WINNING THE BATTLE BUT LOSING THE WAR - METHICILLIN-RESISTANT STAPHYLOCOCCUS-AUREUS (MRSA) INFECTION AT A TEACHING HOSPITAL

A methicillin-resistant Staphylococcus aureus (MRSA) control policy, a imed at eradication, was established at a 1000-bed hospital in 1985, a pplied consistently for 10.5 years, and then relaxed. Its components i ncluded screening of high-risk patients, transfer of carriers to exhau st-ventilated isolation rooms, closure of wards to new admissions when local transmission was detected, MRSA screening during outbreaks, and prospective collection of clinical and epidemiological information. D uring the eradication policy period, every 6 months, a mean of 5.1 pat ients (range 1-12) already carrying MRSA were admitted, and a mean of 3.6 (range 0-16) acquired carriage in the hospital. The largest outbre ak comprised 11 patients despite epidemic MRSA strain EMRSA-16 being i ntroduced six times, and MRSA did not become endemic. MRSA-positive ad missions increased progressively from 1993; nursing staff workload inc reased, areas available for alternative patient accomodation were redu ced, the resulting ward closures interfered with clinical services, an d hence the control policy was relaxed in mid-1995. Isolation faciliti es were overwhelmed with 622 new patient-isolates in the next 18 month s, and there were 67 clinical infections in 1996. The proportion of bl ood cultures positive for MRSA rose nearly sevenfold by 1996 and 27-fo ld by 1997. Thus, repeated eradication of MRSA, even epidemic strains, by use of a stringent policy, is possible given sufficient resources, whereas flexible national guidelines designed to control, but not era dicate, epidemic staphylococci, are currently unlikely to be successfu l. The costs of eradication policies need to be weighed against those of endemicity.