epidemiological information from the Chinese Mainland it was considered advisable to continue to regard all Chinese ports east of Canton as being suspected areas of smallpox infection,
50. Vessels inspected at Quarantine anchorages during the year numbered 4,543, carrying 67,076 passengers and 233,378 crew as against 4,073 ships, 54,651 passengers and 225,932 crew in 1956. There was an increase in air traffic during the year but fewer passengers arrived from infected areas. A total of 23,660 passengers were inspected as against 25,118 in 1955. The routine spraying of all aircraft with insecticide before arrival was insisted upon. 666,365 persons entered the Colony by the land frontier station at Lo Wu as compared with 113,871 in 1955. Of these 596,954 were vaccinated against smallpox. Il cases of suspected leprosy were detected and handed over to the Immigration Authorities for disposal.
61. Four launches and one fumigation barge were provided by the Marine Department for port health work. The four launches are fitted with radio telephones and carry first aid equipment. They also provide an ambulance service and were used for miscellaneous duties such as the transport of sick, medical stores, lepers and specialists to and from the oullying islands.
62. 45 ships were fumigated with sulphur dioxide and 29 with cyanide. 125 were granted deratting exemption certificates as against 184 in 1955. The fumigation staff also carried out disinsecting of vessels and fumigation of cargo in lighters.
58. In accordance with the Asiatic Emigration Ordinance, the inspection of vessels carrying over 20 unberthed passengers travelling as emigrants was carried out as usual. 62 ships carrying 10,173 emigrants were inspected during the year as against 69 ships with 6,389 emigrants in 1955,
54. Although no longer required for international voyages, Bills of Health continued to be sought by masters of vessels. 1,823 Bills of Health were issued, including 70 to H.M. Ships or United States Naval vessels, as against a total of 2,216 in
1955.
56. 3 Port Health Vaccination Centres were maintained, 2 on the Island and 1 in Kowloon, for the convenience of persons
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requiring certificates for international travel. They also provid- ed free prophylactic vaccinations to members of the public.
56, International Sanitary Regulations require control of aedes mosquito breeding in ports and regular inspections for presence of mosquito larvae were carried out on small craft in the harbour. Mosquito breeding was negligible and no aedes aegypti larvae were found on any of the 5,722 junks inspected during the year. Aedes aegypti, although not found on shore in recent years, was the predominant species of mosquito found breeding on junks in the harbour in 1963, and since then the mosquito has been eliminated by control measures which depended largely on the cooperation of junk masters.
57. The dock ares and airport are included in the rodent control scheme for the Colony and returns of rodents destroyed and spleen smears examined for F.pestis were submitted weekly to the Epidemiological Intelligence Station, Singapore.
58. A constant check was maintained on the purity of drink- ing water supplied to ships by bacteriological examination of weekly samples from water boats and dock hydrants, and immediate remedial action was taken when necessary by the Water Authority or Port Health Office. 495 samples were taken
from water boats and doek hydrants and were submitted to the Pathological Institute for bacteriological examination, 31 sam- ples did not conform to the standard of purity. 61 samples of water were taken from ships on request; of these 22 were sub- standard.
59. A weekly exchange of epidemiological information was maintained with the World Health Organization Epidemiological Intelligence Station, Singapore. Hong Kong, because of its use- ful radio station, is frequently contacted by ships at sea seek- ing medical advice. During 1956, 16 ships requested "PORT HEALTH" Hong Kong for advice regarding treatment of sick persons on board and the period under treatment in each case ranged from one to seven days.
Tuberculosis.
60. The combined effects of a refugee problem of gigantic proportions and overcrowding probably without parallel have produced in the community a tuberculosis infection rate higher than in any other part of the world. Despite these facts there
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