MRSA improvement within a highly endemic hospital in Malta : infection control measures or clonal change?

Abstract

Malta has seen a significant reduction in the incidence of meticillin-resistant Staphylococcus aureus (MRSA) over the past decade. The primary contributor to this decline has been Mater Dei Hospital (MDH), a 1000-bed institution providing all tertiary and most secondary care in the country. Meticillin resistance in Staphylococcus aureus clinical isolates at MDH decreased from 51.4% [95% confidence interval (CI) 48.1–54.6%] in 2010 to 24.7% (95% CI 21.6–28.0%) in 2019. Over the same period, the incidence of healthcare-associated MRSA infections at MDH decreased from 1.1 to 0.18 cases per 1000 bed-days. This development runs contrary to the trend in European Union countries, where MRSA infections increased overall by 1.28% between 2007 and 2015. This is particularly the case in the Mediterranean region. The reduction in the incidence of MRSA at MDH corresponded with the introduction of a universal MRSA admission screening and decolonization strategy in 2014, wherein all patients admitted to adult hospital wards were screened by means of a nasal swab taken within 24 h of admission. If carriage was detected, they were decolonized with a 5-day combination of intranasal mupirocin and chlorhexidine body washes. The use of both agents has been substantial, with an average of 8.3% (interquartile range 6.8–9.6%) of admissions testing positive and requiring decolonization.