Cryptosporidium
Cryptosporidium : From Water Technology Magazine,Volume 31, Issue 3 - March 2008
Species:
Notable outbreaks:
Water treatment methods (reduction or removal):
Sources: US Environmental Protection Agency (EPA), US Centers for Disease Control and Prevention, Water Quality Association, NSF International, US Department of Agriculture.
- Name: Cryptosporidium is a group of microorganisms containing a number of species, a few of which harm humans with the disease cryptosporidiosis. One common harmful species is Cryptosporidium parvum. Nickname: “Crypto.”
- Form: Single-celled protozoan and parasite that lives in human or animal intestines. Excreted in feces in the form of a dormant but hardy, thick-walled oocyst (“O-o-sist”), or fertilized egg. When ingested, it emerges from the oocyst and infects the intestine lining.
- Size: Oocyst is 3 to 5 microns in diameter.
- Other:
- Found in every region of the Earth in water, soil, food.
- Not eliminated by typical disinfectant chemicals (such as chlorine bleach). Killed at temperatures above 160°F (71°C) or by desiccation (extreme drying).
Notable outbreaks:
- 1987, Carrollton, GA: 13,000 people become ill in first report of its spread through a public water system that had been following state and federal drinking water standards in force at the time.
- 1993, Milwaukee, WI: 400,000 people become ill, again from municipal drinking water. May have caused over 100 deaths.
- Symptoms: Diarrhea, abdominal cramps, nausea, low-grade fever, dehydration, weight loss. Symptoms appear within two to 10 days after infection, rarely last more than two weeks.
- Infection routes: Ingesting anything that has come into contact with feces; swallowing pool, natural or tap water containing oocyst; touching the mouth with contaminated hands (changing diapers, handling infected animal, caring for infected person).
- Effects: No symptoms for some. Others with healthy immune systems have symptoms for one or two weeks. Symptoms can recur. Severe illness in those with weaker immune systems.
Water treatment methods (reduction or removal):
- Carbon adsorption
- Reverse osmosis, nanofiltration, ultrafiltration (or filtration with absolute rating of 1 micron).
- Ultraviolet
- Ozonation
- Distillation.
- Standard 53 — Drinking Water Treatment Units — Health Effects
- Standard 55 (Class A) — Ultraviolet Microbio-logical Water Treatment Systems
- Standard 58 — Reverse Osmosis Drinking Water Treatment Systems
Sources: US Environmental Protection Agency (EPA), US Centers for Disease Control and Prevention, Water Quality Association, NSF International, US Department of Agriculture.