Hope Kirsty, Boyd Rowena, Conaty Stephen, Maywood Patrick
South Western Sydney and Sydney Local Health Districts Public Health Unit, New South Wales, Australia .
Western Pac Surveill Response J. 2012 Dec 20;3(4):33-8. doi: 10.5365/WPSAR.2012.3.3.009. Print 2012 Oct.
Seventeen cases of locally acquired measles occurred in South Western Sydney and Sydney local health districts between July and October 2011. Three of the cases were known to have at least one dose of measles-mumps-rubella (MMR) vaccine. Seven cases were infected within a health care setting waiting room by five index cases. Current national protocols require follow-up of all susceptible contacts in the same waiting room for any length of time for up to two hours after the index case has left.
Cases were interviewed using a standardized questionnaire. Information included: demographics, illness and activities during the exposure and infectious periods. Health care settings provided arrival and discharge times, maps of floor layouts and location of patients during stay.
All health care setting transmission occurred in cases who were present at the same time as their index cases, with crossover time ranging from 20 to 254 minutes. No index case was isolated. Index cases were between day four and six of illness when transmission occurred. None of the five index cases and one of seven secondary cases had received at least one dose of MMR vaccine. Of the seven secondary cases, two were one year of age, one was 17 years old and four were between 30 and 39 years old.
As Australia moves towards measles elimination, follow-up of cases is important; however, with limited public health resources a targeted response is vital. In this small but well documented series of secondary cases acquired in a health care setting, all were infected following direct, proximate contact of at least 20 minutes. Changes to the national guidelines may be warranted, ensuring that limited resources are focused on following up contacts at greatest risk of disease.
2011年7月至10月期间，悉尼西南部和悉尼地方卫生区发生了17例本地感染的麻疹病例。已知其中3例至少接种过一剂麻疹-腮腺炎-风疹（MMR）疫苗。7例病例在医疗机构候诊室被5例索引病例感染。目前的国家方案要求，在索引病例离开后，对同一候诊室的所有易感接触者进行长达两小时的随访，无论接触时间长短。
使用标准化问卷对病例进行访谈。信息包括：人口统计学、暴露期和传染期的疾病及活动情况。医疗机构提供了就诊和出院时间、楼层布局图以及患者住院期间的位置。
所有医疗机构内的传播均发生在与索引病例同时在场的病例中，交叉时间为20至254分钟。没有对索引病例进行隔离。传播发生时，索引病例处于发病后的第4至6天。5例索引病例中无一例以及7例二代病例中的1例接种过至少一剂MMR疫苗。7例二代病例中，2例为1岁，1例为17岁，4例年龄在30至39岁之间。
随着澳大利亚朝着消除麻疹的目标迈进，对病例的随访很重要；然而，由于公共卫生资源有限，有针对性的应对措施至关重要。在这一在医疗机构中发生的小型但记录详实的二代病例系列中，所有病例均在至少20分钟的直接、近距离接触后被感染。可能有必要对国家指南进行修订，以确保有限的资源集中用于对疾病风险最高的接触者进行随访。
