Moorehead W P, Guasparini R, Donovan C A, Mathias R G, Cottle R, Baytalan G
South Okanagan Health Unit, Kelowna, BC.
Can J Public Health. 1990 Sep-Oct;81(5):358-62.
A giardiasis outbreak from a chlorinated, unfiltered surface water supply in Penticton, British Columbia (pop. 25,000) from June to August 1986 resulted in 362 laboratory-confirmed cases. A telephone survey estimated an attack rate of over 12%. A reservoir pond containing Giardia-infected beaver was implicated as the source. A case-control study with 65 cases did not find any significant associations. A retrospective case-finding survey of records from eight (out of 35) general physicians estimated that 1,500 physician visits occurred and produced an epidemic curve in close parallel with that from laboratory-confirmed and reported cases. Despite improvements on the reservoir, another outbreak occurred when this water source was reinstituted in October for several weeks, confirming our conclusion that it was the source of the first outbreak. Various options for reducing the risk of future outbreaks are being explored including full water treatment.
1986年6月至8月，加拿大不列颠哥伦比亚省彭蒂克顿市（人口2.5万）一个经过氯化处理但未经过滤的地表水源引发了贾第虫病疫情，导致362例经实验室确诊的病例。一项电话调查估计感染率超过12%。一个含有感染贾第虫的海狸的蓄水池被认为是传染源。一项针对65例病例的病例对照研究未发现任何显著关联。对35名全科医生中的8名医生记录进行的回顾性病例查找调查估计，有1500人次就医，绘制出的流行曲线与实验室确诊及报告病例的流行曲线非常相似。尽管蓄水池状况有所改善，但10月该水源重新启用几周后又发生了一次疫情，证实了我们关于其是首次疫情源头的结论。目前正在探索各种降低未来疫情风险的方案，包括全面的水处理。
