AskST: Are humidifiers really effective in preventing HFMD?

Reader Fang wrote in to point out that humidifiers are being marketed as effective and child-safe tools to kill Hand, Foot and Mouth disease (HFMD) and wanted to know: "Are these devices endorsed and recommended by the local authorities as effective and safe for use around young children? Is there any regulation for such devices and their claims of non-toxicity?

"In the light of the recent humidifier disinfectant scandal in Korea and the lack of disclosure of the ingredients used by the manufacturers, there is a need to provide more clarity on the safety and possible side effects of both short-term and long-term uses of such devices."

Senior Health Correspondent Salma Khalik answered.

Humidifiers are not regulated here. They are classed with other consumer electronics like fans and rice cookers.

However, any claims that they can prevent the spread of HFMD in a childcare setting are unlikely to be true. This is because the virus is not airborne, but spread through bodily fluids like saliva and urine.

Dr Leong Hoe Nam, an infectious diseases doctor in private practice, said: "The usage of humidifiers may reduce the transmission slightly but it is inconsequential. It might be effective if the humidifier is placed within close proximity."

However, it may not be sufficient to prevent transmission. "The key to prevention is to maintain good hand hygiene, avoid contact with fluid-filled blisters, and discourage sharing of drinks and toys especially among the young children."

The best way to prevent the spread of the disease is for parents to keep their sick children at home and away from other kids. When the child has recovered, he might still have the virus, but is very much less contagious.

There are currently four childcare centres with active clusters: Our Juniors Schoolhouse @ Choa Chu Kang, St Andrews Cathedral Child Development Centre, Nurture Stars @ Safra Toa Payoh, and MindChamps PreSchool @ City Square Mall.

The number of HFMD infections has topped 1,000 cases a week for the past two months.

There were 1,066 new infections in the week ending June 18.

A version of this article appeared in the print edition of The Straits Times on July 02, 2016, with the headline 'Are humidifiers really effective in preventing HFMD?'. Subscribe