Replies to LegCo questions
LCQ22: Seasonal influenza
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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LCQ 22 Annex