Epidemiology and Infection · 2000 · 23 citations · 26 references
Public HealthCommunity HealthInfectious DiseasesEpidemiologic MethodsEpidemiologyOutbreak InvestigationDrinking Water SafetyOccupational Disease SurveillanceWater PollutionWater QualityWaterborne Outbreak InvestigationWaterborne ZoonosesCase-control Study DesignCohort Study InvestigationContaminated Water ExposureContaminated Water TransmissionInfection Risk FactorsWater Source ContaminationWaterborne ContaminationWaterborne Disease Epidemiology
In early 1992 we identified an outbreak of cryptosporidiosis in Oregon and sought to identify and control its source. We used a series of studies to identify risk factors for illness: (i) a case-control study among employees of a long-term-care facility (LTCF); (ii) a matched case-control study of the general community; (iii) a cohort study of wedding attendees; and (iv) a cross-sectional survey of the general community. Drinking Talent water was associated with illness in the LTCF (OR = 22.7, 95 % CI = 2.7-1009.0), and in the community (matched OR = 9.5, 95% CI 2.3-84.1). Drinking Talent water was associated with illness only among non-Talent residents who attended the wedding (P < 0.001) and in the community (RR = 6.5, 95 % CI 3.3-12.9). The outbreak was caused by contaminated municipal water from Talent in the absence of a discernible outbreak among Talent residents, suggesting persons exposed to contaminated water may develop immunity to cryptosporidiosis.
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