Replies to LegCo questions
LCQ17: Studies on relationship between local climatic factors and infectious diseases
Following is a question by the Dr Hon Kwok Ka-ki and a written reply by the
Secretary for Health, Welfare and Food, Dr York Chow, in the Legislative Council
today (May 11):
Question:
It has been reported that the Hong Kong Observatory has advised that Hong Kong
and other regions around the globe have been affected by warming, and it is
projected that the annual mean in Hong Kong in the last decade of this century
will be 26.5 degrees Centigrade, 3.5 degrees higher than the average recorded
between 1961 and 1990. In this connection, will the Government inform this
Council whether:
(a) it has conducted researches on the relationship between global warming and
infectious diseases;
(b) it has conducted researches on the causes of the increase in the number of
infectious disease (such as dengue fever) patients, and on the relationship
between such increase and global warming;
(c) it has assessed the impact of the infectious diseases caused by global
warming on the local health care system (for instance, whether health care costs
have risen); and
(d) it has maintained liaison and regular exchange with the World Health
Organization and Mainland health authorities regarding the relationship between
global warming and infectious diseases; if not, whether it has plans to
establish a relevant research and exchange mechanism with the international
medical and health authorities and the Mainland health authorities?
Reply:
Madam President,
(a), (b) and (c) The Department of Health (DH) has been closely monitoring
researches and studies undertaken by international health authorities such as
the World Health Organization (WHO) which has recognised that, globally
speaking, climatic effects associated with global warming like temperature
changes and rainfall may increase the transmission potential for some vector and
water-borne diseases by affecting the life cycle dynamics of relevant vectors,
for example, mosquitoes and pathogenic organisms, and by contaminating drinking
water, recreational water or food.
Government departments have also conducted or participated in researches and
studies on the relationship between climatic factors and infectious diseases in
the local context. For example, the Scientific Committees set up under DH's
Centre for Health Protection (CHP), with the assistance from the Hong Kong
Observatory (HKO), have examined the relationship between climatic variables,
including temperature and humidity, and selected local infectious diseases of
public concern such as Japanese encephalitis. Dengue fever is another infectious
disease which the CHP has been studying and watching closely. Moreover, the HKO
has recently performed a literature review on the possible link between Severe
Acute Respiratory Syndrome and climate as well as that between Avian Influenza
and climate in their past outbreaks for the Commission of Climatology of the
World Meteorological Organization (WMO)(Note 1).
In the above studies and review, it was noted that seasonality or climatic
factors may be one of the contributing factors to the transmission potential of
these diseases although whether it is a major or a direct link remains to be
confirmed.
As far as dengue fever is concerned, overseas studies reveal that warmer
temperature may facilitate its spread by favouring the growth of mosquitoes (the
vector for the transmission of the disease), making them more active, extending
their range of movements and habitats and lengthening the transmission season
for the disease. Nonetheless, in Hong Kong, it is also noted that majority of
the reported dengue fever cases in recent years, which are on a rising trend,
were actually imported cases. The rising trend may be attributable to an
interplay of various factors including enhanced awareness of infectious diseases
among healthcare professional and the public, more frequent international
travelling, increased disease activity in neighbouring places and our enhanced
disease surveillance system, etc.
DH and Food and Environmental Hygiene Department (FEHD) will closely monitor the
developments and take note of the results of international and local studies on
the relationship between climatic factors and infectious diseases when they
formulate and update their public health control strategies and contingency
plans for infectious disease outbreaks. In this connection, DH has put in place
disease surveillance and public health control mechanisms in collaboration with
other departments to prevent and control the spread of infectious diseases
having regard to seasonality and climatic factors. Apart from launching annual
inter-departmental territory-wide anti-mosquito campaigns to raise public
awareness, FEHD would conduct thematic operations in sustaining the efforts on
mosquito control.
(d) DH has established effective disease information exchange mechanisms with
the WHO as well as health authorities in the Mainland and other places. These
mechanisms cover infectious diseases which may be affected by global warming. DH
would also take into account climatic factors in its studies on infectious
diseases as appropriate. In this connection, it will seek relevant inputs and
cooperation from the HKO, which maintains regular liaison with the WMO and China
Meteorological Administration, etc. on matters relating to global climate
change.
Note:
(1) The WMO is an intergovernmental organisation with a membership of 187 Member
States and Territories. It is the specialised agency of the United Nations for
meteorology (weather and climate), operational hydrology and related geophysical
sciences. The WMO Commission of Climatology is responsible for promoting and
facilitating activities relating to climate and its relationship with human
well-being, human activities, natural ecosystems and sustainable development.
Ends/Wednesday, May 11, 2005
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