Background

methicillin-susceptible Staphylococcus aureus (MSSA) bloodstream infection rates have risen steadily in recent years, with a marked decline in the corresponding rates due to methicillin-resistant S. aureus (MRSA). Screening for MSSA carriage is not routinely undertaken and MRSA screening is not universal, thus the extent of S. aureus colonization pressure in nosocomial settings is unknown.

Methods

We conducted a prospective, observational study of patients and healthcare workers (HCWs) across nine inpatient wards in a tertiary referral hospital over a two-year period. Participants were screened for MSSA and MRSA using nasal swabs and oral rinses. Environmental surfaces and air were also tested for S. aureus using contact plates and active air sampling.

Findings

We enrolled 388 patients and 326 HCWs; and took 758 contact plate samples from surfaces and 428 air samples. MSSA was recovered from 24% of patients, 31.3% of HCWs, 16% of air samples and 7.9% of surface samples. MRSA was recovered from 6.4% of patients, 3.7% of HCWs, 2.5% of air samples and 2.2% of surface samples. Inclusion of the oral cavity in addition to the anterior nares in the sampling regimen identified 30 patients and 36 HCWs who exhibited exclusive oral colonization.

Conclusions

The oral cavity comprises a significant nosocomial reservoir for S. aureus that is currently under-appreciated. Oral screening should be considered both in terms of the colonization pressure in a healthcare facility, and on an individual patient level, especially in patients where decolonization attempts have repeatedly failed and in those undergoing high-risk procedures.

中文翻译：

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大量患者、医护人员和环境采样显示，一家急症医院的口腔是金黄色葡萄球菌的重要储存库

 背景

近年来，甲氧西林敏感金黄色葡萄球菌（MSSA）血流感染率稳步上升，而耐甲氧西林金黄色葡萄球菌（MRSA）导致相应率明显下降。 MSSA 携带筛查并不常规进行，MRSA 筛查也不普遍，因此医院环境中金黄色葡萄球菌定植压力的程度尚不清楚。

 方法

我们对一家三级转诊医院的九个住院病房的患者和医护人员 (HCW) 进行了一项为期两年的前瞻性观察性研究。使用鼻拭子和口腔冲洗液对参与者进行 MSSA 和 MRSA 筛查。还使用接触板和主动空气采样来测试环境表面和空气中的金黄色葡萄球菌。

 发现

我们招募了 388 名患者和 326 名医护人员；并从表面采集了 758 个接触板样本和 428 个空气样本。从 24% 的患者、31.3% 的医护人员、16% 的空气样本和 7.9% 的表面样本中回收到了 MSSA。从 6.4% 的患者、3.7% 的医护人员、2.5% 的空气样本和 2.2% 的表面样本中检出 MRSA。取样方案中除前鼻孔外还包括口腔，确定了 30 名患者和 36 名医护人员表现出独特的口腔定植。

 结论

口腔是金黄色葡萄球菌的重要医院储存库，但目前人们对其的认识不足。口腔筛查应同时考虑医疗机构中的定植压力和患者个体水平，特别是对于去定植尝试多次失败的患者以及接受高风险手术的患者。