population, the widespread traditional wet cultivation and the un- protected contiguous borders and islands. Therefore, the main line of defence against malaria for disciplined groups stationed in the New Territories consists of such anti-larval measures as may be practicable in the vicinity, screening where possible and chemo-prophylaxis. There were 19 cases of malaria notified from police and services personnel during the year.
202. The cost of the control measures during the year under review was 36 cents per head of population living in the protected areas.
Incidence of Malaria
203. Malaria is a notifiable disease, and the returns of the past five years are set out in Table 15.
Year
1957
1958
1959
1960
1961
TABLE IS
MALARIA 1957-61
Cases Motified
Deathy
447
0
639
1
442
1
1
EER
$12
204. The endemicity of malaria varies, as was proved by Malacio- metric indices obtained from a survey carried out during the year in children between 2-9 years of age in 14 villages in the New Territories. Spleen and parasite rates ranged from 0% to 40.2% and from 0% to 20% respectively.
205. The total number of cases of malaria notified during 1961 was 812 as compared with 833 in 1960. Notifications of 91.3% of all cases were from outside the protected areas; 43.8% of the cases came from the area surrounding the small town of Sai Kung and 26.2% of the total from Lantau Island. Of the parasites identified 96.4% were P. vivax, 2.4% P. falciparum 10% P. matarice and 0.1% were undetermined.
206. A scheme to control malaria in the Sai Kung District is under consideration and an entomological survey was conducted in the area between July and October 1961 to study the anopheline larval habitat and relative species abundance. A. minimus and A. jeyporiensis var. candidiensis, the chief malaria vectors in the Colony, comprised 11.4% and 2.1% of the six anopheline species encountered during the survey.
48
Laboratory
207. The Bureau laboratory continued to carry out routine identi- fication and dissection of mosquitoes and the examination of blood smears collected at surveys. Susceptibility tests of anophelines to various insecticides were conducted from time to time and the results forwarded to the World Health Organization.
SOCIAL HYGIENE SERVICES
208. This service which is the responsibility of the Social Hygiene Specialist consists of three branches dealing with dermatology, venereal diseases and leprosy. Facilities for the diagnosis of skin conditions are of considerable importance in bringing to light cases of latent syphilis and of early leprosy. Accordingly, the service is organized to provide 9 Centres for purely dermatology clinics; in addition there are thirteen social hygiene clinics, where venereal infections and leprosy undergo investigation and treatment and a number of cases of skin disease also attend, The Wanchai Hospital provides in-patient accommodation for the treatment of skin disease in women and beds for male patients are available at the Lai Chi Kok Hospital.
209. During the year the post of Social Hygiene Specialist remained vacant and the Principal Medical and Health Officer (Health) at Medical Headquarters was responsible for the administrative aspects of the service. It is believed that the Specialist post will be filled by the middle of 1962.
Dermatology
210. The dermatology clinics held at the nine centres recorded a total attendance of 6,094 cases referred for an opinion. At the Social Hygiene Clinics there were a further 12.173 first attendances for skin complaints which is 47.2% of the total of new cases seen at these clinics.
211. Biopsies, microscopic and culture examinations for fungi and tests for uroporphyrin are carried out at the clinics. Patients requiring radio-therapy for skin conditions are referred to the Sai Ying Pun Polyclinic.
212. Griseofulvin is now the treatment of choice for ringworm of the body, hair and nails. Neurodermatitis is treated at the Wan Chai Hospital with hydrocortisone lotion, using the vibro puncture technique. Discoid lupus erythematosis responds well to Plaquinol which has proved to be one of the less toxic chloroquin derivatives.
49