated with HCAB.
We conducted a multicenter, retrospective chart review at 7 US hospitals, of consecutive patients admitted with a BSI during 2006, who met pre-defined selection criteria. We defined HCAB as a BSI in a patient who met ≥ 1 of the criteria: 1) hospitalization within 6 months; 2) immunosuppression;3) chronic hemodialysis; or 4) nursing home residence. The rest were classified as CAB. We examined patient demographics, severity of illness, and crude in-hospital mortality rates by HCAB vs. CAB status.
Of the total 1,212 patients included, HCAB accounted for 62.6%, with the percentage ranging from 48.0% to 77.6% across centers. HCAB patients were older (58.3 ± 17.6 vs. 54.9 ± 19.7 years, p = 0.003) and slightly more likely to be female (65.1% vs. 59.9%, p = 0.062) than those with CAB. HCAB was associated with a higher mean Acute Physiology Score (12.4 ± 6.3 vs. 11.2 ± 5.7, p = 0.004) and a higher rate of ICU admission (35.7% vs. 29.5%, p = 0.026) than CAB. Patients with HCAB were nearly 3 times as likely as patients with CAB to die during the hospitalization (odds ratio: 2.94, 95% CI: 1.86–4.79, p < 0.001).
HCAB accounts for a substantial proportion of all patients with BSIs admitted to the hospital. HCAB appears to present as a more severe infection and is associated with a higher unadjusted mortality rate than CAB.
Physicians should recognize that HCAB is responsible for many BSIs presenting to the hospital and may represent a distinct clinical group from CAB.
Andrew Shorr, Grant monies (from industry related sources) Research grant from Ortho-McNeil Janssen Scientific Affairs, LLC; Shareholder Shareholder in Johnson&Johnson; Consultant fee, speaker bureau, advisory committee, etc. I am a consultant to Ortho-McNeil Janssen Scientific Affairs, LLC; No Product/Research Disclosure Information