This page contains a Flash digital edition of a book.
POOL PLANT – CRYPTOSPORIDIUM


Cryptosporidium: The Parasite We All Want To Control In Pools


STA’S POOL PLANT EXPERT ROBBIE PHILLIPS TAKES A CLOSER LOOK AT CRYPTOSPORIDIUM AND HOW THROUGH EDUCATION, GOOD HYGIENE AND FILTRATION, OUTBREAKS OF THE PARASITE IN WET LEISURE FACILITIES CAN BE PREVENTED


C


ryptosporidium is a protozoan parasite that causes acute gastroenteritis, which can last up to two weeks but has been known


to last even longer. Illness can also result in chronic, long-term infection.


Cryptosporidium inhabits the human gut, where it thrives and multiplies. Part of its life cycle involves the formation of dormant ‘spores’ that act like a protective shell. These spores (known as Cryptosporidium oocysts) are the mechanism for the transmission from one human host to another. The oocysts are about 5 microns in diameter and are shed via stools in huge numbers (106


to 107 per gram stool).


Ingestion of fewer than 10 oocysts may be sufficient to cause infection. Additionally, Cryptosporidium oocysts are especially resistant to the chlorine and bromine disinfection in swimming pools, where they can survive for many days.


Patients can shed the Cryptosporidium oocysts for up to two weeks after the symptoms have ceased. This is why it is crucial that people with diarrhoea must not swim and why people with cryptosporidiosis must not swim for two weeks after symptoms have ceased. Cryptosporidiosis is a very unpleasant illness, which main symptoms are watery diarrhoea, abdominal pain, fever and vomiting. Cryptosporidiosis outbreaks are more frequently linked to learner/toddler pools than in main pools, which reflect the vulnerability of young children who could also be the


source of infection. The oocysts sink only very, very slowly and because children often drink the water near the surface, the parasite has ready transmission to the intestine to cause infection and continue its life cycle.


Similarly the introduction of interactive play features and young children defecating and drinking water from the sprays has presented other high risk factors. STA recommends that


babies and children should not wear normal nappies in pools and similar facilities, but a purpose-made costume with a purpose-made waterproof nappy should be worn. This aids the containment of solid stools and is referred to as the ‘double-nappy’ system, where a second protective swim nappy layer is used over a disposable or reusable swim nappy. However, even this double-nappy system does not fully contain loose, runny stools and specifically oocysts. Two thirds of cryptosporidiosis cases are among children, and mostly in the under-fives. With diarrhoea being more frequent within this age group and outbreaks more readily noticed, this group is the highest risk. Young children are also more susceptible to infection and a study by Dufour et al (2006) estimated that during a 45-minute swim a child would consume 37ml of water compared to an


adult, who would ingest about 16ml. Very young children were not included in this study and the presumption would be that they consume more water, putting them at even more risk of infection.


HIGHLY INFECTIOUS


Cryptosporidium is highly infectious and research indicates that it can survive in a swimming pool for over ten days (see table from the Centres of Disease Control & Prevention). Evidence also shows that cases of cryptosporidium peak in the spring and autumn, so it is essential that bathers and operators are educated about the risks that the organism poses.


ACT NOW BEFORE IT’S TOO LATE A swimming pool is often an underrated provision until things go wrong and they have to shut.


It is therefore essential that leisure / pool operators fully appreciate the consequences that a detected outbreak of Cryptosporidium can have: 1. Loss of reputation and users 2. Loss of income 3. Substantial remedial works 4. Effect on staff confidence 5. Illness or worse – fatalities of the immune compromised.


Source: Centres for Disease Control & Prevention (CDC) 42 June 2013 SPN


BEST DEFENCE We must keep Cryptosporidium out of the pool to prevent outbreaks, and the best defence is education, good hygiene and filtration. This can be summarised as follows:


www.swimmingpoolnews.co.uk


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74  |  Page 75  |  Page 76  |  Page 77  |  Page 78  |  Page 79  |  Page 80  |  Page 81  |  Page 82  |  Page 83  |  Page 84  |  Page 85  |  Page 86  |  Page 87  |  Page 88  |  Page 89  |  Page 90  |  Page 91  |  Page 92  |  Page 93  |  Page 94  |  Page 95  |  Page 96  |  Page 97  |  Page 98  |  Page 99  |  Page 100