Clinical significance of methicillin-sensitive and methicillin-resistant Staphylococcus aureus in UK hospitals and the relevance of povidone-iodine in their control.

This review summarizes the natural history, clinical relevance and basis of control of Staphylococcus aureus infection in UK hospitals, stressing the central role of asymptomatic carriage by patients and staff in persistence of this prolific and versatile nosocomial pathogen. The clinical relevance of methicillin-resistant and methicillin-sensitive S. aureus (MRSA and MSSA) is considered in terms of prevalence and spectrum of invasive and toxigenic infections produced, correlated with host and parasite risk factors. An assessment is made of arguments why the acquisition of methicillin-resistance or multiple antibiotic resistance might justify more than conventional methods of containment and how the control policy is influenced by the expression of enhanced virulence and epidemicity. Guidelines for control of epidemic MRSA (EMRSA) are discussed with reference to justification, feasibility and efficacy. As elimination of carriage is crucial to the success of any rational control policy the relative merits of topical antibiotics and antiseptic agents are compared. The bacterial efficacy of povidone-iodine, chlorhexidine and mupirocin are evaluated as a basis for eradication of MRSA.