488. Is PCR Better Than Culture For MRSA Surveillance in the ICU?
Session: Poster Session: Hospital-acquired and Transplant Infections
Friday, October 30, 2009: 12:00 AM
Room: Poster Hall A
Background: Use of the more expensive PCR over traditional culture methods to detect MRSA carriage has been gaining popularity secondary to rapid turnaround times(90 minutes). We compared the impact of both methods on detection of new cases and infections in the ICU.
Methods: As per the VHA directive of January 2007, all patients who were admitted to and transferred from our medico-surgical 10 bed ICU had nasal, pharyngeal and perineal surveillance swabs with the intent to interrupt the chain of transmission of MRSA and to decrease the number of patients at risk for infection. Cases were classified as prevalent based on the following : MRSA was recovered within 48 hours after admission or the patient was previously known to be positive. MRSA cases that did not meet either criterion were classified as incident cases.Infection rates defined per CDC. All patients admitted to the VA ICU between March 18 2008 and Dec 18 2008 were screened using Cepheid PCR. From October 2006 to February 2008 patients were screened with Culture or Chromager and after December 2008 patients were screened with Cepheid PCR or Chromager. Time to reporting was calculated on the culture positive cases as the time the specimen was recieved in the laboratory to the time of notification to Infection Control.The time to reporting of culture positive cases, incidence and infection rates during the PCR months and Culture months were calculated.Two sample T test was performed with Stata.
Results: The median time to reporting of culture positives was 50.3 hours, SD +/-20.3 hours.The mean incidence of MRSA during PCR months was 2.2+/- 0.63 SD ( 1.74-2.65 95% C.I.) vs 2.2 +/-1.47 (1.73-2.66 95% C.I.)during Culture months (P=0.5).The ICU admission rate during PCR months was 39.5 +/- 6.27 (35.01-43.98 95% C.I.) vs 38.65 +/- 5.82 (36.7-41.12 95% C.I.) during Culture months (P=0.7).The mean MRSA infection rates during PCR months was 0.5+/-0.53SD (95% C.I.= 0.12-0.88) vs 0.4+/-0.5SD(0.17-0.63 95% C.I.) during Culture months(P=0.6)
Conclusion: Despite the longer turnaround time of culture results no significant impact of PCR was observed in detection,incidence and infection rates of MRSA in the ICU.
Lisa Bailey, RN, MS, BSN1, Victor Jimenez, MD2, Michael Shulman, MS3, Shantala Subramanyam, MD2 and  S. Subramanyam, None..
V. Jimenez, None..
L. Bailey, None..
M. Shulman, None., (1)VAMC, Northport, NY, (2)Stonybrook University Medical Center, Stonybrook, NY, (3)Microbiology, Northport VA Medical center, Northport, NY