Despite the perception that meticillin-resistant Staphylococcus aureus (MRSA) is now under control in high-income countries, global prevalence remains high, even increasing in some regions. Universal admission screening and decolonization has been instituted in some hospitals to attempt control but the practice remains controversial.

In 2014, Mater Dei Hospital in Malta introduced a universal admission screening policy, utilizing a novel, centralized and customized approach to achieve high compliance and low cost. Admissions are screened nasally by designated staff using chromogenic media, irrespective of risk factors. Carriers are decolonized without concurrent isolation or contact precautions. In this study, longitudinal, quasi-experimental evaluation was undertaken using time series analysis to analyse the impact of the intervention on the proportion of MRSA among clinical S. aureus isolates (%MRSA) and incidence per 1000 bed-days. A cost–utility analysis was also attempted to identify approximate quality-adjusted life years (QALYs) gained.

A transfer function model approach concluded that the intervention had a significant effect on both %MRSA and incidence. Six years following its introduction, the screening programme had led to an overall 43% long-term reduction in %MRSA from pre-screening levels [R²=0.687; Bayesian information criterion (BIC)=4.063], translating to a decrease in incidence of approximately 0.56 cases/1000 bed-days (R²=0.633, BIC=-3.063). No correlation was identified with consumption of antibiotics or alcohol hand rub. The annual cost–benefit of the programme was calculated at €1058 per QALY gain per year.

The universal admission screening and decolonization intervention was successful and cost-effective in this high-endemicity setting. It facilitated improvement in the prevalence of MRSA, achieving reduction levels rarely reported by Mediterranean hospitals.