OZONECARBON TECHNOLOGIES PTE LTD.
70 Anson Road, #26-03, Apex Tower, Singapore 079905
Phone:+65 6327 2490; DID: +65 6764 9667; Mobile: +65 9620 7794
Fax: +65 6327 2465
Email: pmmenon@ozonecarbon.com.sg
Website:http://ozonecarbon.com.sg
Hand Foot and Mouth Disease (HFMD) is caused primarily by the Coxsackie and Enterovirus 71. It is spread by direct contact with the nasal discharge, saliva, faeces and fluid from the rash of an infected person. Children below the age of 5 are more susceptible to this illness with the hands, feet and diaper area affected by rash with small blisters.
There is no specific treatment for the infection other than symptomatic relief of symptoms. Although usually a mild disease, it has been associated with fatalities involving the heart and nervous system.
The best way to control the disease in premises such as childcare centres and preschools is to isolate the infected children and follow good hygiene practices, including frequent hand washing, disinfecting the premises, toys, utensils and other items children normally share and use.
Here are some tips from the CDC (Centers for Disease Control and Prevention) in USA:
- Wash your hands with soap and clean running water for 20seconds.
- Wet your hands with clean running water and apply soap.
- Use warm water if available.
- Rub hands together to make a lather and scrub all hand surfaces.
- Continue rubbing hands for 20 seconds — the time it takes to sing “Happy Birthday” twice.
- Rinse hands well under running water.
- Dry hands usinga paper towel or air dryer.
- If possible, use your paper towel to turn off the faucet.
- Using an alcohol-based hand rub is a good alternative to hand washing if soap and water aren’t available. However, it should be noted that alcohol is not potent to viruses.
When to wash hands
Hand washing should be done before and after eating, participating in high risk activities where germs may be encountered (eg., toys, utensils, using a computer keyboard etc), before and after changing a diaper, after touching pets especially reptiles and snakes, after touching raw foods, and before food preparation. There are many opportunities for hand washing, the more you wash, the fewer germs you have along for the ride.
- Before preparing or eating food
- After going to the bathroom
- After changing diapers or cleaning up a child who has gone to the bathroom
- Before and after tending to someone who is sick
- After blowing your nose, coughing, or sneezing
- After handling an animal or animalwaste
- After handling garbage
- Before and after treating a cut or wound
It may be good to supplement the water being used to hand wash with some sort of oxidizing/ non oxidizing biocides. There are several disinfectants available, a knowledge of which will help in choosing the right system.
1. Chlorine
Almost all oxidizing disinfectants such as chlorine/ hypochlorite etc., has to be transported across the microorganism’s cell wall where it reacts with the nuclear reproductive mechanism or enzymes life giving reactions in the cell making it incapable of reproducing. In other words, inactivating the microorganism making it less virulent.
2. UV system
Water may be passed through a germicidal UV system with adequate dosage and contact time to inactivate the microbes in water. The killing mechanism of the microbes is by UV rays’ ability to alter the DNA of the cell making it unable to reproduce/ inactivating the microbe. The disadvantage of this system is it does not leave a residual in the water for hand washing.
3. Ozone system
When properly applied, ozone is an attractive alternative due to its strong biocidal action against most microorganisms. A separate discussion on the use of ozone for disinfection is available on the website of Society of Environmental Health, Singapore.
Ozonating the water at the hand washing area and the rest rooms may provide an added protection in the fight against HFMD. [Ref: Midori Matsumoto, Tetsusuke Yokomi and Yutaka Shimada (Japan) “The Evaluation of Ozonized Water Hand – Washer for Medical Applications”,
13th. Ozone World Congress, Kyoto, Japan October 1997.]
The water can also be used to disinfect compatible surfaces in premises such as childcare centre. The safety measures must however be put in place to ensure that the level of ozone in air within the premises are kept well below the recommended limit of 0.05 ppm.
The viricidal effect of ozone develops through the destruction of membrane polypeptide chains that can lead to inability of viruses to fasten onto the target cells and to break down one thread of RNA into two parts thus destroying the basis for reproductive reaction. The capsulated viruses are more sensitive to ozone than the not-capsulated ones. It can be explained by the fact that the capsule contains many lipids, which easily react with ozone.
The mechanism of inactivation of virus can be explained by the following aspects:
- partial destruction of virus membrane and loss of its properties;
- inactivation of reverse transcriptase ferment that inhibits the process of transcription and translation of virus proteins and accordingly virus reproduction; and
- inability of virus to join with receptors of target cells.
Micro organisms particularly bacteria and viruses may develop an immunity to chemicals when used over a prolonged period of time, because of which biocides needs to be changed/rotated for effective control of microorganisms. There is no microorganism that is known to have developed a resistance to ozone till date; thereby eliminating the need to rotate biocides.
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