The most common parasites found in water sources contaminated with human or animal feces are Cryptosporidium and Giardia intestinalis (also called Giardia lamblia or Giardia duodenalis).
Common Waterborne Parasites
These microscopic parasites can cause significant illness if ingested. Here's a breakdown:
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Cryptosporidium: This parasite causes cryptosporidiosis, an illness characterized by watery diarrhea, stomach cramps, nausea, and fever. Cryptosporidium is highly resistant to chlorine disinfection, making it a persistent threat in water systems.
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Giardia intestinalis: This parasite causes giardiasis, another diarrheal illness. Symptoms include gas, abdominal cramps, nausea, and dehydration. Giardia is more susceptible to chlorine than Cryptosporidium but can still survive in treated water if not properly filtered.
Other Parasites Potentially Found in Water
While Cryptosporidium and Giardia are the most frequently encountered, other parasites can also contaminate water sources:
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Entamoeba histolytica: This parasite causes amoebiasis (amoebic dysentery), a severe intestinal infection that can spread to other organs.
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Cyclospora cayetanensis: This parasite causes cyclosporiasis, leading to watery diarrhea, loss of appetite, weight loss, stomach cramps, bloating, increased gas, nausea, and fatigue.
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Toxoplasma gondii: While typically associated with cat feces and undercooked meat, Toxoplasma gondii can also contaminate water sources and cause toxoplasmosis.
Preventing Parasitic Infections from Water
To prevent infection from these waterborne parasites, consider the following measures:
- Boiling: Boiling water for one minute (three minutes at high altitudes) kills most parasites.
- Filtration: Using a water filter with a pore size of 1 micron or smaller can effectively remove Cryptosporidium and Giardia.
- Water Treatment: Municipal water treatment plants use a combination of filtration and disinfection to remove and kill parasites.
- Personal Hygiene: Washing hands frequently with soap and water, especially after using the toilet and before preparing food, can prevent the spread of parasitic infections.
