Belongia E A, Osterholm M T, Soler J T, Ammend D A, Braun J E, MacDonald K L
Acute Disease Epidemiology Section, Minnesota Department of Health, Minneapolis 55440.
JAMA. 1993 Feb 17;269(7):883-8.
Escherichia coli O157:H7 infection can cause hemorrhagic colitis and hemolytic uremic syndrome. Since 1988 the Minnesota Department of Health has carried out surveillance for this infection. To assess the occurrence of person-to-person transmission within day-care facilities, we investigated facilities where an infected child attended after onset of symptoms.
Parents of children less than 5 years old with E coli O157:H7 infection were interviewed from July 1988 through December 1989. If the child attended day care after onset, stool cultures were obtained from other children in attendance and their parents were interviewed. If there was presumptive evidence of ongoing E coli O157:H7 transmission in a facility, all preschool children were excluded from attending day-care facilities until two consecutive stool cultures were negative.
Sixty-eight cases of E coli O157:H7 infection were identified in Minnesota during the 18-month period, including 29 cases identified through investigations at nine day-care facilities. There was evidence of person-to-person transmission in all nine facilities. The median number of infected children per facility was two (range, two to 18), and the median attack rate was 22% (range, 3% to 38%). The median age of the primary case at each facility was 26 months (range, 12 to 59 months). There was no evidence of further transmission at facilities where children were temporarily excluded until two consecutive stool cultures were negative.
Person-to-person transmission of E coli O157:H7 is common when infected preschool children attend day care while symptomatic. The number of unrecognized day-care outbreaks in the United States may be substantial due to the lack of routine testing for this pathogen in stool cultures, the absence of public health surveillance in many regions, and incomplete follow-up of infected children. Temporary exclusion of all children was an effective control strategy in this population, but additional investigations are needed to determine the optimal intervention.
大肠杆菌O157:H7感染可导致出血性结肠炎和溶血性尿毒综合征。自1988年以来，明尼苏达州卫生部一直在对这种感染进行监测。为评估日托机构内的人际传播情况，我们对有症状感染儿童发病后所 attended的机构进行了调查。
1988年7月至1989年12月，对5岁以下感染大肠杆菌O157:H7的儿童的父母进行了访谈。如果儿童发病后 attended日托，采集了其他 attending儿童的粪便培养物，并对其父母进行了访谈。如果有证据表明某机构内存在大肠杆菌O157:H7的持续传播，所有学龄前儿童在连续两次粪便培养结果为阴性之前被排除在日托机构之外。
在这18个月期间，明尼苏达州共确诊68例大肠杆菌O157:H7感染病例，其中29例是通过对9所日托机构的调查确诊的。所有9所机构均有人际传播的证据。每所机构感染儿童的中位数为2例（范围为2至18例），中位数发病率为22%（范围为3%至38%）。每所机构首例病例的中位数年龄为26个月（范围为12至59个月）。在儿童被暂时排除直至连续两次粪便培养结果为阴性的机构中，没有进一步传播的证据。
有症状的感染学龄前儿童 attended日托时，大肠杆菌O157:H7的人际传播很常见。由于粪便培养物中缺乏对该病原体的常规检测、许多地区缺乏公共卫生监测以及对感染儿童的随访不完整，美国未被识别的日托机构疫情可能相当严重。暂时排除所有儿童是该人群中的一种有效控制策略，但需要进一步调查以确定最佳干预措施。
