Methicillin-resistant Staphylococcus aureus (MRSA) is an antibiotic resistant bacterium that can cause very serious, and at times fatal, infections. Antibiotic resistance is promoted by the misuse or overuse of antibiotics. MRSA has been found in high levels in healthcare facilities (such as hospital and nursing homes) but it can also be found in the community, outside of healthcare settings. “LabID Events” are MRSA infections that were identified in acute care hospital inpatients by counting culture samples tested by laboratories.

The Standardized Infection Ratio (SIR) is the primary measure used to track healthcare associated infections by the Connecticut Department of Public Health. The ratio is the number of actual infections that occur in a given time (called the baseline period) divided by the number predicted. The baseline is 1.0, which means that the number of infections observed is the same as the number predicted. If the SIR is greater than 1.0, it indicates that more HAIs were observed than predicted; conversely, an SIR less than 1.0 indicates that fewer HAIs were observed than predicted. As the aim is to reduce MRSA infection, we aim to reduce the SIR below 1 (the lower, the better).

In 2019, the Connecticut MRSA SIR increased to 0.80 from 0.74 in 2018, indicating the need for further prevention efforts. DPH looked further into the MRSA data from 2019, examining for concerning trends or clusters. We found that only a small number of MRSA infections that caused the rise in SIR, indicating that many facilities have adopted best practices to decrease infections. Of the 30 hospitals that reported MRSA infections, four had a MRSA SIR above 1. 

Hospital medical and non-medical staff, especially infection prevention and control staff (infection preventionists and hospital epidemiologists). Connecticut Hospital Association. Qualidigm, the Connecticut CMS Quality Improvement Organization (QIO). The Connecticut Healthcare Associated Infections Advisory Committee. The Connecticut Chapter of the Infectious Diseases Society of America (CIDS). Centers for Disease Control and Prevention, Division of Healthcare Quality and Prevention. National Healthcare Safety Network. Council of State and Territorial Epidemiologists. The Association of Professionals in Infection Control, Inc. The Society for Healthcare Epidemiology in America. Connecticut Department of Public Health.  

MRSA infections can be prevented by proper use of antibiotics, using them only when necessary and only to the extent needed. Antimicrobial (antibiotic) stewardship programs aim to accomplish this through careful tracking of antibiotic use, training of healthcare providers that prescribe antibiotics and patients about the need of proper antibiotic use, and limits on the use of certain antibiotics. MRSA infections can also be prevented by careful cleaning of the environment and careful handwashing by healthcare workers, especially in nursing homes and hospitals. To implement these practices, healthcare facilities must track use of the best practices, and ensure that all staff involved in prescribing antibiotics, direct patient contact, and cleaning of the healthcare facility rigorously adhere to them, despite the many competing priorities they address every day to care for patients.

Many facilities have adopted the best practices after participating in prevention collaboratives, where groups of different healthcare facilities meet to share ideas about how to implement and maintain best practices to prevent MRSA infections. We will continue to monitor the MRSA bacteremia LabID Event data, to assess the effectiveness of interventions aimed to prevent MRSA.