PUBLIC HEALTH
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to agricultural lands where the application of oil would be unsuit- able.
In certain instances, the Malaria Bureau also undertakes to deal with culicine mosquito breeding. Against breeding of Culex fati- gans, Diazinon Dispersible Powder has been found very useful particularly when breeding is located in sumps.
For Aedes togoi, which breeds profusely in the brackish water of numerous rock pools along the sea-shore, gammexane brick still retains its effectiveness after 7 to 8 years of continuous use.
Up to the present, except in the few selected areas mentioned above, no overall anti-malaria programme has been undertaken in the New Territories and chemoprophylaxis is still advisable there.
The Malaria laboratory carries out the work of identification and dissection of mosquito specimens, staining and examination of blood smears, field tests on the efficacy of various insecticides, and tests of the susceptibility of anophelines to insecticides.
Poliomyelitis. A total of 262 cases with 41 deaths from this disease was reported in 1958. There was an abrupt rise in incidence from 9 cases in April to 53 cases in May. The peak monthly total of 82 cases was reached in June; in July and August a slight decline was observed and an abrupt fall to only 4 cases followed in September. 217 or 82.8% of all cases occurred in Chinese infants or children under 4 years of age. The 13 non- Chinese patients notified were mainly members of the Armed Services or their families and 'included 2 adult cases arriving in the Colony after contracting the disease elsewhere. Males appeared to be more affected than females in the proportion of 3 to 2.
Nearly all cases suffered the paralytic form of the disease and type 1 poliomyelitis virus was recovered from specimens sent to the Virus Reference Laboratory in Singapore.
This is the first year on record where the incidence of this disease has shown such a clear-cut rise in the summer months. The higher incidence recorded this year can partly be explained by the much improved reporting of the disease which is now evident as a result of increased public awareness, more resort to practitioners of Western medicine and better appreciation of the benefits of physiotherapy.