Cryptosporidium Outbreak, Research Paper Example

The 1993 Cryptosporidium Outbreak in the City of Milwaukee

In scientific terms, cryptosporidium is a protozoan parasite (i.e., microscopic) that was first discovered in 1907. Initially, this new type of protozoan was not seen as a threat to human life, but in 1976, the “first case of human cryptosporidiosis, a rare, opportunistic animal pathogen” was identified in a “three year-old girl from rural Tennessee who suffered severe gastroenteritis for two weeks” (Hannahs, “Cryptosporidium parvum: An Emerging Pathogen”). This single infection then led to a number of studies on the Cryptosporidium parvum parasite which revealed a close relationship between the parasite and HIV/AIDS in relation to persons with compromised immune systems. Other studies done in the early 1990’s revealed that Cryptosporidium parvum was spread through infected drinking water (Hannahs, “Cryptosporidium parvum: An Emerging Pathogen”), thus making this parasite a water-borne pathogen.

Some of the basic symptoms associated with Cryptosporidium parvum includes frequent watery diarrhea, nausea and vomiting, severe abdominal cramps, a low-grade fever, rapid weight loss because of a lack of appetite, and in some instances anorexia. As to its epidemiology, Cryptosporidium parvum has been reported on almost every continent, especially Africa and Asia, and occurs in all age groups. The mode of transmission  is mostly “fecal-oral, often through water contaminated by livestock mammal feces.” Those that are most likely to become infected with the parasite includes infants and young children, persons whose drinking water is unfiltered and untreated or who work on a farm with livestock, those who practice homosexual oral sex, health care workers, veterinarians, travelers to foreign countries in Africa and Asia, persons who live in dense urban areas and overcrowded cities, such as in India and China, and those who own infected pets (Hannahs, “Cryptosporidium parvum: An Emerging Pathogen”).

The most famous example of a Cryptosporidium parvum outbreak occurred in the city of Milwaukee, Wisconsin, in the early spring of 1993. According to Kirsten H. Ellis of the Infectious Disease News, this severe outbreak began when hospitals and schools in Milwaukee “reported staffing issues to the city’s Department of Public Health” regarding the number of people who had called in sick. Two of Milwaukee’s top newspapers reported on the outbreak but the cause for the outbreak remained unknown. Over the course of two weeks, some “403,000 people in Milwaukee reported sudden acute watery diarrhea,” one of the major symptoms of infection (“Cryptosporidium in Milwaukee’s Water Supply Caused Widespread Illness”).

After much research into the outbreak, the Wisconsin Department of Public Health discovered that it was caused by the Cryptosporidium parvum parasite which had contaminated the city’s water supply. As of 2014, the outbreak in Milwaukee continues to be “the largest epidemic of waterborne disease reported in U.S. history” (Ellis, “Cryptosporidium in Milwaukee’s Water Supply Caused Widespread Illness”).

Within three weeks of the outbreak, almost every person living in the city of Milwaukee was infected with the parasite. CDC medical epidemiologist Dr. William R. MacKenzie then realized that some of his HIV/AIDS patients were suffering from the same general symptoms as the people of Milwaukee. Since MacKenzie specialized in water-borne pathogens, he immediately contacted the Wisconsin and Milwaukee Departments  of Health and informed them that Cryptosporidium parvum parasite “could not be detected by standard tests of water quality and cannot be killed with chlorine at the concentrations used in routine water treatment” (Ellis, “Cryptosporidium in Milwaukee’s Water Supply Caused Widespread Illness”).

Once Milwaukee’s city officials had learned about what was happening, they made several bold attempts to prevent further infection, such as shutting down a large filtration plant on the south side of the city. However, it was soon leaked by the press that plant operators “had lost full control of the treatment process in late March” which allowed the parasite to pass through the filters. In typical style, plant operators and some city officials “paid no attention to the crude indicators of changing water quality” that would have indicated the presence of some type of contaminant in the water. When city officials finally announced that all citizens must boil their water before consuming it, the Cryptosporidium parvum parasite had been in circulation for more than two weeks, thus making other efforts to prevent more infection redundant water (Behn, “Milwaukee Marks 20 Years Since Cryptosporidium Outbreak”).

Over the course of several long weeks, the Cryptosporidium parvum parasite caused the deaths of seventy people in the Milwaukee area. Most of these (93%) were already infected with the HIV/AIDS virus and suffered from compromised immune systems which explains why the parasite was fatal for these individuals. The remaining 7% of fatalities were made up of cancer patients and young children (Behn, “Milwaukee Marks 20 Years Since Cryptosporidium Outbreak”).

Today, preventive measures against future Cryptosporidium parvum parasite outbreaks and infections in the water system of major cities like Milwaukee appear to have worked well. For instance, all city-based water filtration systems now have special filters and monitors that detect total particle counts in the water. Also, new pipelines have been installed to help transport water away from the point of contamination. There are also two foot thick coal filters and chlorine has been replaced with ozone which acts as  the “primary disinfectant because it can kill microorganisms” like the Cryptosporidium parvum parasite (Behn, “Milwaukee Marks 20 Years Since Cryptosporidium Outbreak”). Since these precautions were installed, there have been no serious reports of  Cryptosporidium parvum parasite infection in the water systems of the U.S.

Works Cited

Behn, Donald. “Milwaukee Marks 20 Years Since Cryptosporidium Outbreak.”2013 Web. Accessed 8 April 2014.

Ellis, Kirsten H. “Cryptosporidium in Milwaukee’s Water Supply Caused Widespread Illness.” 2007. Web. Accessed 8 April 2014.

Hannahs, Gregory. “Cryptosporidium parvum: An Emerging Pathogen.” 1996. Web. Accessed 8 April 2014.