Waterborne Pathogen: Cryptosporidium



Milwaukee, Wisconsin suffered the largest waterborne disease outbreak in U.S. history - 100 people died and 403,000 were sickened. When people started complaining about the odor and taste of their tap water, calls began flooding the Milwaukee Health Department. The water treatment plants had just passed inspection and tests for bacteria and viruses came up blank. Was sewage contaminating the public water supply? And if so, where was it coming from?

TMBA was asked to recreate animations that highlighted the findings of the CDC and EPA investigations. The animations aired on an episode of "Extreme Evidence" on tru TV.

Cryptosporidiosis, also known as crypto, is a parasitic disease caused by Cryptosporidium, a protozoan parasite in the phylum Apicomplexa. It affects the intestines of mammals and is typically an acute short-term infection. It is spread through the fecal-oral route, often through contaminated water.

The largest US waterborne disease outbreak occurred in Milwaukee, Wis., causing illness in more than 400,000 people. The etiological agent responsible for most cases was Cryptosporidium.

Milwaukee was served by two water treatment plants that used raw water from Lake Michigan. Before the outbreak, severe spring storms caused the lake's turbidity and bacterial counts to rise dramatically.

During the outbreak, effluent produced by one plant had a turbidity approaching 2.5 ntu, a high reading that indicated an increase in particulates passing through the plant. The increase may have also meant an increase in passage of Cryptosporidium oocysts. (http://cat.inist.fr/?aModele=afficheN&cpsidt=3201402)


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