UK Field Epidemiology Training Programme, Public Health England, London, UK; Field Service, North East, and Yorkshire and Humber, National Infection Service, Public Health England, Newcastle upon Tyne, UK.
National Infection Service, Public Health England, Healthcare Associated Infection - Antimicrobial Resistance, Staphylococcus Reference Section, London, UK.
J Hosp Infect. 2020 Dec;106(4):774-781. doi: 10.1016/j.jhin.2020.09.029. Epub 2020 Oct 1.
Between August 2016 and November 2019, a cluster of babies colonized with meticillin-resistant Staphylococcus aureus (MRSA) was reported in a special care baby unit in northern England.
A case-control study was performed to identify the source and prevent further cases.
Cases were admitted neonates colonized or infected with MRSA (spa type t316). A retrospective case-control study was performed with two matched controls per case. Exposures were determined by medical record review. Cases were compared with controls using conditional logistic regression. Environmental investigations and staff screening were undertaken.
Thirty-one colonized cases were identified across the 3-year period, with no infections reported. Thirteen of the 31 cases were sequenced and were within a cluster of 25 single nucleotide polymorphisms, consistent with exposure to a common source over a prolonged period. Most MRSA cases had a prior negative screen (N=22, 71%). Environmental sampling and staff screening were performed on several occasions. In the analytical study, 31 cases were compared with 62 controls. One ward location and one healthcare worker were identified as significant exposures in the multi-variable analysis.
Due to the sporadic nature of the colonizations, it was hypothesized that MRSA was being introduced intermittently, likely by a colonized healthcare worker, with possible transmission between infants also occurring within each temporal cluster. It is recommended that transiently colonized healthcare workers should be considered as a source of MRSA during outbreaks. This study highlights the importance of analytic epidemiological studies in persistent outbreaks of MRSA.
2016 年 8 月至 2019 年 11 月，在英格兰北部的一家特护婴儿病房中报告了一组耐甲氧西林金黄色葡萄球菌（MRSA）定植的婴儿病例。
进行病例对照研究以确定来源并防止进一步发生病例。
病例为定植或感染 MRSA（spa 型 t316）的新生儿。对 31 例定植病例进行回顾性病例对照研究，每例病例匹配 2 例对照。通过病历回顾确定暴露情况。采用条件逻辑回归比较病例与对照。进行环境调查和员工筛查。
在 3 年期间共发现 31 例定植病例，未报告感染病例。13 例病例进行了测序，均属于 25 个单核苷酸多态性簇，提示暴露于共同来源的时间较长。大多数 MRSA 病例之前的筛查结果为阴性（N=22，71%）。多次进行了环境采样和员工筛查。在分析性研究中，31 例病例与 62 例对照进行了比较。多变量分析发现一个病房位置和一名医护人员是显著暴露因素。
由于定植的散发性，推测 MRSA 间歇性地传入，可能是由定植的医护人员引起，在每个时间集群内婴儿之间也可能发生传播。建议在暴发期间将暂时性定植的医护人员视为 MRSA 的来源。本研究强调了在 MRSA 持续暴发中进行分析性流行病学研究的重要性。
