Giardia (genus name) and Cryptosporidium (genus name) are becoming the most widespread intestinal parasites, i.e., disease causing organisms, associated with waterborne disease. They are not the same organism, but different parasitic protozoans. The protozoans (Protista Kingdom) are unicellular animals (although some have some plant or fungal features) that, like cells in general, must be in liquid to be active. There are 4 major subgroups of protozoans, two of which are often combined. The ameba-like protozoans (called the Sarcodines) and the flagella-bearing protozoans (called Mastigotes) are often linked into one inclusive group (called Sarcomastigotes) because of some shared features. The cilia-bearing protozoans (called Ciliates) are about as complicated as single cells can be. The apicomplexans (which used to be called Sporozoans) tend to be tiny parasites, often living inside other cells, but are also pretty complicated. Many can survive drying by sealing themselves in protective coverings as cysts or oocysts, but they are not really doing much in those stages. (Source) Giardia is a mastigote (flagella-bearing protozoan) and Cryptosporidium is an apicomplexan.
These organisms are not bacteria or viruses, but protozoans with complex life cycles. Outside of the host, the organisms are in a cyst stage, which is much like a seed for a plant or microscopic egg. The size of the Giardia cyst is approximately 8 to 14 um; whereas, the Cryptosporidium oocysts are usually 4 to 6 microns in diameter. (Note: 1 micron = 0.001 mm = 0.00004 inches ), which is too small to see with the naked eye. The oocysts can survive six months or more in water, and are very resistant to disinfectants; whereas, cysts have been determined to survive up to 12 weeks in water, up to 7 weeks in soil. These organisms are responsible for over 100,000 causes of reported outbreaks of waterborne illness since 1979. These are not new organisms and in fact Van Leeuwenhoek first described Giardia cysts in 1681, but these organisms had not been identified as disease-causing agents until the last two decades.
Did You Know?
Giardiasis - Also known as Beaver Fever, Backpacker Disease, or Travelers Diarrhea
Upon ingestion, the acids in the stomach cause the cysts or oocysts to begin to ex-cyst ("like hatching an egg") and the organism begins to reproduce in the intestines. As few as 10 Giardia cysts have been shown to cause the disease giardiasis although it is not currently known what the minimum number of oocysts is to get the disease, cryptosporidiosis. This disease creates symptoms that mimic other gastrointestinal problems and the common symptoms are persistent diarrhea, weight loss, abdominal cramps, nausea, and dehydration. In general, the symptoms begin within a week after exposure and the acute symptoms can last for up to 2 weeks, but chronic symptoms can last for up to 2 months. With proper treatment and our natural immune system, the diseases are not deadly, but these diseases can be life-threatening to AIDS patients, small children, the elderly, or someone recovering from major surgery. Individuals can become exposed to these organisms through a number of routes, i.e., food-borne, waterborne, "hand to mouth transfer", and there may be an external host such as beavers, deer, dog, cats, cattle, and even rodents discharging cysts/oocysts into water supplies. With respect to a waterborne route, the exposure is typically associated with drinking from a water source that was untreated or ineffectively treated to remove the cyst or oocyst stage of the organism.
Waterborne: The drinking water supply becomes contaminated by malfunctioning on-lot wastewater disposal systems, improperly disposed sludge, improperly treated surface water, or groundwater sources under the direct influence of surface water. Groundwater is not a common route of contamination, but surface water can be a common route or wells that are improperly constructed or over-pumped can induce groundwater contamination.
Foodborne: Mother was changing the diapers of her infant and returned to canning products for the church picnic without thoroughly washing her hands and the individual purchasing the last batch of the canned items became sick. This is an example of how someone could become exposed to fecal material that contains the cysts. Similar stories could be told of exposure to cyst-contaminated soil or even pet hair.
This is a route of transmission if you engage in anal-oral sex. Overall, the most widespread route of transmission is through the consumption of contaminated or inadequately or improperly treated drinking water.
The EPA developed the surface water treatment rule as an attempt to create an engineering barrier between the source and the consumer. The rule requires the regulated water supplier to determine if the source of water is a "surface water source or a groundwater source under the direct influence of surface water". The regulations require that regulated sources be filtered and disinfected to a higher standard, set Maximum Contaminant Level Goals (MCLG) for Giardia, Cryptosporidium, viruses, and other agents, and required the implementation of watershed protection programs (Source). This standard does not apply to unregulated sources and many small non-community systems.
MCLG: Giardia - "Zero" (99.9% removal/inactivation) ; Cryptosporidium - "Zero", Viruses (enteric) - "Zero" (99.99% removal/inactivation), and Legionella -"Zero".
Giardia - the symptoms of an infection by Giardia typically appear within 3 to 25 days of exposure. The most common symptoms include: diarrhea, flatulence (a lot), abdominal pain, bloating, greasy stools, belching, nausea, stomach cramps, weight loss, fatigue, headaches, and upset stomach. (Source) Also, some individuals may be asymptomatic carriers, i.e., have the disease but show no evidence of symptoms. "Giardiasis infections usually last about six to eight weeks, but problems such as lactose intolerance can persist after the infection clears up." (Source)
Cryptosporidium - the symptoms of an infection by Cryptosporidium typically appear within 1 week of exposure, but the range is 2 to 10 days, and the common symptom include: very watery diarrhea, lack of appetite, weight loss, stomach cramps, pain, fever, vomiting, nausea, and dehydration. The most likely individuals impacted by this organism include: "children under two years of age, those who travel, work with animals, or those in close personal contact with someone who has this disease. People with weakened immune systems, such as people with HIV infection or those receiving chemotherapy, are more susceptible to the disease" (Source).
Getting your water quality tested for Giardia and Cryptosporidium is getting easier, but it is still expensive. You may want to conduct this testing if you experiencing any of the following:
Level 1 Testing is done with simple observations that an individual can make with their own senses such as sight, smell, and taste. These observations can be readily apparent or can be observed as they change over time. In addition, accessible related information about the home can also be used to narrow down the cause of your water issues.
You may suspect a problem with Giardia or Cryptosporidium in the following situations:
Level 2 Testing is Do-It-Yourself testing that can be done in your own home using a Testing Kit. After you’ve done Level 1 Testing, Level 2 Testing can confirm if your observations are correct. If your test results reveal the presence of a contaminant that is cause for concern, you can either proceed to determine the best treatment (see below) or continue to Level 3 Testing.
There are no Level 2 Do-It-Yourself tests for waterborne pathogens, but there are low cost tests to check the potability, i.e., drinkability, of your water, that test for total coliform bacteria and E. coli If you test your water and it is negative for Total Coliform and E. coli, it is less likely the water would be a source of a pathogen; it does not mean it is NOT a source. If it is positive for Total Coliform or E. coli, it means it is MORE likely a potential source, it does not mean it is!
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Level 3 Testing is done through an accredited Water Testing Laboratory. With Level 3 Testing, you can order a testing kit that is used to prepare your sample and submit it to the lab. By utilizing a lab, you have the assurance that a certified water expert had analyzed your water sample. If your test results reveal the presence of a contaminant that is cause for concern, you can either proceed to determine the best treatment options (see below) or continue to Level 4 Testing - Certified Testing.
A Level 4 Certified Test Test uses chain-of-custody with a water professional coming to your home to prepare the water sample and then works with an accredited laboratory in order to certify your test results. This type of testing not only gives you the highest level of assurance in the accuracy of your test results, but can also be used as a document in legal cases. For Baseline Testing, we recommend that you use Certified Testing.
There is certified testing for specific waterborne diseases, but this testing is expensive and typically requires laboratory or environmental professionals to collect water quality samples. If you suspect this contamination is related to a regulated activity, regulated by state or the federal government, we suggest documenting your experiences and contacting your local, state, or federal regulatory agency. When you do this testing, we strongly recommend testing for total coliform, E. coli, standard plate count, and other indicators that may be associated with the actual water source such as potential human, agricultural, or animal sources of contamination. If you need assistance, please feel free to contact the team.