1. GENERAL REVIEW
THE Colony of Hong Kong occupies a land area of 3981 sq. miles, and the estimated mid-year population in 1963 was 3,592,100, of which 85% was concentrated in the urban areas of Hong Kong Island and Kowloon. It is a young population, approximately 40% being below the age of 15 years and only 5% over age of 60.
2. During the year, the major problems of overcrowding and of environmental hygiene, posed by pre-war tenement buildings and aggrega- tions of squatter and roof-top dwellings, were aggravated considerably by a serious shortage of water, the worst in the Colony's history; the total rainfall for 1963 amounted to only 35.48 inches, representing less than 42% of the normal annual rainfall. Accordingly, severe water restrictions had to be enforced and the great majority of the population were restricted to a four-hour mains supply every fourth day. As could be expected, many turned to other sources for augmentation of their water supply, and intensive chlorination was undertaken wherever possible of wells and of water obtained from other sources such as hill streams.
3. Despite the twin hazards of severe restriction of mains supply and use of water from suspect sources, there were only slight increases in the incidence of gastro-intestinal diseases. Even the re-appearance of cholera El Tor in June did not result in a widespread outbreak. In all, 115 cases of this disease were reported during 1963, occurring sporadi cally between 29th June and 21st December; one further case was notified in February, 1964. The outbreak is reported in detail elsewhere in this report.
4. In spite of all the environmental hazards, the community health record during the year remained remarkably good. Both the crude death rate and the infant mortality rate declined further, the former to 5.5 deaths per 1,000 population and the latter to 32.9 per 1,000 live births. For the first time in five years the neo-natal mortality also showed a fail, from 21.2 per 1,000 live births in 1962 to 18.9 per 1,000 in 1963.
5. A gratifying feature of the year was the great reduction in the incidence of paralytic poliomyelitis as a result of the mass vaccination campaign, using a Sabin type oral vaccine, which was conducted during the first quarter of 1963. Following this campaign, there was a sharp
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