It was just two weeks ago that the Independent and other sources informed the public that the Aquatic Center and the YMCA swimming pools were to be closed for a few days, and all potential users of these facilities who experienced diarrheal illnesses were advised to avoid using the pools for a period of two weeks.
Appropriate pool treatments were put in place to prevent spread of the illness. The Minnesota Department of Health was contacted to advise and give direction to the operators of these facilities and the public. A significant public health incident was avoided by these preventive actions.
The organism that presented such a potentially harmful threat to the public and caused summer swimming to be halted for a time is a recently (1976) recognized protozoan intestinal parasite called Cryptosporidium which causes the illness called Cryptosporidiosis. This parasitic, microscopic one-celled animal is associated with water sources and fomites such as food, soil, and surfaces contaminated by fecal matter from infected humans or other animals. Its method of transmission is the ingestion of oocysts from infected human waste by susceptible individuals, especially immunocompromized people such as young children, the elderly, and those individuals with rheumatic or kidney diseases or infections such as AIDS. The illness caused by "Crypto" is generally a self-limited non-specific diarrheal disease lasting about two weeks in a mild form. No specific treatment is usually necessary although adequate hydration should be maintained. A more complete and detailed information sheet from the Minnesota Department of Health is available at the YMCA desk and on the MDH website: www.health.state.mn.us . Every swimmer and family should review this important educational tool.
Although in many instances Cryptosporidiosis is a mild self-limited disease, previously epidemics have occurred. In 1987, a town in Georgia in the USA saw 13,000 people clinically affected. The city of Milwaukee, Wis., had a contaminated water supply in 1993 which gave rise to an epidemic of 400,000 clinical cases; 4,400 patients were hospitalized, and 60 died. Since this disease is often water-borne, both drinking water and recreational water sources such as lakes, pools, water parks and slides are now recognized as frequent sources of infections.
Episodes such as we experienced in Marshall provide interesting medical and public health "detective" or investigational stories for the reading public. A famous collection of such tales of public health intrigue from 1944-84 has been written by a journalist from The New Yorker Magazine.
Berton Rouech wrote his first story about an epidemic of ill men who turned blue in 1944, and he concluded his career by writing about an apparent epidemic of non-infectious disease near Marshall in 1984. His book, Eleven Blue Men and Other Stories is a classic in the fields of public health, true crime, and the mystery and detective fiction genre.