Related Experiment Video
Updated: Jul 30, 2026

EPA Method 1615. Measurement of Enterovirus and Norovirus Occurrence in Water by Culture and RT-qPCR. Part III. Virus Detection by RT-qPCR
Published on: January 16, 2016
Possible information bias in a waterborne outbreak investigation
1Gunther F. Craun & Associates, 101 West Frederick Street, Suite 205, Staunton, VA 24401, USA.
Abstract:
Although an investigation of a cryptosporidiosis outbreak in 1994 in Clark County, Nevada, concluded that illness was associated with consumption of municipal water, no water treatment deficiencies or breakdowns and no water quality changes were discovered during the investigation. We evaluated the strength of the evidence for waterborne transmission and conducted a sensitivity analysis to define the limitations of the epidemiological data. Our analyses suggest a spurious inference of waterborne transmission might be due to differential misclassification bias. If exposure and disease status were incorrectly classified for a relatively small number of study participants, findings of the investigation would be interpreted differently. We offer this example to illustrate the importance of assessing the stability of a relative risk estimate and effect of possible biases during an outbreak investigation.
More Related Videos
Related Concept Videos
Bias
In statistics, a sampling bias is created when a sample is collected from a population, and some members of the population are not as likely to be chosen as others (remember, each member...
Bias in Epidemiological Studies
Steps in Outbreak Investigation
Sources of Food Contamination
Investigation of Disease Outbreaks
Cholera

