Risk for Invasive MRSA Multiplied 100-Fold in Dialysis Patients

Risk for Invasive MRSA Multiplied 100-Fold in Dialysis Patients

Yael Waknine
Medscape Medical News

March 9, 2007 — The incidence of invasive methicillin-resistant Staphylococcus aureus (MRSA) is 100 times greater among dialysis patients compared with the general population, according to the results of a study published in the March 9 issue of the Morbidity and Mortality Weekly Report.

In the study, investigators analyzed data collected in 2005 by the Active Bacterial Core surveillance (ABCs) system from the entire state of Connecticut and 23 counties in 8 other states.

Overall results showed that 813 (15.4%) of 5287 reported invasive MRSA cases occurred in dialysis patients; the overall incidence was 45.2 cases per 1000 dialysis patients compared with 0.2 to 0.4 cases per 1000 general population.

The majority of infections (86%) were bloodstream infections, mainly occurring in patients with catheters (85%) or other invasive devices in place at the time; 90% required hospitalization and 17% died as inpatients.

The authors note that infections account for nearly 14% of deaths and represent the second most common cause of mortality in patients with end-stage renal disease, about 70% of whom require long-term dialysis treatment.

Although patients receiving hemodialysis are particularly vulnerable to vascular-access infections, catheters have the highest risk; intermediate risk for grafts; and the lowest risk was seen for arteriovenous fistulas. Minimizing long-term catheter use is therefore a basic strategy for preventing related bacteremias, including invasive MRSA infections, according to the authors.

Of 126 dialysis isolates in the study, microbiologic characterization revealed that 80% were strains of healthcare origin, with USA100 accounting for 92% of healthcare strains and 74% of all isolates. A further 14% were community strains, with USA300 representing 89% of these and nearly 13% of all isolates. Antibiotic susceptibility tests performed on 113 isolates showed that none were resistant to vancomycin, daptomycin, or linezolid.

According to the authors, treatment of hemodialysis-associated infections is a key factor in the increasing prevalence of antimicrobial resistance. MRSA strains of healthcare origin (eg, USA100) are typically multidrug resistant; 5 of the first 6 cases of vancomycin-resistant S aureus occurred in patients who had received dialysis and the first was reported in a hemodialysis patient.

To prevent the development of drug resistance among dialysis patients, healthcare providers are encouraged to follow guidelines from the Centers for Disease Control and Prevention's 12-step campaign available online at http://www.cdc.gov/drugresistance/healthcare/patients.htm#dialysis. Additional resources on preventing infection transmission in chronic hemodialysis patients are available at http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5005a1.htm.

URL: http://www.medscape.com/viewarticle/553441