Vancomycin-intermediate Staphylococcus Aureus, and Vancomycin-resistant Staphylococcus Aureus (VISA/VRSA)

2010 Case Definition

CSTE Position Statement Number: 09-ID-58 (VISA); 09-ID-59 (VRSA)

Clinical Description

Staphylococcus aureus can produce a variety of syndromes with clinical manifestations including skin and soft tissue infections, empyema, bloodstream infection, pneumonia, osteomyelitis, septic arthritis, endocarditis, sepsis, and meningitis. S. aureus may also colonize individuals who remain asymptomatic. The most frequent site of S. aureus colonization is the nares.

Laboratory Criteria

Case Classification

Confirmed: A case of vancomycin-intermediate or vancomycin-resistant S. aureus that is laboratory-confirmed (MIC = 4–8 µg/ml for VISA and MIC ≥ 16 µg/ml for VRSA).

Case Classification Table

Criterion Confirmed VISA Confirmed VRSA
Laboratory Findings
Isolation of S. aureus from any body site N N
Resistance of the S. aureus isolate to vancomycin (Minimum Inhibitory Concentration [MIC] ≥ 16 µg/ml) N
Intermediate resistance of the S. aureus isolate to vancomycin (Minimum Inhibitory Concentration [MIC] 4–8 µg/ml) N

Notes:

N = This criterion in conjunction with all other “N” criteria in the same column is required to report a case.

= detected and defined according to Clinical and Laboratory Standards Institute approved standards and recommendations (CLSI 2006).

Date Updated: