MMA president Dr John Chew told FMT there were many different strains of the rotavirus which was spread through oral and faecal routes.
The Kedah Health Department has recorded 11 new cases of rotavirus infections in the state since last Friday. There were seven other recorded cases earlier.
The cases involved children and teenagers between the ages of one and 19. They sought treatment for diarrhoea and vomiting after visiting the Ulu Legong hot springs in Baling, Kedah.
“It is very difficult to check whether water in a pool, lake or waterfall has been contaminated with the virus until a person has been infected and they start showing symptoms,” he said.
Symptoms for rotavirus include fever, vomiting and diarrhoea that could lead to dehydration.
He said young children were usually more susceptible to rotavirus infections as their immune levels were lower than that of older children.
Chew said since the virus spread easily, parents should avoid taking young children to crowded pools or recreational waters including waterfalls and lakes as their immunity to fight the rotavirus was not yet fully developed.
“It is common for children to be re-infected because of the different strains but the subsequent infections are usually less severe.”
Chew said since the rotavirus spread through the faeces of those infected, parents were duty-bound to ensure their children who played in swimming pools or recreational waters, defecated in public toilets – or, if one was not available, in plastic bags – avoided contaminating the water that others also used.
He said vaccination was an option for children under six months of age, but cautioned that this was not a cheap alternative as it cost around RM300 at private clinics.
Previously, the health ministry said the rotavirus vaccine would be included in the National Immunisation Programme (NIP) if mortality rates due to the disease exceeded 10% for children aged five and below.
Last October, it was reported that the management of the water theme park in Bukit Merah Laketown Resort was forced to shut operations for 14 days so the pool could be thoroughly cleaned. The pool water had to be replaced after a number of rotavirus and acute gastroenteritis cases were traced back to the theme park.