Molecular epidemiology and control of nosocomial methicillin-resistant Staphylococcus aureus infection in a teaching hospital.
OBJECTIVE
Nosocomial methicillin-resistant Staphylococcus aureus (MRSA) infection is difficult to control. Due to a dramatic increase in the nosocomial MRSA infection rate at our hospital from 2000 to 2001, this study was conducted to identify the source of these infections and the effectiveness of control measures.


METHODS
179 healthcare workers (HCWs) were screened for carriage of MRSA. Starting in April 2001, all patients with MRSA infection or colonization were put in strict contact and cohort isolation. The bacterial isolates of HCW carriers and patients with MRSA infection from April 2001 to September 2001 were subjected to antimicrobial susceptibility testing by disk-diffusion method and molecular typing by pulsed-field gel electrophoresis (PFGE).


RESULTS
Fifteen HCWs were found to be carriers of MRSA. They were all given topical mupirocin treatment. After these interventions, the nosocomial MRSA infection rate decreased from 1.23 to 0.53 per 1000 patient-days. All 61 MRSA isolates available for antimicrobial susceptibility testing and molecular typing were multidrug resistant. PFGE study revealed 2 predominant types, type C and type Y, comprising 36 and 12 isolates, respectively.


CONCLUSIONS
The current study demonstrates the importance of measures to control nosocomial MRSA infections in hospitals that already have a high incidence of endemic MRSA infection. Elimination of carriage by healthcare workers, and strict contact and cohort isolation are the main effective measures.
Wang
Jann-Tay
JT
Division of Infectious Diseases, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
Lin
Sheng-Fong
SF
Chiu
Hsu-Ling
HL
Wang
Li-Chen
LC
Tai
Hui-Ming
HM
Jiang
Chaw-Fung
CF
Chang
Shan-Chwen
SC
Chu
Shu-Hsun
SH
D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D003428:Cross Infection / Q000453:epidemiology / Q000517:prevention & control*; D006784:Hospitals, Teaching; D006801:Humans; D017053:Infection Control / Q000379:methods; D017757:Infectious Disease Transmission, Professional-to-Patient / Q000517:prevention & control*; D016106:Methicillin Resistance; D016712:Mupirocin / Q000627:therapeutic use; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000517:prevention & control*; D013211:Staphylococcus aureus; D013624:Taiwan / Q000453:epidemiology
D000900:Anti-Bacterial Agents; D016712:Mupirocin