LCQ15: Hand, foot and mouth disease

     Following is a question by the Dr Hon Helena Wong and a written reply by the Secretary for Food and Health, Professor Sophia Chan, in the Legislative Council today (November 13):
     It has been reported that earlier on, a primary school stated in a notice to the parents that some of its students had contracted the hand, foot and mouth disease (HFMD), and that the Centre for Health Protection (CHP) of the Department of Health had instructed that there was no need for students to wear masks because the disease was not transmitted by respiratory droplets. In response to media enquiries, CHP advised that while wearing masks was not the main measure for preventing the disease, it had not given the said instruction. Furthermore, CHP points out on its website that HFMD is mainly transmitted by contact with an infected person's nose or throat discharges, saliva, etc. In its guidelines distributed to schools, CHP classifies the mode of transmission for HFMD as "contact transmission" instead of "droplet transmission". However, a paediatrician has pointed out that the disease can be transmitted by respiratory droplets (saliva being a type of such droplets), and that wearing masks is one of the precautionary measures. Some members of the public find the relevant information on HFMD confusing. In this connection, will the Government inform this Council:
(1) whether CHP has gained an understanding from the aforesaid primary school on the reasons for the school stating in the notice that CHP had given the aforesaid instruction;
(2) whether CHP will discuss with the medical sector the ways for providing the public with clear guidelines on prevention of HFMD, including the effectiveness of wearing masks in preventing the transmission of HFMD; and
(3) whether CHP has conducted studies on the effectiveness of wearing masks in lowering the infection rate of HFMD; if so, of the outcome; if not, whether it will conduct such studies?

     Hand, foot and mouth disease (HFMD) is a common disease in children caused by enteroviruses such as coxsackieviruses and enterovirus 71. In Hong Kong, the usual peak season for HFMD is from May to July and a smaller peak may also occur from October to December. Having consulted the Department of Health (DH), reply to the question raised by the Dr Hon Helena Wong is as follows:

     On the mode of transmission of HFMD, unlike influenza viruses which mainly spread through droplets when infected persons cough, sneeze or talk, viruses that cause HFMD, despite their presence in droplets from infected persons, mainly spread by contact with an infected person's nose or throat discharges, saliva, fluid from vesicles or stool, or by touching contaminated objects. The incubation period of HFMD is about three to seven days. The disease is most contagious during the first week of the illness and the viruses can be found in stool for weeks. As there is no effective vaccine to prevent HFMD at present, good personal and environmental hygiene are the mainstay of prevention.

     Key measures for maintaining good personal hygiene are:

(1) perform hand hygiene frequently, especially before touching the mouth, nose or eyes, before eating or handling food, after touching blisters, and after using the toilet;

(2) wash hands with liquid soap and water, and rub for at least 20 seconds. Then rinse with water and dry with a disposable paper towel or hand dryer. If hand washing facilities are not available, or when hands are not visibly soiled, hand hygiene with 70 per cent to 80% per cent alcohol-based handrub is an effective alternative;

(3) cover mouth and nose with tissue paper when sneezing or coughing. Dispose of soiled tissue paper into a lidded rubbish bin, then wash hands thoroughly;

(4) use serving chopsticks and spoons at meal time. Do not share food and drinks with others;

(5) do not share towels and personal items with others;

(6) avoid close contact (such as kissing and hugging) with infected persons;

(7) refrain from work or attending school, and seek medical advice when feeling unwell; and

(8) exclude infected persons from handling food and from providing care to children, the elderly and immunocompromised people.

     Key measures for maintaining good environmental hygiene are:

(1) regularly clean and disinfect frequently touched surfaces such as furniture, toys and commonly shared items with 1:99 diluted household bleach (i.e. mixing one part of 5.25 per cent bleach with 99 parts of water), leave for 15 to 30 minutes, rinse with water and wipe dry. For metallic surface, disinfect with 70 per cent alcohol;

(2) use absorbent disposable towels to wipe away obvious contaminants such as respiratory secretions, vomitus or excreta, then disinfect the contaminated surface and neighbouring areas with 1:49 diluted household bleach (i.e. mixing one part of 5.25 per cent bleach with 49 parts of water), leave for 15 to 30 minutes, rinse with water and wipe dry. For metallic surface, disinfect with 70 per cent alcohol; and

(3) avoid group activities when HFMD outbreak occurs in schools or institutions. Meanwhile, schools and institutions should minimise staff movement and arrange for the same group of staff to take care of the same group of students or residents as far as possible.

     Generally speaking, upon notification of HFMD outbreaks from schools, the DH's Centre for Health Protection (CHP) will liaise with the schools concerned for epidemiological investigation and advise on necessary infection control measures. Such measures include intensified cleaning and disinfection of frequently touched surfaces (such as furniture, toys, shared items) and obvious contaminants (such as respiratory secretions, vomitus or excreta); avoiding group activities during the HFMD outbreak; and ensuring that staff and students perform hand hygiene frequently, refrain from attending school and seek medical advice when feeling unwell. The CHP had handled the HFMD outbreak of the primary school concerned according to the above established practice.

     It should be noted that while viruses that cause HFMD can be present in patients' droplets, droplet transmission is not the major mode of transmission. Hence, wearing masks is generally not regarded as a key measure to prevent HFMD. Nonetheless, under no circumstances would the CHP advise staff or students against wearing masks in schools where HFMD outbreaks occur. The CHP has all along advised schools to adopt a multi-pronged approach in implementing various preventive measures against infectious diseases, by following the Guidelines on Prevention of Communicable Diseases in Schools/Kindergartens/Kindergartens-cum-Child Care Centres/Child Care Centres, which include the proper use of masks, among other things. After the aforementioned primary school issued relevant notice to parents, the CHP had reiterated the health advice on prevention of HFMD to the school.
     Besides, when local activity of HFMD increases, the CHP will issue letters to all doctors and schools, urging them to stay vigilant against HFMD infection and providing information on a series of preventive and control measures, among other things. Moreover, the DH disseminates health messages on the prevention of communicable diseases and maintenance of personal and environmental hygiene, through various means, to the public, institutions, schools, healthcare personnel and stakeholders. The DH will continue to strengthen related publicity and risk communication work. As regards the effectiveness of wearing masks in reducing the infection rate of HFMD, the CHP will keep in view international studies and related recommendations.

Ends/Wednesday, November 13, 2019
Issued at HKT 15:53