Infections caught in public swimming pools

How many little horrors can lurk in our public swimming pools? Well lots of them and we are not talking about those kids who insist on splashing everyone. Some pathogenic bacteria, viruses and parasites are capable of living in water and infecting those swimming in public swimming pools.

So let’s start with parasites. The most common parasitic infections caught via swimming are Cryptosporidiosis and Giardiasis. Both of these cause gastrointestinal infections.

Cryptosporidium parvum, the cause of cryptosporidiosis, is resistant to chlorine and able to survive in chlorinated pools for up to a week. In immunocompetent people, it causes a self-limiting disease with watery diarrhea, nausea, abdominal pain and weight loss. In immunocompromised people with AIDS cryptosporidiosis is a life threaten tin condition.

A flagellated protozoan called Giardia lamblia causes Giardiasis. It causes a typical gastrointestinal upset with diarrhea, nausea and abdominal cramping. Persons become infected with Giardia lamblia by the ingestion of cysts. Swallowing as few as twenty-five cysts can cause infection. This parasite requires prolonged exposure to chlorine for its cysts to become inactive.

Another protozoan occasionally found in swimming pools is capable of causing a severe eye infection. Acanthamoeba species are not typically parasitic and normally live in the soil. They cause a keratitis (infection of the cornea) particularly in the wearers of contact lenses. Untreated, an infection with Acanthamoeba species causes blindness. Fortunately, this is a rare infection.

Chlorine inactivates most bacteria fairly rapidly but it still requires some time for the bacteria to be killed by the chlorine. Bacteria such as Escherichia coli and Shigella species (the cause of bacterial dysentery) are isolated from swimming pool water samples.

Pseudomonas aeruginosa lives in watery environments and so is frequently found in swimming pools. This bacterium causes ear infections. It also causes infections to abraded skin.

Swimming pool granuloma is a condition cause by the bacterium Mycobacterium marinum. Where cracks in the lining of swimming pools are not repaired, this bacterium is able to colonize such cracks. M. marinum infects abraded skin causing a granuloma. As swimming pools are well maintained this condition is now rarely seen. It can also be caught from working with aquariums and from swimming in sea water and most cases are from these sources.

Viruses like bacteria are killed by chlorine but they will take a short time before becoming noninfectious. Cases of viral gastroenteritis caused by swimming pool caught enteroviruses do occur occasionally.

The wart virus that causes verrucas has a long association with the swimming pool environment. It is not the swimming pool itself that allows the virus to be passed from one person to another but people walking around the pool area in bare feet catch the infection from contaminate surfaces.