M 20
III. HYGIENE AND SANITATION.
(A) General review of work done and progress made.
(I) Preventive measures.
(a) Mosquito and insect-borne diseases.
52. (i) Malaria. A report on the activities of the Malaria Bureau during 1939 is given under Section IX, Scientific.
53. The influence of the large number of refugees on the incidence of malaria in the Colony can be seen in the increase in the number of deaths from malaria, 1,492 as compared to 733 in 1938. The infection rate of twenty-five per centum amongst the inhabitants of one of the refugee camps gives ample proof of the danger of refugees as a source of infection for the local anopheles.
54. The permanent canalization of 2,160 feet of streams in the vicinity of the Queen Mary Hospital, at a cost of $17,580, is an important measure towards safeguarding that locality. It must, however, be pointed out that the Colony's comparative freedom from malaria in the urban areas is due to temporary anti-malarial measures, such as draining of streams and regular oiling, carried out by the staff of the Malaria Bureau. Owing to critical times, uncertain finances and heavy costs, permanent anti-malarial drainage can only be introduced gradually over a period of years.
55. (ii) Yellow fever. No case of this disease has been recorded nor can its introduction be regarded as likely to occur while the present stringent control measures are maintained.
56. (iii) Filariasis. As in previous years, the incidence of filariasis is negligible.
(b) Epidemic disease.
57. (i) Plague. No case of plague occurred during the year. Anti-rodent measures, such as systematic trapping and house cleansing, were continued.
221,200 rats were trapped, 24,447 of them alive.
Spleen smears from a certain number were examined daily, but in no case was P. pestis found.
58. Measures to prevent the introduction of plague from shipping were maintained.
59. An investigation of the local flea population, carried out by the Malaria Bureau, shows that, of 4,496 fleas examined, eighty-nine per centum were Xenopsylla cheopis. Details are given in the malariologist's report (Section IX, Scientific).
60. (ii) Cholera. (In addition to what has been said about cholera in an earlier part of this report, it is of interest to note that thirty-four cases were imported from various districts in China. There is little doubt that the constant stream of immigrants to the Colony and the consequent overcrowding is largely, if not solely, responsible for the disease attaining epidemic proportions.