Spread of Staphylococcus aureus in hospitals: Causes and prevention

Methicillin-resistant Staphylococcus aureus (MRSA) has become a major nosoc omial pathogen in many hospitals worldwide. Even more alarming, MRSA strain s that are vancomycin intermediate-susceptible are isolated with increasing frequency, making therapy for staphylococcal infections even more difficul t and prevention more important than er er. Spread of S. aureus in hospital s and infection control measures are reviewed. The major sources of S. aure us in hospitals are septic lesions and carriage sites of patients and perso nnel. Carriage often precedes infection. The anterior nares are the most co nsistent carriage site, followed by the perineal area. Skin contamination a nd aerial dissemination vary markedly between carriers and are most pronoun ced for combined nasal and perineal carriers. The principal mode of transmi ssion is via transiently contaminated hands of hospital personnel. Airborne transmission seems important in the acquisition of nasal carriage. Infecti on control strategies include screening and isolation of newly admitted pat ients suspected of carrying MRSA or S. aureus with intermediate resistance to vancomycin, implementation of an infection control program to prevent tr ansmission of resistant strains between patients and hospital personnel, an d institution of a proper antibiotic policy to minimize antibiotic resistan ce development. MRSA carriers should be treated with intranasal antibiotics , e.g. mupirocin, and skin disinfectants to eliminate carriage. Education o f hospital personnel is essential. Improved knowledge about the best ways t o ensure favourable infection control practices is needed. Active intervent ion against the spread of MRSA is important.