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The following information is with regards to the recent article printed in the Daily Telegraph 13/3/98.

HEADLINE: Pool parasite attacks children, 300 swimmers ill.


There has been other Media coverage in relationship to this article. It appears that a number of PUBLIC Swimming pools in QLD, NSW and ACT have been shut down and empted having had the parasite Cryptosporidium detected in the pool water.


The first thing that must be considered is that the article relates specifically to Commercial pools and not semicommercial (hotel, motel, etc.) or private back yard swimming pools/spas. Secondly, not all the test results are back and it is not known whether any of the pools with positive results have contributed to illness, but as a precaution, owners have been responsible in deciding to close their pools for disinfection. The method used to eradicate the parasite was to drain, cleaned and refill. The pools will not be reopened until the health departments are confident there is no risk to bathers.


The purpose of this TIB is to provide sufficient information to our dealers so they may inturn, inform their pool or spa customers on What is Cryptosporidium?. Who’s at risk? How to treat should parasite be detected in pool water? But most importantly how to prevent any unnecessary risk of cross infection to bathers. Remember people buy pools and spas to enhance their life style not add to frustration .


What is Cryptosporidium?

As mentioned in the news paper article Cryptosporidium is a small parasite that is found in the faeces of infected humans or young animals. Humans are infected when they ingest oocysts that contaminates water, food, hands or other objects.


Who’s at Risk?

In persons with low immune systems, Cryptosporidium infection causes diarrhoea that is usually watery and lasts up to 1 to 2 weeks and is often accompanied by abdominal cramps, fatigue, nausea, vomiting and low-grade fever. People usually develop symptoms about 5 to 9 days after ingesting the oocysts. In persons with severely weakened immune systems Cryptosporidium can be chronic and severe. The watery diarrhoea can be prolonged and debilitating and may be fatal. Persons at risk of severe Cryptosporidium include persons with AIDS, persons who have cancer, organ or bone marrow transplants who are taking drugs that weaken the immune system and persons who are born with genetically weakened immune systems.



One of the comments made in the article is that Cryptosporidium is chlorine resistant. This is true where levels of sanitiser are allowed to drop below Australian Standards recommended levels. The only way to eliminate this parasite other than draining and cleaning is to run higher than normal levels of chlorine, 4 to 5 times the recommended amount for a number of days OR using ozone. However, if using ozone it is important that the water has sufficient contact time with the ozone to achieve maximum effect.



1. Maintain appropriate sanitiser levels in accordance with the Australian Standards AS3633.

2. Maintain appropriate hygiene standards. Shower off before bathing.

3. It would not be recommended to allow children who are not toilet trained to swim or bath in pool or spa water. However, should faecal matter end up in the pool or spa water the following procedures would be required.

a. Remove all faecal contaminants.

b. Oxidise pool or spa water with chlorine levels up to 10 times greater that normal chlorine residuals.

c. Backwash, clean filter thoroughly ( chemically clean).

d. Run sanitiser levels higher than normal for a number of days.

Note: It may be best in the case of a spa to simple drain clean spa shell and filtration media

thoroughly and refill.


Pool and spas were designed for people to enjoy to remove their worries and frustration’s NOT add to it. Therefore, if commonsense prevails and the pool or spa owner is on a good program to control and prevent cross infection there is really nothing to worry about.


The above information is supplied by Bio-Lab and represents its best interpretation of available technical information at the time of preparation. The sole purpose is to supply factual information to Bio-Lab customers. It is not to be taken out of context nor used as support for any other claim not made herein.