Water parasites: Cryptosporidium and Giardia, main causes of disease

It is found around the world, Cryptosporidium parvum (often simply called "crypto") and Giardia Lamblia ("Giardia") are current protozoa parasites which are two of the main causes of water diseases.
What is a protozoa?
Protozoa are unicellular microscopic organisms which are often parasitic, but can also live outside a host. Centers for Disease Control and Prevention notes that protozoa is "capable of multiplying in humans, which contributes to their survival and also allows serious infections to develop from a single organism". 1
What is a parasite?
"Parasite" is a general term which designates any organization that survives at the expense of its host. The CDC defines parasites as "an organization that lives on or in a host organization and feeds on or at the expense of its host. There are three major classes of parasites that can cause diseases in humans: protozoa, helminths and ectoparasites ”. 2
What are cryptosporidiosis and giardiase, and how do they spread?
Cryptosporidiosis and giardiase are two common gastrointestinal diseases caused by the ingestion of water contaminated by cryptosporidium or giardia. The parasites attach to the intestines of humans and animals, and are then transmitted in the environment through food or contact from person to person with excrement of humans or infected animals.
Difficult to eradicate
Cryptosporidium and Giardia are protected by chlorine -resistant external envelopes (oocysts and cysts, respectively) which allow parasites to live long periods outside their original host. Giardia cysts can survive several months in cold water 3, while cryptosporidium oocysts can survive for months in the ground in fresh and dark conditions and up to a year in low turbidity water. 4
Dispute easily
The figures are alarming: millions of oocysts and infectious cysts can be excreted in a single saddle, 5 but it is enough to swallow a small amount of water (as little as ten giardia cysts) 6 to infect a human. 7, 8 Thus, it is easy to understand why a contagious person suffering from diarrhea, a fleeing layer or a "intestinal accident" too frequent in a swimming pool, a spa or a small lake can present such a potential danger for health.
In addition to water as a source of transmission, it is important to note that food, earth, door handles, taps, toys or anything that is commonly shared or touched can also be contaminated. The ease with which these organisms can spread shows why it is so important to observe hygiene practices this summer, especially when handling food during outdoor celebrations and picnics, sharing phones And cameras, or even after outings in the toilet.
Number of cases reported
In 2012, there were 15,223 cases reported by Giardiase 9 and 8,008 cases of cryptosporidiosis. ten
Contact sources
Water is the most common mode of transmission. The parasites that cause cryptosporidiosis and giardiase can be found in almost all water sources, in particular:
Streams
some lakes
Pool
Whirlpool
Well 11
Is the public supply of water also vulnerable?
Even if raw water like lakes and streams is a major source of contamination, public water supplies are not immune to these parasites. Tap water can also be assigned. 12
According to the Ohio State University:
These parasites are not effectively controlled by chloration or other disinfectants. The chlorine used to kill bacteria in municipal water is not added to sufficient concentration or for sufficient duration to kill Giardia, Crypto and Cyclospora resistant to chlorine. Water filtration is common practice to control these parasites; Therefore, municipal drinking water programs are essential for protection. When municipal water is not available, boiling for at least 1 minute is an effective method for controlling these parasites in the water supply. 13
The Saskatchewan Note water safety agency:
These two parasites [Cryptosporidium and Giardia] are in the water of lakes and streams, and in certain sources of groundwater under the direct influence of surface water. Communities that obtain their drinking water from these surface water sources and do not treat their water properly can introduce parasites into their water supply system. These organisms are both very resistant to chlorine and other disinfectants used to kill bacteria and viruses in drinking water. In addition, Cryptosporidium and Giardia exist in the form of oocysts (cysts) or spores in the environment and are small enough to pass certain types of filters used in the treatment of conventional water. 14
Have there been notable and generalized epidemics?
Milwaukee, April 1993
The largest water epidemic in history occurred in 1993. It is estimated that 403,000 inhabitants of Milwaukee suffered from aqueous diarrhea due to the cryptosporidium oocysts found in the public water supply network of the city . Four thousands were hospitalized and more than 100 died. 15 One of the city's water treatment factories has been temporarily closed, but when the water boiling was announced, the pathogen was in the aqueduct network the city for more than two weeks. 16
The city of Milwaukee has since spent more than $ 200 million to modernize the city's treatment and distribution system. Turbidity (or nebulosity, indicator of the concentration of particles suspended in water) is now permanently measured and particle meters have been installed on the city's water filters. 17
The 1993 crisis demonstrated the need for greater awareness and understanding of cryptosporidium as risk to public health. Other identified lessons and needs included the analysis of the source and finished water for cryptosporidium, carrying out environmental studies and the important role that the media could play in the communication of important public health messages during the epidemic. 18
What are the symptoms and health effects of cryptosporidiosis and giardiase?
Looking like what you would call a serious case of food poisoning or a nasty "belly bug", both diseases have very similar symptoms, which may include:
Fate or aqueous diarrhea
Stomach cramps or pain
Lack of appetite
Weightloss
Bloating
Nausea and vomiting
Slight fever
Fatigue
Flatulence
Headache 19
Even if the symptoms are fundamentally the same, the period of time between the initial ingestion of the parasite and the symptoms manifesting is slightly different between the two diseases:
Symptoms of cryptosporidiosis may appear in the week following the infection and last up to two weeks, although they can come and go sporadically up to a month 20. There is no specific treatment for cryptosporidiosis, but drugs are available to help treat symptoms 21.
Symptoms of Giardiase can take a little more time to appear (up to three weeks) and can persist from two to six weeks, or even longer 22. Treatments are available for the Giardiase. 23
Some people host parasites but have no effect. Most cases disappear, but if you think you have contracted cryptosporidiosis or giardiase, it is always a good idea to ask for the advice and care of your health or professional of your choice.
Who most at risk of serious or serious cases of cryptosporidiosis or giardiase?
Again, many people infected with these two parasites will not notice any symptoms or will not feel sick. However, Saskatchewan Water Security Agency notes that certain groups such as pregnant children and women are more likely to develop a more serious illness. 24
People at risk of serious illness after being infected include:
People with AIDS
People with cancer
Patients transplanted with organs or bone marrow taking medication to remove the immune system
People born with a weakened immune system 25
Are cases more frequent at certain times of the year?
The cases reported are generally the highest during the hot months, when more people are exposed to parasites while enjoying water for outdoor recreational purposes. In 2011-2012, the CDC reported a peak in the appearance of the Giardiase from the beginning of summer to early fall. 26 During this same period, the appearance of symptoms of cryptosporidiosis was multiplied by 4.4 at the end of the summer. 27
How can I reduce my risk of being infected?
Ohio State University suggests doing the following to reduce your chances of suffering from the effects of giardiase and cryptosporidiosis:
OUTSIDE
Wash your hands with warm water and soap before eating or drinking.
When swimming in a lake, a river or a stream, try not to swallow the water.
Drink water from sources such as municipal water as far as possible.
If the treated water is not available, boil the water for at least 1 minute before drinking it. 25
AT HOME
Wash your hands with warm water and soap before eating or drinking.
Wash all the raw fruits and vegetables under running water of a treated source.
When you drink milk and juice, only use pasteurized products.
Use a vegetable brush to rub the outside of fruits and vegetables.
Be aware of public boiling alerts and follow the recommendations. 28
Public swimming pools and aquatic parks
In addition, for those whose idea of ​​"living the harsh" on vacation involves afternoon of idleness at the pool of their hotel, the CDC notes that a third of the epidemics of recreational water-processed diseases treated Between 2000 and 2014 occurred in hotel pools or whirlpools according to a report published in the weekly CDC report on morbidity and mortality.
Therefore, the CDC suggests taking the following precautions:
Do not swim and let your children swim if they have diarrhea. If Crypto is the cause of diarrhea, wait 2 weeks after stopping diarrhea to swim.
Check the inspection scores of swimming pools, whirlpools and aquatic play areas.
Before entering the water, use a test strip of your local retailer or a pool supplies store to check whether the pH and the bromine or the free chlorine of the water are correct.
Do not swallow the water.
Take the children to the toilet every hour and change the layers in a changing area and far from the water. 29
Your best defense is a final barrier system
As you can see, cryptosporidium and giardia are literally everywhere and present a real problem not only for raw water sources, but also for modern water supply systems. Since cryptosporidium and giardia resist chlorine and boiling water requires a lot of time and work (not to mention the supply of small amounts of water at a time), your best defense is to set up a final barrier system to purify your drinking water daily. base.
When selecting a system, inspect the test results with regard to parasites such as Giardia and Cryptosporidium. You will find below information on the Black Berkey ® purification elements.
Results of cryptoporidium reduction tests and Giardia reduction of the Black Berkey ® purification element
Drink with confidence: independent laboratory tests show that our elements are extremely effective in eliminating these parasitic contaminants. Indeed, no cyst has been detected in the effluent of the system tested for the two contaminants. This is important given that the consumption of only 10 giardia cysts can cause an infection. 30
Cryptosporidium
The minimum standard of elimination or inactivation of the Environmental Protection Agency in the United States for Cryptosporidium is 99 %, a reduction of 2 log. Black Berkey ® purification elements exceed the detectable laboratory limits, eliminating cryptosporidium at more than 99.997% (Log 4.6). It is more than double the EPA standard, by log 2.6.