Hong Kong looks at relationship between climatic factors and infectious diseases

The relationship between climatic factors and infectious diseases is being studied by the Hong Kong Government to see whether there is a major or direct link, Secretary for Health, Welfare & Food Dr York Chow says.

He told the Legislative Council today the Department of Health and the Food & Environmental Hygiene Department are monitoring international and local studies on seasonality or climatic factors being one of the contributing factors to the transmission potential of infectious disease. They will take the findings into account when updating their public health control strategies and contingency plans for infection outbreaks.

The World Health Organisation has recognised that climatic effects associated with global warming may raise the transmission potential for some vectors and waterborne diseases like mosquitoes and pathogenic organisms by affecting their lifecycle dynamics, and by contaminating water or food.

Dr Chow said Government departments are investigating the relationship between climatic factors and infectious disease locally. He said the Centre for Health Protection's scientific committees, with assistance from the Hong Kong Observatory, have examined the relationship between climatic variables, including temperature and humidity, and selected local infectious diseases of public concern, like Japanese encephalitis and Dengue fever.

The observatory recently performed a literature review on the possible link between climate and outbreaks of SARS and avian influenza for the World Meteorological Organisation Commission of Climatology.

On Dengue fever, Dr Chow said overseas studies have found warmer temperatures can facilitate its spread by favouring mosquito growth, making them more active, extending their range of movement and habitats and lengthening the disease's transmission season.

But he said in Hong Kong the majority of Dengue cases are imported, adding that the rising trend may be attributable to an interplay of enhanced awareness of infectious disease among healthcare professional and the public, more frequent travel, increased disease activity in other areas and a better disease surveillance system.

Dr Chow said Hong Kong has established effective disease information exchange mechanisms with the WHO and health authorities on the Mainland and other places, which cover diseases that may be affected by global warming, while the observatory will maintain regular liaison with the WMO and China Meteorological Administration on global climate change.