Clinical features and treatment outcomes of vancomycin-intermediate Staphylococcus aureus (VISA) and heteroresistant vancomycin-intermediate Staphylococcus aureus (hVISA) in a tertiary care institution in Singapore

Eur J Clin Microbiol Infect Dis. 2009 Aug;28(8):983-7. doi: 10.1007/s10096-009-0741-5. Epub 2009 Apr 22.

Abstract

This retrospective case-control study was undertaken to review the clinical features associated with heteroresistant vancomycin-intermediate Staphylococcus aureus (hVISA) and vancomycin-intermediate S. aureus (VISA) infections and the local impact they have on clinical outcome. Compared with vancomycin-susceptible S. aureus (n = 30), hVISA and VISA infections (n = 10) are found to be associated with a longer period of prior glycopeptide use (P = 0.01), bone/joint (P < 0.01) and prosthetic infections (P = 0.04), as well as treatment failure, as evidenced by longer bacteremic (P < 0.01) and culture positivity (P < 0.01) periods. This was observed to have resulted in longer hospital length of stay (P < 0.01) and total antibiotic therapy duration (P = 0.01). There was, however, no significant difference in the overall patient mortality or the hospitalization cost (P = 0.12) in both groups. Clinicians should be cognizant of the association between hVISA/VISA with high bacterial load deep-seated infections. We recommend targeted and even universal screening for hVISA/VISA in methicillin-resistant S. aureus (MRSA) infections.

MeSH terms

  • Adult
  • Aged
  • Anti-Bacterial Agents / therapeutic use*
  • Case-Control Studies
  • Female
  • Health Care Costs / statistics & numerical data
  • Hospitals
  • Humans
  • Length of Stay / statistics & numerical data
  • Male
  • Middle Aged
  • Retrospective Studies
  • Singapore
  • Staphylococcal Infections / drug therapy*
  • Staphylococcal Infections / economics
  • Staphylococcal Infections / microbiology
  • Staphylococcal Infections / mortality
  • Staphylococcus aureus / drug effects*
  • Staphylococcus aureus / isolation & purification
  • Treatment Failure
  • Treatment Outcome
  • Vancomycin Resistance*

Substances

  • Anti-Bacterial Agents