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Following is a question by the Hon James To and a written reply by the Secretary for Food and Health, Dr Ko Wing-man, in the Legislative Council today (March 18):
Question:
The outbreak of influenza in the current winter influenza season is more severe than that in previous years, with quite a number of people with weaker immunity, such as children and the elderly, having been infected. It is learnt that influenza viruses spread more easily in places with poor ventilation (such as public transport and shopping malls with faulty exhaust systems). In this connection, will the Government inform this Council:
(1) of the statistics on people infected with influenza in each of the summer and winter influenza seasons in the past three years, with a breakdown by category of patients (i.e. adults, children and the elderly) and by whether the cases were fatal;
(2) how the respective numbers of people receiving influenza vaccination under the Childhood Influenza Vaccination Subsidy Scheme and the Elderly Vaccination Subsidy Scheme since the increase in the subsidy per dose of vaccine for such schemes in October last year compare with the relevant numbers in the same periods of the past three years;
(3) whether it has plans to further step up publicity to educate members of the public who suspect themselves of having infected with influenza to take measures to prevent the spread of the viruses (such as wearing masks and reducing visits to crowded places);
(4) as some members of the public are worried about being infected with influenza when taking public transport, whether the Government will deploy manpower to conduct hands-on monitoring as to whether the air quality in railway train compartments and platform areas, franchised buses compartments and major transport interchanges meets the requirements of the Practice Note for Managing Air Quality in Air-conditioned Public Transport Facilities; as it has been reported that the carbon dioxide concentration inside the compartment of a half-full bus stays around 2 100 parts per million, which exceeds the "Good Class" level of the Indoor Air Quality Objectives formulated by the Environmental Protection Department by more than 100% and reflects the inadequacy of fresh air inside bus compartments, thus making it easy for influenza viruses to spread, whether the Government will consider afresh requiring franchised bus companies to employ buses with windows that can be opened to admit fresh air;
(5) given that the Government distributed disinfectant packs on the streets to disseminate hygiene and epidemic prevention messages during the outbreak of the Severe Acute Respiratory Syndrome in Hong Kong in 2003, whether the Government will consider employing such method again to disseminate messages on the prevention of influenza infection;
(6) whether it has stepped up disinfection of public places managed by government departments (such as public libraries); if it has, when such work started and of the specific arrangements; whether it has carried out disinfection of public library collections, such as books; if it has, of the details;
(7) if it knows whether any healthcare workers of public hospitals worked overtime or cancelled their leave last month in order to deal with the influenza outbreak; and
(8) given that influenza vaccination is suspected to have triggered the onset of myasthenia gravis in a healthcare worker earlier, whether the Government knows if there were cases of other serious diseases triggered by influenza vaccination in the past three years?
Reply:
President,
Hong Kong usually experiences two influenza seasons every year, the first one normally between January and March, and the other in July and August. The 2014/15 winter influenza season already started in late December 2014. The activity of seasonal influenza has continued to increase since then and rapidly reached a high level in mid to end of January this year. Since early February, some surveillance data have shown that influenza activity started to decrease from the peak levels. Seasonal influenza affects large segments of the community and may lead to serious infections especially among certain at-risk populations. Hence, the Government maintains alert against influenza outbreaks and has taken a series of measures to prepare for the influenza season.
My reply to different parts of the question is as follows:
(1) Seasonal influenza is a common communicable respiratory disease in Hong Kong. The majority of infected cases in the community are not tested and confirmed. Given its prevalent nature, seasonal influenza is not a statutory notifiable disease in Hong Kong. The Centre for Health Protection (CHP) closely monitors influenza activity in the community through its surveillance systems. It also monitors the weekly hospital admission rate associated with influenza in public hospitals based on patient discharge diagnoses. In collaboration with the Hospital Authority (HA) and private hospitals, the CHP operates an enhanced surveillance system during influenza seasons to collect information on cases of influenza-associated admission to intensive care unit or death cases among patients aged 18 years or above. As regards children, an ongoing surveillance system is in place to monitor cases of severe paediatric influenza-associated complication or death cases among children aged under 18 years. The surveillance data for each summer and winter influenza season in the past three years are set out at Annex 1.
(2) The number of people vaccinated in 2014/15 (as at March 15, 2015) under the Childhood Influenza Vaccination Subsidy Scheme and the Elderly Vaccination Subsidy Scheme is about 4.1% more than the total number of people vaccinated under the two schemes in the full year of 2013/14. As the 2014/15 season has not finished yet, the number of people receiving influenza vaccination is expected to increase for the rest of the year.
The numbers of people vaccinated under the Childhood Influenza Vaccination Subsidy Scheme and the Elderly Vaccination Subsidy Scheme this year and in the past three years are shown in Annex 2.
(3) and (5) On the prevention of influenza, the CHP has stepped up publicity and health education activities to promulgate advice on personal and environmental hygiene and to remind the community to stay vigilant against the disease. The CHP has produced a variety of health education materials on the prevention of influenza, including a thematic webpage, television (TV) and radio announcements in the public interests, guidelines, pamphlets, posters, booklets, frequently asked questions and exhibition boards. Various publicity and health education channels, e.g. websites, TV and radio stations, health education hotline, newspapers and media interviews, are used to promulgate health advice. The CHP also launched a dedicated Facebook page and a YouTube channel in February 2015, with a view to further disseminating information on health promotion as well as disease prevention and control to members of the public, especially the younger generation. In addition, it has distributed health education materials to public and private housing estates, healthcare institutions, schools and non-governmental organisations (NGOs), etc. The CHP maintains close contact with stakeholders, including government bureaux and departments, hotel and guesthouse associations, property management associations, Hong Kong Housing Society, District Councils, Healthy Cities, NGOs and ethnic minority groups, and updates them on the latest influenza activity and preventive measures. Their co-ordination and support are also solicited to enhance the publicity of related health messages. The main message is to advise the public to maintain good personal and environmental hygiene. They should put on surgical masks to avoid infecting others when respiratory symptoms develop. When influenza is prevalent, they should avoid going to crowded or poorly ventilated public places. High-risk groups should consider wearing surgical masks to prevent infection especially when staying in such places.
The CHP has issued notices to doctors, hospitals, kindergartens, child care centres, primary and secondary schools as well as residential care homes for the elderly and the disabled to alert them to the latest influenza situation and the preventive measures to be adopted. Students with fever or respiratory symptoms are strongly advised not to attend school till 48 hours after the fever has subsided, and staff with fever or respiratory symptoms should also refrain from work.
The Government has no plan to distribute disinfectant packs on the streets to promote the prevention of influenza at present. Nevertheless, it has liaised with the District Councils, Healthy Cities Projects and NGOs, distributing to them health education materials to facilitate dissemination and promotion of health messages in the community.
(4) In 2003, the Environmental Protection Department (EPD) issued the "Practice Note for Managing Air Quality in Air-conditioned Public Transport Facilities – Railways (Practice Note 2/03)" (Practice Note on Railways) and "Practice Note for Managing Air Quality in Air-conditioned Public Transport Facilities – Buses (Practice Note 1/03)" (Practice Note on Buses). Railway and franchised bus operators have followed the practice notes to regularly monitor the level of carbon dioxide concentration of their facilities. This can help ascertain whether there is sufficient ventilation to maintain indoor air quality.
The indoor carbon dioxide concentration standard is set with reference to the duration of stay of a person at a premises. In general, the level of the ceiling of carbon dioxide concentration would go down when the duration of stay would go up. In the course of setting the standard of carbon dioxide concentration for air-conditioned railway and franchised bus facilities, EPD commissioned the Hong Kong Polytechnic University to conduct researches and consulted experts and professional organisations on indoor air quality and air-conditioning system. Taking into account their views, EPD adopted the standards of 2 500 ppm for Level 1 and 3500 ppm for Level 2 in their practice notes to provide guidance for railway and franchised bus operators in managing indoor air quality of their facilities. Both levels would not cause health concern to the public.
The MTR Corporation Limited (MTRCL) has been following the Practice Note on Railways to regularly monitor the carbon dioxide concentration level in the indoor areas of railway stations as well as air quality inside train compartments. Indoor air quality is also ensured vide the ventilation system of railway stations and train compartments. In daily operation, the air-conditioning system of railway stations would be adjusted to automatically bring in outdoor fresh air. In addition, MTRCL regularly arranges cleansing of filters of the ventilation system and air-conditioning system. According to MTRCL, air quality in the MTR system is in compliance with the requirements stipulated in the practice note. Besides, to prevent the spread of influenza, MTRCL has been following the guidelines provided by the Department of Health (DH) to step up cleansing of its stations, train compartments and other facilities in the stations (including escalators, ticket machines as well as entry and exit gates).
To enhance the quality of bus service and cater for passenger needs, the whole of the franchised bus fleet is equipped with air-conditioning system. Franchised bus companies have all along been regularly monitoring air quality inside bus compartments to ensure they are in compliance with the Practice Note on Buses. To prevent the spread of influenza, franchised bus companies have followed the DH's guidelines to step up the cleansing of bus compartments (including the floor, hand rails, seats, glass windows and dust filters) and bus body. Currently, the air-conditioning system of buses is designed for models which cannot have their windows opened. It is fitted with sensors and thermostats to enable the temperature and humidity inside the bus compartments to be suitably adjusted according to the difference between the interior and exterior temperature and humidity. Since 2003, newly purchased buses have been fitted with fresh air exchange and filtering system to allow better ventilation. In light of the above, franchised bus companies do not have any plan to have on air-conditioned buses windows which can be opened.
With regard to the Public Transport Interchanges (PTIs), the Government has set down specific requirements on the design, ventilation system, operation and maintenance of these facilities, in accordance with the EPD's "Practice Note on Control of Air Pollution in Semi-confined Public Transport Interchanges" issued in 1998. Meanwhile, the Government would conduct air quality measurement at PTIs on a regular basis.
To prevent the spread of influenza on public transport, the Transport Department (TD) will continue to liaise with the public transport operators and disseminate the latest information provided by the DH to them so that appropriate preventive measures can be taken. TD and EPD will actively follow up on complaints in relation to indoor air quality inside the compartments of railways and franchised buses.
(6) Public libraries under the Leisure and Cultural Services Department have all along followed the guidelines of the DH by conducting regular cleaning of the library facilities and adopting measures to prevent the growth and spread of bacteria. Apart from deploying workers to clean library facilities with diluted bleach every day, public libraries have arranged weekly large-scale cleaning operation to disinfect furniture, equipment and facilities thoroughly prior to readers' visit when libraries are closed for public service. Public libraries have also arranged regular cleaning of air-conditioners and ventilation equipment with a view to maintaining the environmental hygiene and cleanliness of libraries as a whole. When handling library materials returned by readers and carrying out routine shelving of library materials, library staff will remove those with stains or dirt immediately for cleaning and disinfection. Moreover, alcohol-based handrub is available at all public libraries for the public to clean and disinfect their hands.
(7) To cope with the surge in demand, the HA formulated a comprehensive response plan before the winter surge period, major initiatives include opening of beds to enhance capacity and improve patient flow.
Hospitals also encouraged staff to increase work hours to handle extra workload (including more frequent ward rounds during weekends and holidays to facilitate discharge of suitable patients and transfer of stable patients staying in acute hospitals to convalescence units or hospitals within the cluster) by providing special allowances and leave encashment. In addition, the HA also enhanced support from different staff groups to implement winter surge measures.
(8) "Adverse event following immunisation" refers to the development of a health problem after someone gets vaccinated. It may or may not be caused by the vaccination. Some adverse events may occur by chance during the post-vaccination period and are not related to vaccination. Hence, when an adverse event is reported, it does not necessarily mean that the event is caused by vaccination.
Neurological adverse events known to be related to influenza vaccination include Guillain-Barré
Syndrome (GBS), which normally develops within five days to six weeks after vaccination. However, there is no science literature to support the correlation between myasthenia gravis and adverse events following influenza vaccination.
The occurrences of GBS and other serious neurological adverse events among vaccinated persons within five days to six weeks after vaccination in the influenza seasons of the past three years (as at noon, March 16, 2015) are as follows:
Year GBS Other serious neurological
adverse events
2012/13 1 0
2013/14 1 2
2014/15 0 1
Ends/Wednesday, March 18, 2015
Issued at HKT 17:17
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