How does Cryptosporidium affect public health?* Cryptosporidium cryptosporidium (krĭp'tōspərĭd`ēəm), genus of protozoans having at least four species; they are waterborne parasites that cause the disease cryptosporidiosis. is a microscopic parasite contained in an oocyst oocyst /oo·cyst/ (-sist) the encysted or encapsulated ookinete in the wall of a mosquito's stomach; also, the analogous stage in the development of any sporozoan. o·o·cyst n. that breaks open and releases sporozoites once it enters the gastrointestinal tract gastrointestinal tract n. The part of the digestive system consisting of the stomach, small intestine, and large intestine. Gastrointestinal tract . These sporozoites invade the GI tract lining. causing a disease known as Cryptosporidiosis Cryptosporidiosis Definition Cryptosporidiosis refers to infection by the sporeforming protozoan known as Cryptosporidia. Protozoa are a group of parasites that infect the human intestine, and include the better known Giardia. , the chief symptom of which is acute watery diarrhea. There is no known cure other than treatment of the symptoms. * One of the primary sources of Cryptosporidium is drinking water drinking water supply of water available to animals for drinking supplied via nipples, in troughs, dams, ponds and larger natural water sources; an insufficient supply leads to dehydration; it can be the source of infection, e.g. leptospirosis, salmonellosis, or of poisoning, e.g. or contact with recreational waters contaminated contaminated, v 1. made radioactive by the addition of small quantities of radioactive material. 2. made contaminated by adding infective or radiographic materials. 3. an infective surface or object. by domestic and wild animal feces or human wastewater. Contact with infected animals or individuals is another possible pathway. It can infiltrate drinking water systems from source water contaminated by sewer overflows, wastewater plants and agricultural operations, as well as treatment plant breakdowns. * Cryptosporidiosis more severely affects those with depressed immune systems, such as AIDS and cancer patients, the very young, or the elderly. However, in instances where drinking water supplies become contaminated, widespread effects may occur in the general population. How Are Water Systems Kept Free of Cryptosporidium? * Because of its ubiquity in animals, the presence of Cryptosporidium oocysts is widespread in surface water sources as well as in some groundwater sources. * Unfortunately, this parasite is resistant to the traditional disinfection disinfection, n the process of destroying pathogenic organisms or rendering them inert. disinfection, full oral cavity, n a procedure used to reduce active periodontal disease, usually completed within a certain short time frame. methods alone. Filtration in conjunction with ozonation and chlorine, plus chloramines, is generally effective in removing or destroying it if such treatment occurs before the water is released for distribution. * Testing in watershed areas can detect the presence of Cryptosporidium and alert water treatment authorities to take necessary preventive measures. Particle and turbidity turbidity /tur·bid·i·ty/ (ter-bid´i-te) cloudiness; disturbance of solids (sediment) in a solution, so that it is not clear.tur´bid Turbidity The cloudiness or lack of transparency of a solution. readings can be used to evaluate filtration. * If the water supply becomes contaminated, boil-water advisories are required to prevent or minimize infection among the population. How Is the Public Being Protected from Cryptosporidium Infection? * Current approaches in monitoring do not guarantee protection from Cryptosporidium in drinking water. Health professionals, water treatment specialists, environmental experts, and government regulators have been examining methods to improve the prevention, detection, and treatment of Cryptosporidium in water sources. Cooperative efforts among these entities will enhance their ability to contain future outbreaks of Cryptosporidium related illness. * Additional research is proceeding on the health effects of Cryptosporidium, which are still incompletely understood. * The Environmental Protection Agency Environmental Protection Agency (EPA), independent agency of the U.S. government, with headquarters in Washington, D.C. It was established in 1970 to reduce and control air and water pollution, noise pollution, and radiation and to ensure the safe handling and has proposed new regulations for water disinfectants and disinfectant by-products as well as for surface water treatment, in an attempt to improve monitoring, testing, and treatment for both chemical and microbial microbial pertaining to or emanating from a microbe. microbial digestion the breakdown of organic material, especially feedstuffs, by microbial organisms. contaminants. More research and regulatory flexibility is being sought to balance the relative risks between these two threats to drinking water supplies. * Drinking water suppliers are attempting to develop and implement the most effective detection and treatment methods for dealing with Cryptosporidium. Multi-barrier techniques, including source water protection, followed by filtration and disinfection in the treatment plant, plus a distribution system disinfectant residual, are considered the best approach. Reprinted with permission from Drinking Water & Health, Vol. 2, Issue 3, Spring 1995. |
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