Rapid MRSA test in exposed persons: costs and savings in hospitals.
OBJECTIVE
To study a rapid Xpert polymerase chain reaction (PCR) method in detecting methicillin-resistant Staphylococcus aureus (MRSA) in patients and healthcare workers (HCW) exposed to MRSA, and to estimate savings associated to isolation or work restriction.


METHODS
A test set of four double (one for the growth and one for the rapid test) pre-wet swabs from the nose, throat, hands/wrists and perineum was studied by a growth method and by the Xpert MRSA test.


RESULTS
The total correspondence between the growth and the rapid test was 92.8%. The overall sensitivity, specificity, positive and negative predictive values were for the Xpert MRSA test: 87%, 99.6%, 68.5% and 99.9%, and for the growth test: 76%, 100%, 100%, and 99.8%, assuming a prevalence of MRSA of 0.01%. Among the MRSA positive persons, the Xpert and growth tests detected MRSA in 44.6% and 40% of nose samples, respectively, 38.2% and 45.5% throat samples, 30.8% and 11.5% hands/wrists samples, 44% and 38% perineum samples, and in 81.8% and 77.3% wound samples, respectively. By combining four anatomical sites, the detection rate increased to 87.5% by both methods. The cost for each Xpert and growth test was euro50 and euro6.25, respectively. The rapid test would save at least euro925 per exposed HCW and euro550 per patient that were MRSA negative.


CONCLUSIONS
The MRSA Xpert test is easy to perform, has a high negative predictive value, and may be used to control healthcare workers and patients exposed to MRSA. Sampling from multiple anatomical locations is recommended. Still, more then 10% of MRSA positive cases may not be found.
Andersen
B M
BM
Department of Hospital Infections, Oslo University Hospital - Ullevål, Oslo, Norway. bjorgmarit.andersen@ulleval.no
Tollefsen
T
T
Seljordslia
B
B
Hochlin
K
K
Syversen
G
G
Jonassen
T Ø
TØ
Rasch
M
M
Sandvik
L
L
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001431:Bacteriological Techniques / Q000191:economics* / Q000379:methods*; D002353:Carrier State / Q000175:diagnosis* / Q000382:microbiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D017048:Health Care Costs; D006761:Hospitals; D006801:Humans; D007223:Infant; D008297:Male; D008403:Mass Screening / Q000191:economics* / Q000379:methods*; D055624:Methicillin-Resistant Staphylococcus aureus / Q000302:isolation & purification*; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000191:economics / Q000379:methods; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D013203:Staphylococcal Infections / Q000175:diagnosis* / Q000382:microbiology; D013997:Time Factors; D055815:Young Adult