Prevention of Staphylococcus aureus infections among surgical patients: beyond traditional perioperative prophylaxis

Health care-related infections cause significant patient morbidity and mortality rates and add excess costs that frequently are not reimbursed. Staphylococcus aureus has long been recognized as an important pathogen in human disease and is the most common cause of nosocomial infections.

The objective of this review of the English language literature and a MEDLINE search was to describe recent advances in the prevention of S aureus health care-related infections that are attributable to patients' endogenous colonization. The ecologic niche of S aureus is the anterior nares and nasal carriage increases the risk of the development of a surgical-site, lower respiratory tract, or bloodstream infection. S aureus carriers have a 2- to 9-fold increased risk of the development of a surgical-site or intravenous catheter infection.

Three treatment strategies may eliminate nasal carriage: locally applied antibiotics or disinfectants, systemic antibiotics, and bacterial interference. Among these strategies, locally applied or systemic antibiotics are used most commonly. Nasal ointments or sprays and oral antibiotics have variable efficacy, and their use frequently results in antimicrobial resistance among S aureus strains. Of the commonly used agents, mupirocin (pseudomonic acid) ointment has been shown to be 97% effective in reducing S aureus nasal carriage. In a recently published randomized, double-blind, placebo-controlled trial to determine whether intranasal mupirocin reduced the rate of S aureus-infected surgical-site and other S aureus health care-related infections; 4% of S aureus nasal carriers who received mupirocin acquired S aureus health care-related infections compared with 7.7% of S aureus nasal carriers who received placebo (P=.02). The S aureus surgical-site infection rate was not reduced significantly, but carriers who received mupirocin before cardiothoracic or general surgery operations had almost 50% fewer S aureus surgical-site infections than carriers who received placebo. In this setting resistance rarely has been reported.

Given the importance of S aureus nosocomial infections and the increased risk of S aureus nasal carriage in patients with health care-related infections, investigators must study cost-effective strategies to further prevent certain types of health care-related infections or nosocomial infections that occur in specific settings. One potential strategy is to decrease or eliminate S aureus nasal carriage among certain patient populations or in certain healthcare settings.