Ihekweazu C, Barlow M, Roberts S, Christensen H, Guttridge B, Lewis D, Paynter S
Health Protection Agency, South West, United Kingdom.
Euro Surveill. 2006;11(4):128-30.
In August 2004 seven cases of Escherichia coli O157 infection were identified in children on holiday in Cornwall, southwest England, all of whom had stayed at different sites in the area. Isolates from all seven cases were confirmed as E. coli serogroup O157 phage type 21/28. We carried out a case-control study among holidaymakers who visited the beach. A standardised questionnaire was administered by telephone to parents. They were asked where on the beach the children had played, whether they had had contact with the stream that flowed across the beach, and about their use of food outlets and sources of food eaten. Cases were more likely to have played in the stream than controls (OR [1.72- undefined]). The time spent in the stream by cases was twice spent there by controls. Cases and controls were equally exposed to other suspected risk factors. PFGE profiles for all the cases were indistinguishable. Increased numbers of coliforms were found in the stream prior to the outbreak. Cattle were found grazing upstream. We suggest that the vehicle of infection for an outbreak of acute gastrointestinal illness caused by E. coli O157 was a contaminated freshwater stream flowing across a seaside beach. The onset dates were consistent with a point source. Heavy rainfall in the days preceding the outbreak might have lead to faeces from the cattle potentially contaminated by E. coli O157 contaminating the stream, thereby leading to the outbreak. Control measures included fencing off the part of the stream in which children played, and putting up warning signs around the beach.
2004年8月，在英格兰西南部康沃尔郡度假的儿童中发现了7例大肠杆菌O157感染病例，他们都住在该地区的不同地点。所有7例病例的分离株均被确认为大肠杆菌O157血清型21/28。我们对到访该海滩的度假者进行了一项病例对照研究。通过电话向家长发放了标准化问卷。询问他们孩子在海滩的哪个位置玩耍、是否接触过流经海滩的溪流，以及他们对食品摊点的使用情况和所食用食物的来源。病例比对照更有可能在溪流中玩耍（比值比[1.72 - 未定义]）。病例在溪流中停留的时间是对照的两倍。病例和对照接触其他可疑危险因素的情况相同。所有病例的脉冲场凝胶电泳图谱无法区分。疫情爆发前，溪流中发现的大肠菌群数量增加。发现有牛在上游放牧。我们认为，由大肠杆菌O157引起的急性胃肠道疾病爆发的感染源是一条流经海滨沙滩的受污染淡水溪流。发病日期与点源一致。疫情爆发前几天的暴雨可能导致潜在被大肠杆菌O157污染的牛粪污染了溪流，从而引发了疫情。控制措施包括将孩子们玩耍的那段溪流围起来，并在海滩周围设置警示标志。
