Gasch Oriol, Ayats Josefina, Ángeles Dominguez Maria, Tubau Fe, Liñares Josefina, Peña Carmen, Grau Immaculada, Pallarés Román, Gudiol Francesc, Ariza Javier, Pujol Miquel
From Infectious Diseases Service (OG, CP, IG, RP, FG, J. Ariza, MP) and Microbiology Service (J. Ayats, MAD, FT, JL), IDIBELL, Bellvitge University Hospital, University of Barcelona, Barcelona, Spain.
Medicine (Baltimore). 2011 Sep;90(5):319-327. doi: 10.1097/MD.0b013e31822f0b54.
Methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infection (BSI) is a cause of concern in health systems all over the world, due to the high incidence rates and the associated undesirable outcomes. In our tertiary 900-bed university hospital, all episodes of MRSA-BSI have been prospectively followed up since the identification of the first episode in 1990. We conducted the current study to report changes in the epidemiology of MRSA-BSI over the 19-year period between 1990 and 2008, comparing 4 periods (1990-1994, 1995-1999, 2000-2004, and 2005-2008). Overall, 524 patients developed MRSA-BSI. Cumulative incidence was 10.0 episodes/100,000 patient days (range, 1.3-17.4). Although no trend in the incidence rate was observed between the 4 consecutive periods, significant upward trends in patient age and comorbidities, health care acquisition, and non-intravascular catheter source were all identified (p < 0.05). While the Iberian clone (ST247/SCCmecI) was dominant during the first and second periods, almost all the strains isolated in the subsequent periods belonged to Clonal Complex 5 (ST125/SCCmecIV and ST228/SCCmecI). A significant downward trend in vancomycin geometric minimum inhibitory concentration (MIC) was also observed from 2.04 mg/L to 0.88 mg/L, coinciding with the clonal replacement and the reduction in the hospital vancomycin prescription. Therefore, no MRSA vancomycin MIC creep was observed since higher MICs were associated with strains belonging to the Iberian clone. Glycopeptides were the most frequently used antibiotics for MRSA-BSI during all 4 periods. No differences in MRSA-BSI outcomes were found, and the mortality rate at 30 days was close to 29% in each of the 4 periods. In conclusion, we identified significant changes in demographic and clinical characteristics and in the molecular epidemiology of MRSA-BSI during the study period, but found no significant trends in cumulative incidence or in overall mortality rate.
耐甲氧西林金黄色葡萄球菌（MRSA）血流感染（BSI）由于其高发病率及相关不良后果，已成为全球卫生系统关注的问题。在我们拥有900张床位的三级大学医院，自1990年发现首例MRSA-BSI病例以来，对所有病例均进行了前瞻性随访。我们开展本研究以报告1990年至2008年这19年间MRSA-BSI的流行病学变化，并比较4个时间段（1990 - 1994年、1995 - 1999年、2000 - 2004年和2005 - 2008年）的情况。总体而言，524例患者发生了MRSA-BSI。累积发病率为10.0例/100,000患者日（范围为1.3 - 17.4）。尽管在4个连续时间段内未观察到发病率的趋势，但患者年龄、合并症、医疗保健相关性及非血管内导管来源均呈现显著上升趋势（p < 0.05）。在第一和第二阶段，伊比利亚克隆株（ST247/SCCmecI）占主导地位，而在随后阶段分离出的几乎所有菌株都属于克隆复合体5（ST125/SCCmecIV和ST228/SCCmecI）。还观察到万古霉素几何最低抑菌浓度（MIC）从2.04 mg/L显著下降至0.88 mg/L，这与克隆替换及医院万古霉素处方量减少相吻合。因此，未观察到MRSA万古霉素MIC值升高的情况，因为较高的MIC值与属于伊比利亚克隆株的菌株相关。在所有4个时间段内，糖肽类抗生素是治疗MRSA-BSI最常用的抗生素。未发现MRSA-BSI结局存在差异，4个时间段内30天死亡率均接近29%。总之，我们发现在研究期间MRSA-BSI的人口统计学和临床特征以及分子流行病学发生了显著变化，但累积发病率或总体死亡率未发现显著趋势。
