40
APPENDIX (B)
REPORT OF
THE MALARIA BUREAU.
The beginning of the year found the Malaria Bureau in a very strong position. Much valuable material assistance had been furnished by the Navy, Army, and R.AT. anti-malaria unils, and with the employment of a large labour force (600 coolies) augmented by 1500 Japanese prisoners, the main residential areas were well on their way to being controlled.
Staff.
Our former inspectorate had all returned to duty, On 3rd. February, Dr. R. B. Jackson, the former Government Malariologist arrived from England. Dr. J. E. Mackie returned to England on April 3rd., and resumed duty on October 27th.
Dr. R. B. Jackson returned to England on December 27th, Three inspectors were pro- moted as senior inspectors in May, and one inspector resigned in December. Three probationer mularia inspectors were appointed in September, November and December.
Field Work (Hongkong)
At the outset, the Bureau had few tools, no oil and no transport. On the Island the Navy made themselves responsible for supplying anti-malaria oil, and undertook some stream training in the outlying districts of Aberdeen, Repulse Bay and Stanley. These areas were taken over completely by the Malaria Bureau, in August. In September, the A.P.C. were able to supply "malariol", In all other areas, Queen Mary Hospital, Happy Valley, Tai Hang, Causeway Bay, the Bureau undertook full control. In October, with the rehabilitation of Mount Cameron and Shek O, anti-malaria work was commenced in these areas. A severe outbreak of malaria at the Tytam Tuk Pumping Station necessitated work in that area, from August. In June, it was found possible to reduce the labour force from 600 to 300.
Kowloon.
On the Peninsula side, the work was greatly helped by the liberal supply of oil, tools, and transport which were made available to us by the 34th Indian Anti-Malaria Unit under Capt. Mukherjee. Starting with the clearing of the original anti-malaria drainage in Polo Valley, work was extended East and West for a half-mile belt until control had been obtained from Lai Chi Kok Bay to the Amoy Canning factory beyond the Airport. The R.A.F. Malaria Unit which was working round the Air Port was withdrawn in April, and the Bureau took over complete control of the Kui Tak area. In all other areas the Bureau had been in complete control throughout Tables showing the results of checking catches larval surveys done in the year. connection with this work are appended.
Laboratory.
In spite of the fact that none of the equipment for the Laboratory ordered from the Crown-Agents arrived in 1946, a considerable amount of work was done with make-shift gear, the results of which are appended. Soma 1,700 anophellne larvae and 315 culicine larvae were identified in 82 surveys; and in 114 catches, 124 adult anopheline and 1459 adult culicines. No new anophelines were encounted, but one new species of Ficalbia was found in surveys at Shek O. It has been sent to the British Museum for identification. Facilities were also given to the Navy and Army anti-malaria Units, and all our previous records were placed at their disposal.
Aerial Spraying of D.D.T.
Several areas of the Colony were sprayed with D.D.T. on a few occasions by Naval aircraft. This unit arrived rather late to be of real use in the anti-malarial campaign, and the nature of the breeding places in Hongkong are somewhat unsuit- able for this method of attack.
Cooperation with other departments and public bodies.
At the invitation of the Portuguese Government, & malaria survey was made in January by the Advisor in Malariology (Dr. J. B. Mackie), and a report with recommendations was sent through the Director of Medical Services. At Ping Shan and Ha Tsun, numerous malaria surveys of the proposed new airfields were carried out for the R.A.F. by the Bureau. Just as arrangements had been made to commence
41
work, the project was abandoned. Experiments were also carried out for the Imperial Chemical Industries (China) Limited on the value of "Gammexane" as an insecticide.
Notification of Malaria.
In September, 1945, notification of malaria was made compulsory for the first time, and an analysis of the complete year's figures are attached. 2424 cases were notified for 1946 for the whole Colony. During the year. 1825 positive slides were diagnosed in the Government Laboratories which leaves 597 caser diagnosed clinic- ally. It will be seen that the incidence of the disease fell progressively throughout the year.
In the early portion of the year, the high figures were probably due to relapses occurring amongst the heavily infected, newly returned population from rural China, and further from the local population who had suffered severely from the breakdown of malaria control under the Japancae. Normally, the highest incidence of malaria occurs in November and December. This year in these two months it was the lowest, proving that malaria control and 'bonifcation' were taking effect.
More difficult to account for is the extraordinarily high death-rate attributed to malaria compared with the notification rate. It may mean faulty diagnosis, or it may be a deliberate attempt to conceal other diseases such as typhoid. An enquiry into the circumstances of death from malaria in urgently required, and a question- naire is now being sent to practioners in cases of deaths ascribed to "malaria requesting particulars of history, laboratory confirmation, etc. If the high relative death-rate wore true, one might expect some black-water fever, whereas not one case was notified in the year. But quite a number of cases of cerebral malaria were reported in from the centre of the town/
Permanent Anti-malarial Work.
No new permanent anti-malarial work was done during the year, but much repair work on existing nullahs which had suffered four years neglect was under- taken. A large nullah a legacy of the Japanese occupation efrcumscribing the Airport, baa proved very difficult to deal with, in that, owing to its pour construction, It has been found inadvisable to take out the silt and vegetation for fear of weakening the walls. Meanwhile it is being oiled pending a discussion on the future of the Airport.
Mosquito Nuisances.
The Bureau undertook the investigation of 140 cases of mosquito nuisance on behalf of the Health Department in the year.
Maps.
Maps showing the disposition of our inspectorate, labour force, stores, and areas of control are attached.
Legislation.
A strong legislative policy in regard to larval control is of first importance. The growing by wet cultivation of certain crops has always been a dangerous source of mosquito breeding, and at the beginning of this year, a law probibiting the one of this method of agriculture was enacted. In spite of this low, this dangerous method of cultivation has, so far from diminishing, continued to spread, and now presents a real menace to the Air Port and Barracks. Firm legal action by the Crown Landa Department to enforce the conditions of their land permits, and education of culti- vators generally by the Agricultural Department to improve methods of growing crops to prevent mosquito breeding is urgently needed.
J. B. MACKIE, M.P, chis (Edin.), PP.H. (Liv), nra. (Liv.)
Malariologist..