Navin T R, Juranek D D, Ford M, Minedew D J, Lippy E C, Pollard R A
Am J Epidemiol. 1985 Aug;122(2):269-75. doi: 10.1093/oxfordjournals.aje.a114098.
An outbreak of Giardia lamblia gastroenteritis occurred in Reno, Nevada, in 1982, during which 324 laboratory-confirmed infections were reported. During the outbreak, Reno was supplied in part by surface water that was chemically coagulated, settled, and chlorinated, but was not filtered. Giardia cysts were recovered from the water supply, and a beaver infected with Giardia was found in one of the reservoirs. A case-control study indicated that, during the outbreak but not afterwards, persons with giardiasis drank more municipal water than did controls. Corrective measures, which included removing the infected beaver and increasing the chlorine concentration, were followed by a rapid decrease in reports of giardiasis.
1982年，内华达州里诺市爆发了蓝氏贾第鞭毛虫肠胃炎疫情，期间报告了324例实验室确诊感染病例。疫情期间，里诺市部分供水来自经过化学混凝、沉淀和氯化处理但未经过滤的地表水。从供水系统中检测出了贾第虫囊肿，并且在其中一个水库中发现了一只感染贾第虫的海狸。一项病例对照研究表明，在疫情期间而非之后，患贾第虫病的人比对照组饮用了更多的市政供水。采取了包括移除受感染海狸和提高氯浓度在内的纠正措施后，贾第虫病报告病例迅速减少。
