HEALTH
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part in malaria transmission. Plasmodium vivax is the predominant parasite responsible for the infection.
Malaria control in the urban areas is based chiefly on anti-larval measures consisting of draining and clearing streams, ditching and oiling. Anti-malaria oil continued to be employed as the main larvicide, but malathion, diazinon or BHC were used on a limited scale in areas where the application of oil is not suitable. These anti-larval operations against anopheline breeding afford protection from the infection to approximately 80 per cent of the population. None of the few cases appearing in the urban areas during the year could be attributed to breakdown of these control measures. In the remainder of the New Territories, the background of which is essentially rural, the adoption of either anti-larval or anti-adult measures is not feasible at present and chemoprophylaxis remains the main protection.
A continuous immunization campaign against diphtheria has been in progress since 1959 interrupted only by the need for anti- poliomyelitis and cholera inoculation drives. House-to-house visits are conducted in resettlement estates or other crowded areas, and teams of inoculators visit squatters both on hillsides and on rooftops. Every effort is made to inform parents of the dangers of the disease and of facilities available for the protection of their children.
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As a result there has been a steady fall in the incidence of the disease, from a total of 2,087 cases in 1959 to 699 in 1964. The case fatality rate fell from 9.9 per cent in 1963 to 5.4 per cent this year; most deaths occur in non-immunized children who present with advanced laryngeal or pulmonary complications, due to delay in seeking proper medical attention.
A late outbreak of enteric fever brought figures for the year up to about the same as 1963. Free inoculation is available and the usual control measures are enforced with special attention to the detection of carriers amongst food handlers.
Since the mass anti-poliomyelitis campaign, using Sabin-type oral vaccine in the first quarter of 1963, free oral vaccine has been offered at all maternal and child health centres and by inoculation teams engaged in certain other campaigns. The incidence of the disease remained low, a total of 37 cases and three deaths being