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Invasive Methicillin Resistant Staphylococcus aureus (MRSA) Surveillance


To perform active population-based surveillance for invasive Staphylococcus aureus (iSA) infections in Monroe County, New York.

Goals and Objectives

  • MRSADocument the incidence and epidemiologic characteristics of invasive Methicillin-resistant S. aureus (MRSA) and Methicillin-sensitive S. aureus (MSSA) infections in diverse geographic areas in the United States and determine if the infection is Health Care-Associated (HA) or Community-Associated (CA).
  • Determine the molecular epidemiologic patterns and microbiologic characteristics of invasive MRSA.


Through partnership with local microbiology laboratories, weekly lists of potential iSA cases are received and reviewed. Data collected on confirmed cases includes demographics, patient outcomes, types of infections, and co-morbidities.

Cases are classified as CA or HA based on risk factors, allowing for tracking of trends in iSA epidemiology over time. Select MRSA isolates are sent to the state public health lab and CDC to identify trends in MRSA strain type.

Since 2012, the incidence of Hospital-onset (HO) MRSA has decreased substantially, likely due to national infection prevention efforts.  More robust prevention of MRSA in the hospitals has also likely caused a decrease in infections that develop in the community among individuals recently discharged from the hospital (HACO-MRSA).  Meanwhile, Community-associated (CA) MRSA incidence has remained relatively stable.

MRSA graph


  • See I, Wesson P, Gualandi N, Dumyati G, Harrison LH, Lesher L, Nadle J, Petit S, Reisenauer C, Schaffner W, Tunali A, Mu Y, Ahern J. Socioeconomic Factors Explain Racial Disparities in Invasive Community-Associated Methicillin-Resistant Staphylococcus aureus Disease Rates.  Clin Infect Dis. 2017;64(5):597-604.
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