An integrated risk model of a drinking-water-borne cryptosporidiosis outbreak

A dynamic risk model is developed to track the occurrence and evolution of a drinking-waterborne cryptosporidiosis outbreak. The model characterizes a nd integrates the various environmental, medical, institutional, and behavi oral factors that determine outbreak development and outcome. These include contaminant delivery and detection, water treatment efficiency, the timing of interventions, and the choices that people make when confronted with a known or suspected risk. The model is used to evaluate the efficacy of alte rnative strategies for improving risk management during an outbreak, and to identify priorities for improvements in the public health system. Modeling results indicate that the greatest opportunity for curtailing a large outb reak is realized by minimizing delays in identifying and correcting a drink ing-water problem. If these delays cannot be reduced, then the effectivenes s of risk communication in preemptively reaching and persuading target popu lations to avoid exposure becomes important.