Cryptosporidium: Unanticipated Risk Factors

Abstract

In April 1993, Milwaukee experienced the largest outbreak of waterborne Cryp- tosporidiosis in U.S. history. The official toll was “403,000 sickened, 44,000 doctor visits, 4,400 hospitalized, more than 100 deaths, 725,000 lost work or school days, $96 million in lost wages and medical expenses and $90 million for a new water pu- rification system” (Marchione, 2003, p. 01B). The outbreak caught the city off guard because MilwaukeeWaterWorks (MWW) officials and the Milwaukee Health De- partment had inadequate policies in place to monitor city water. Consequently, this case became an important learning opportunity for the Centers for Disease Control and Prevention (CDC), the Milwaukee Health Department, and city health officials nationally. This case provides an example of what happens when a city fails to adequately manage risks associated with its water treatment facility. Ultimately lessons learned from its crisis led to improvements for Milwaukee and the entire water treatment industry. This case proceeds as follows: (1) an overview of the case, including a time line, is given; (2) the case is then analyzed using the best practices in risk com- munication; and finally (3) practical implications for effective risk communication identified from this case are provided.