Enteral vancomycin controls methicillin-resistant Staphylococcus aureus endemicity in an intensive care burn unit: a 9-year prospective study

Abstract

Objective: The aim of this study was to assess the efficacy and safety of enteral vancomycin in controlling MRSA endemicity in an intensive care burn unit.

Summary background data: MRSA is a serious clinical and epidemiologic problem. It is not uncommon that the traditional maneuvers, detection and isolation of carriers, fail to control endemicity due to MRSA.

Methods: All patients admitted to an Intensive Care Burn unit from January 1995 to February 2004 have been included in this prospective cohort study comprised 2 different periods. During period 1 (January 1995 to January 2000), barrier and isolation measures were enforced. During period 2 (February 2000 to February 2004), patients received enteral vancomycin 4 times daily in addition to selective digestive decontamination.

Results: A total of 777 patients were enrolled into the study: 402 in period 1, and 375 in period 2. There were no significant differences in the characteristics of patients between the 2 periods, except for the total body surface burned area, 30.3% in period 1 and 25.61% in period 2 (P = 0.009). There was a significant reduction in the incidence of patients who acquired MRSA from 115 in period 1 to 25 in period 2 (RR, 0.22; 95% confidence interval [CI], 0.15-0.34). Similar reductions were observed in the number of patients with wound (RR, 0.20; 95% CI, 0.12-0.32), blood (RR, 0.13; 95% CI, 0.04-0.35), and tracheal aspirate (RR, 0.07; 95% CI, 0.03-0.19), samples positive for MRSA. There was no emergence of either vancomycin-resistant enterococci or Staphylococcus aureus with intermediate sensitivity to glycopeptides in period 2.

Conclusions: Enteral vancomycin is an effective and safe method to control MRSA in intensive care burn units without VRE.

FIGURE 1. A, Cumulative incidence rate (acquired cases) of patients positive for MRSA (surveillance, burn wound, or diagnostic samples). B, Prevalence (imported cases) of patients positive for MRSA (surveillance, burn wound, or diagnostic samples).

FIGURE 2. A, Patients with acquired positive surveillance samples. B, Patients with acquired positive burn samples. C, Patients with acquired positive diagnostic samples. *Patients with acquired positive surveillance samples/total acquired samples. p25, percentile 25th; p50, median; p75, percentile 75th.

FIGURE 3. Cumulative risk of acquiring MRSA (Kaplan-Meier). Log rank text, P < 0.00001.