Epidemiology of MRSA: the North/South study of MRSA in Ireland 1999.

The North/South Study of methicillin-resistant Staphylococcus aureus (MRSA) in Ireland, 1999, includes a joint review of the epidemiology of MRSA across both jurisdictions on the island of Ireland. Data were gathered on all MRSA cases identified in laboratories in Northern Ireland (the North) and in the Republic of Ireland (the South) over a two-week period. The prevalence rate per 100000 population was 11.4 in the North and 14.0 in the South, with a marked variation across geographical regions. MRSA cases were located throughout hospitals and the community, were slightly more common in males than females, and occurred in all age groups, especially in the elderly. The majority of cases were inpatients in acute hospitals and were distributed across all types of wards. Most cases were colonized with MRSA but 5% of cases in the North and 10% in the South had invasive infection. Invasive infection was associated with intravascular lines and invasive procedures/surgery. Continuous surveillance is recommended to monitor the epidemiology of MRSA and the effectiveness of control measures.