Sherertz R J, Reagan D R, Hampton K D, Robertson K L, Streed S A, Hoen H M, Thomas R, Gwaltney J M
Bowman Gray School of Medicine and North Carolina Baptist Hospitals, Inc. Winston-Salem, North Carolina, USA.
Ann Intern Med. 1996 Mar 15;124(6):539-47. doi: 10.7326/0003-4819-124-6-199603150-00001.
Nasal carriage of Staphylococcus aureus is common among health care workers, but outbreaks caused by such carriers are relatively uncommon. We previously reported outbreaks of S. aureus skin infections that affected newborn infants and were attributed to an S. aureus nasal carrier who had had an associated upper respiratory tract infection (UR) during the outbreak period.
To investigate the contribution of a nasal methicillin-resistant S. aureus (MRSA) carrier (physician 4) who contracted a URI to an outbreak of MRSA infections that involved 8 of 43 patients in a surgical intensive care unit during a 3-week period.
An epidemiologic study of an outbreak of MRSA infections and a quantitative investigation of airborne dispersal of S. aureus associated with an experimentally induced rhinoviral infection.
A university hospital.
43 patients in a surgical intensive care unit and 1 physician.
Molecular typing was done, and risk factors for MRSA colonization were analyzed. Agar settle plates and volumeric air cultures were used to evaluate the airborne dispersal of S. aureus by physician 4 before and after a rhinoviral infection and with or without a surgical mask.
A search for nasal carriers of MRSA identified a single physician (physician 4); molecular typing showed that the MRSA strain from physician 4 and those from the patients were identical. Multivariate logistic regression analysis identified exposure to physician 4 and duration of ventilation as independent risk factors for colonization with MRSA (P < or = 0.008). Air cultures showed that physician 4 dispersed little S. aureus in the absence of a URI. After experimental induction of a rhinovirus URI, physician 4's airborne dispersal of S. aureus without a surgical mask increased 40- fold; dispersal was significantly reduced when physician 4 wore a mask (P < or = 0.015).
Physician 4 became a "cloud adult," analogous to the "cloud babies" described by Eichenwald and coworkers who shed S. aureus into the air in association with viral URIs. Airborne dispersal of S. aureus in association with a URI may be an important mechanism of transmission of S. aureus.
医护人员鼻腔携带金黄色葡萄球菌很常见，但由此类携带者引起的暴发相对少见。我们之前报道过金黄色葡萄球菌皮肤感染暴发，感染对象为新生儿，病因是一名鼻腔携带金黄色葡萄球菌的医护人员，其在暴发期间伴有上呼吸道感染（URI）。
调查一名感染URI的耐甲氧西林金黄色葡萄球菌（MRSA）鼻腔携带者（医生4）对一次MRSA感染暴发的影响，此次暴发在3周内累及了外科重症监护病房43名患者中的8名。
一项关于MRSA感染暴发的流行病学研究，以及一项对与实验性诱导鼻病毒感染相关的金黄色葡萄球菌空气传播的定量调查。
一家大学医院。
外科重症监护病房的43名患者和1名医生。
进行分子分型，并分析MRSA定植的危险因素。使用琼脂沉降平板和大容量空气培养法评估医生4在鼻病毒感染前后以及佩戴或不佩戴外科口罩情况下金黄色葡萄球菌的空气传播情况。
对MRSA鼻腔携带者的筛查发现了一名医生（医生4）；分子分型显示医生4的MRSA菌株与患者的菌株相同。多因素逻辑回归分析确定接触医生4和通气持续时间是MRSA定植的独立危险因素（P≤0.008）。空气培养显示，在没有URI的情况下，医生4传播的金黄色葡萄球菌很少。在实验性诱导鼻病毒URI后，医生4不戴外科口罩时金黄色葡萄球菌的空气传播增加了40倍；当医生4佩戴口罩时，传播显著减少（P≤0.015）。
医生4成为了一个“播散成人”，类似于Eichenwald及其同事描述的“播散婴儿”，他们在病毒性URI期间将金黄色葡萄球菌散播到空气中。与URI相关的金黄色葡萄球菌空气传播可能是金黄色葡萄球菌传播的一个重要机制。
