School of Mathematical Sciences, University of Nottingham, Nottingham, UK.
J Hosp Infect. 2011 Nov;79(3):222-6. doi: 10.1016/j.jhin.2011.05.008. Epub 2011 Jul 16.
Antibiotics and antiseptics have the potential to influence carriage and transmission of meticillin-resistant Staphylococcus aureus (MRSA), although effects are likely to be complex, particularly in a setting where multiple agents are used. Here admission and weekly MRSA screens and daily antibiotic and antiseptic prescribing data from 544 MRSA carriers on an intensive care unit (ICU) are used to determine the effect of these agents on short-term within-host MRSA carriage dynamics. Longitudinal data were analysed using Markov models allowing patients to move between two states: MRSA positive (detectable MRSA carriage) and MRSA negative (no detectable carriage). The effect of concurrent systemic antibiotic and topical chlorhexidine (CHX) on movement between these states was assessed. CHX targeted to MRSA screen carriage sites increased transition from culture positive to negative and there was also weaker evidence that it decreased subsequent transition from negative back to positive. In contrast, there was only weak and inconsistent evidence that any antibiotic influenced transition in either direction. For example, whereas univariate analysis found quinolones to be strongly associated with both increased risk of losing and then reacquiring MRSA carriage over time intervals of one day, no effect was seen with weekly models. Similar studies are required to determine the generalisability of these findings.
抗生素和防腐剂有可能影响耐甲氧西林金黄色葡萄球菌（MRSA）的携带和传播，尽管其影响可能很复杂，尤其是在使用多种药物的情况下。在这里，我们使用了来自重症监护病房（ICU）的 544 名 MRSA 携带者的入院和每周的 MRSA 筛查以及每日抗生素和防腐剂处方数据，以确定这些药物对宿主内 MRSA 携带动力学的短期影响。使用马尔可夫模型对纵向数据进行了分析，允许患者在两种状态之间移动：MRSA 阳性（可检测到 MRSA 携带）和 MRSA 阴性（未检测到携带）。评估了同时使用全身抗生素和局部洗必泰（CHX）对这些状态之间转移的影响。针对 MRSA 筛查携带部位的 CHX 增加了从培养阳性到阴性的转变，并且还有较弱的证据表明它降低了随后从阴性再次转为阳性的可能性。相比之下，几乎没有证据表明任何抗生素会影响任何方向的转变。例如，单变量分析发现喹诺酮类药物与在一天的时间间隔内，MRSA 携带的丢失和重新获得的风险增加强烈相关，但每周模型并未发现任何影响。需要进行类似的研究来确定这些发现的普遍性。
