Meticillin-resistant Staphylococcus aureus – Community-acquired phenotype spread in hospitals in Bogotá, Colombia

Abstract number: P1438

Buitrago G., Cortes Luna J.A., Castillo Londoño J.S., Leal Castro A.L., Sanchez Pedraza R., Alvarez Moreno C.A.

Introduction: Meticillin Resistant Staphylococcus aureus (MRSA) has been largely known as a nosocomial microorganism with clonal dissemination. In Colombia, the Chilean clone has replaced the previous one as the most common cause of nosocomial infections in hospitals. Recently, isolates of community acquired MRSA (CA-MRSA) has been identified in Bogotá. The prevalence of CA-MRSA in colombian hospitals hasn't been reported. Here we show the observed change in the frequency of some phenotypes related to the Chilean and CA-MRSA clones and present a forecast for their behaviour.

Methods: Time-series analysis of MRSA isolates of 23 tertiary hospitals of the GREBO network between 2001 and 2006 was done. Microbiological data from hospitals were monthly transferred and compiled in the GREBO data base. A descriptive analysis of isolates susceptibility pattern was done with the Whonet (ver. 5.4) software. Two time-series anlalysis modelling were done by use of the Box-Jenkins methodology (72 monthly periods): One with the Chilean phenotype (Oxacillin, ciprofloxacin, erythromycin, clindamycin resistant, susceptible to cotrimoxazole, rifampin and tetracyclines) and one with the CA-MRSA phenotype (Oxacillin resistant susceptible to the others).

Results: 33156 S. aureus isolates were identified in the network. Annual frequency of MRSA starting 2001 was 38%, 46%, 45%, 45%, 38% and 34%. CA-MRSA phenotype showed an increase from 1% in 2001 to 5.4% in 2006. The Chilean clone series was best described by a simple exponential (alpha = 0.6677) and for the CA-MRSA phenotype the Brown lineal model fit better. The forecast for the Chilean clone phenotype doesn't show a clear cut trend (high confidence intervals). On the opposite, the forecast for the CA-MRSA phenotype series shows a high increase for the followingf year.

Time series and forecasting for Chilean and community-acquired MRSA clone.

Conclusions: CA-MRSA phenotype showed a sharp increase in the last years and the forecast predicts a higher percentage for the following year. The chilean clone seems to have a decrimental trend, but it is not as clear. This finding has a big impact on public health measures and medical education.

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Location: Barcelona, Spain
Presentation type:
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