voluntary patients from the Government Drug Addiction Clinic to the Castle Peak Hospital for treatment during the period of withdrawal from the drug, and thereafter to transfer them to Shek Kwo Chau for a course of rehabilitation and training which will fit them to retum to work. Re-employment and follow-up activities will be a combined effort shared between the Government Departments and Voluntary Agencies concerned.
II. The inauguration of a 'fiying doctor' service to remote villages in the New Territories in March 1961 has proved to be very popular and worthwhile. Using helicopters of the Hong Kong Auxiliary Air Force, visits are paid weekly to 7 centres where minor ailments are treated, cases of emergency illness evacuated to hospital and much health education given. In remote rural areas a curative service is always the spear head of health education in the prevention of disease either through immunization or the practice of simple hygiene based on some elementary knowledge of disease processes and how they can be avoided.
12. The most significant event of the year was the re-appearance of cholera during August 1961 after an absence of 15 years, presumably introduced by the migrant small boat population. This followed an outbreak of paracholera El Tor in the Kwangtung Province of China and the subsequent occurrence of cases in Macau. The infection in Hong Kong was proved to be due to the El Tor type of vibrio cholerae of the Ogawa group and resulted in a total of 77 confirmed clinical cases. In addition, investigation of 731 contacts of clinical cases isolated at the emergency Quarantine Centre resulted in another 53 confirmed infections in contact carriers without symptoms. There was a total of 15 deaths, of which seven occurred before admission to hospital.
13. The first two cases were reported on the 16th August and the last one on the 8th of November. However, the majority of cases occur- red during the first 12 days when 52 patients suffering from clinical cholera were admitted to hospital; subsequently 24 cases occurred during the next 26 days and the emergency phase was over by the 23rd September. Thereafter one isolated case occurred on the 8th of November, coming to light only because all cases of gastro-enteritis were being investigated for vibrio cholerae infections as a routine.
14. The public reaction to the situation was most heartening. There was no hint of panic and full co-operation in the emergency measures applied to control the outbreak was evident from the start. There was an unprecedented demand for inoculation and, between the 14th August
when precautionary measures were first applied and the 25th August, 1,855,830 persons were given vaccine. By the end of the inoculation campaign sample surveys indicated that over 75% of the total popula- tion had been immunized.
15. Strict and comprehensive measures of quarantine and environ- mental hygiene were applied throughout the Colony and were accepted readily. The cardinal feature was the isolation, in the emergency Quarantine Centre at the Chatham Road Camp, of all immediate con- tacts of the confirmed clinical cases. All confirmed contact carriers were further isolated in another section of the Centre and given prophylactic treatment with antibiotics, to which the vibrio cholerae isolated were known to be susceptible, until three negative rectal swabs in succession had been obtained. These particular quarantine measures are believed to have had a significant influence in preventing an outbreak of epidemic proportions with many deaths. In conjunction with the early treatment in hospital of clinical cases, protection of the water supplies and strict control of markets and food hawkers there seems to be no doubt that the initial widespread dissemination of vibrio cholerae, indicated by the sporadic appearance of clinical cases, was contained most effectively by this isolation of all immediate contacts of those suffering from overt cholera.
16. The high degree of public co-operation is underlined by the fact that there was no concealment of cholera cases or deaths. Memories of cholera in the past and knowledge of what had happened or what was happening to relatives in neighbouring China must have had no small influence on this favourable reaction of those most vulnerable to cholera-the boat people, the waterside communities and the grossly overcrowded tenement dwellers.
17. During February and March 1962 a further cholera immuniza- tion campaign was launched in anticipation of a possible recurrence of cholera in the summer of 1962. The results were encouraging amongst the groups most at risk, where an average of over 80% of cover was achieved. The response in the urban arcas was not so good but the indications are that, over-all, some 53% of the total population had received cholera vaccine by the end of April.
18. Routine laboratory investigations of all cases of gastroenteritis. of water supplies, of night-soil and of fruit and other potential vehicles of infection have been continued throughout the year with entirely negative results since November 1961.
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