Adelaide Now reports that 28 people carrying cryptosporidium may have infected public pools, but South Australia Health has issued no public warning.

Between January and March, SA Health was notified of 28 cases of cryptosporidium where the person reported swimming at a public pool.

SA Health asked seven swimming centres across the metropolitan area to decontaminate their pools to prevent transmission of the infection.

The Advertiser was alerted to the situation when it obtained a copy of a text message sent to members of the Adelaide Aquatic Centre advising them the pool would be closed for super-chlorination.

Adelaide City Council confirmed the Aquatic Centre was aware an infected person had used the pool.

An SA Health spokesman said, "This is within the normal levels we would expect to see – there has certainly been no spike. If there were large numbers then we would issue a public alert.

"SA Health emphasises the importance of observing hand hygiene and people with diarrhoea not sharing baths or swimming in public pools for 14 days after their symptoms have stopped."