KUALA LUMPUR: The recently reported outbreak of Rotavirus infections in two Perak districts has raised public concerns on waterborne diseases.
Last Feb 10, the media reported that two babies aged between two and 10 months succumbed to Rotavirus infection due to dehydration caused by severe diarrhoea.
The reports also said more than 2,200 people had taken ill from Rotavirus infection.
On Feb 11, the media reported that Health Minister Datuk Seri Liow Tiong Lai said the Rotavirus outbreak in Perak was under under control, as no new cases had been reported.
He said a special team from the Institute of Medical Research (IMR) and the ministry are currently looking into the water treatment plant distribution channels of the affected areas in Batang Padang and Hilir Perak.
As some viruses and bacteria are waterborne, what about people and their small children who frequent public recreational pools and water parks?There are several communicable diseases commonly associated with recreational swimming, wading and bathing pools.
Shower before entering pools
“Unfortunately it is impossible to prevent bacteria and viruses from entering pool water. In pools with a high number of visitors, including small children, the level of contaminants entering the water is especially high,” says Adam Abdullah, supervisor of a water park in the Klang Valley.
“We have advised sick adults and children not to enter the wading pool but many ignore this advice,” says Adam, adding that the management have put up notices that there is a risk of people contracting communicable and infectious diseases if they decide to use the pools.
“We have also advised visitors to shower first before entering the pools.
“I think many Malaysians ignore this advice about showering first before entering the pool. Visitors can carry contamination in the form of germs into the pool, which subsequently can infect other visitors.
“Some even have the audacity to jump into the pool wearing the clothes they wore when they arrived. They do not bother to change into suitable attire. It is difficult, even though there are notices telling them to do so.
“Don’t they realise that they may be carrying viruses and bacteria and will contaminate others, including young children who are in the pool, even though we use sanitisers in our pools?” says Adam.
Chlorine
He says water park operators use chlorine to decontaminate pools but chlorine breaks down very fast in the presence of high contamination, a high number of pool users, the sun’s ultraviolet rays, and heat.
Algae can grow in pool if there is urea in the water, according to Adam.
(Algae is a green, plant-like organism that grows in moist places and water).
“Urea salt gets into the water through unwashed sweat on the body and urine. That is why all swimmers must thoroughly wash themselves with soap before entering the pool.
“Pool management provides adequate bathrooms with showers as well as toilets for the visitors.
“Remember, if you do not wash well before entering the pool, you are spoiling its water quality. Never release urine while swimming in the pool. It is not only a nutrient for the algae to grow, it may also react with the chemicals used to disinfect the water in the swimming pool.
“Also, releasing urine in the pool is very unhygienic,” he says.
Recreational bathing poses risk
With these factors in mind, says Eirene, hotel manager at a resort, many swimming pool maintainers over-chlorinate the pool water in the hope that illness can be prevented.
This creates another dilemma. Chlorine, too, can cause health problems, and over-use should be avoided, say healthcare experts.
According to the medical experts, among the diseases that can result from infected pool water are gastroenteritis, dysentery, cholera, typhoid and hepatitis A.
Medical officer Dr Bernice Wong says an activity that is supposed to be fun and safe, recreational bathing, has now become a health risk.
“Recreational bathing includes swimming in pools, spas and hot springs, or wading and swimming in lakes, ponds, rivers, oceans or water parks.
“People become ill due to consumption of contaminated water, sometimes even when this water has been adequately chlorinated or sanitised,” she says.
Sodium hypochlorite
According to water park and hotel operators, sodium hypochlorite is most commonly used in swimming pools for water disinfection and oxidation.
Sodium hypochlorite has the advantage that microorganisms cannot build up any resistance to it.
Because of this, sodium hypochlorite is used both to oxidise pollutants, such as urine, sweat and cosmetics.
It is also used to remove pathogenic microorganisms. The required concentration of sodium hypochlorite depends on the concentrations of these pollutants.
Adam says the amount of organic pollution — such as sweat and urine — determines the required concentration of sodium hypochlorite used.
“If the water is filtered before sodium hypochlorite is applied, less sodium hypochlorite is needed,” he explains.
“Now you know the reason why pool management insists that you take a bath first, and must not enter the pool with sweat on your body or urinate in the pool,” adds Adam. — Bernama