What is Cryptosporidium?

Cathal Walsh
Environmental Blogger
Thursday, 18th April 2019
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scientist looking into microscope over petri dish

Cryptosporidium lives in the intestine of infected humans or animals. Millions of parasites can be released in a bowel movement from an infected human or animal. It is therefore found in soil, food, water, or surfaces that have been contaminated with human or animal faeces.

The parasite of cryptosporidium is protected by a large outer shell which both makes in tolerant to chlorine disinfection and allows it to live outside the body for extended periods of time.  The parasite can spread in several different ways; however recreational water and drinking water are the most common ways of spreading.

Cryptosporidium is transmitted to humans and animals via the faecal oral route. 

The symptoms of cryptosporidiosis appear between 1 and 12 days after infection and are mostly diarrhoea and stomach cramp. Symptoms of nausea, vomiting and weakness can also occur. These symptoms can go on to last days or even weeks so this is most definitely an ailment one would seek to avoid.

There are several ways however one can prevent catching cryptosporidiosis themselves or transferring it to others:

  • Wash your hands regularly
  • Boil your water during outbreaks
  • Avoid touching farm animals
  • Avoid touching the faeces of pets
  • Be careful when swimming in rivers, pools and lakes, and be careful not to swallow any water while swimming
  • Wash and cook your food carefully


An important thing to note is that testing for cryptosporidium can often be quite expensive and rigorous, but there is a useful way around it sometimes. Given that cryptosporidium comes from faecal matter the vast majority of there will be other forms of bacteria there, namely E-Coli. In nearly all cases where you find cryptosporidium there will be large amounts of E-Coli present as well. There is no smoke without fire here. If you carry out a test for E-Coli and find high levels there then treat the water as being infected with cryptosporidium

When boiling water for consumption in these cases be sure to bring the water to a proper boil for at least one minute in order to ensure its safety. This is because cryptosporidium is a tough bacterium and can survive temperatures as high as 70 degrees Celsius.


If you suspect your water may be infected with either cryptosporidium or E-Coli do not take any chances, start treating your water as it is infected and boiling it etc. After that, be sure to get your water tested for bacteria and other impurities from an accredited water tester.

 Follow the link for an advanced bacteria test https://www.h2olabcheck.com/product/advanced-bacteria-test

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