ANTHROPOLOGISTS are again indebted to Mr. Ling Roth for presenting to them, in a convenient form, the results of wide reading and diligent compilation. It is by such well-directed enthusiasm that the labours of the student are materially lightened; for not only has the author, in this instance, marshalled a portentous array of accurately acknowledged quotations, but he has sedulously collected illustrations of objects preserved m numerous museums and private collections, in order to fully illustrate the descriptions that he quotes.
A general survey has been made of tuberculosis in the Jesselton – Tauran area. Climatical, living, and occupational conditions tend to favour the spread and advancement of the disease. The death rate is high, but has been influenced by conditions attributable to the war. The native population, due to their mode of life, succumbs more easily to the disease that do the Chinese. Cases are usually seen in the late stages, mainly due to ignorance.
A first experiment on malaria control in the interior of Borneo by spraying with residual insecticides is described. The work was carried out in the isolated, sparsely populated valleys of the Baram River and its tributary, the Tinjar, in northern Sarawak. The experimental area was divided into three parts: a DDT test area, where a 75% suspension of wettable powder was applied at the rate of 2 g of DDT per m(2) of surface; a BHC test area, where a 50% suspension of wettable powder was applied at the rate of 0.10 g of gamma isomer per m(2); and a check area.Entomological investigations made before the spraying operations were started showed that Anopheles leucosphyrus Dönitz, 1901 was the main malaria vector in both the test and the check areas. Out of a total of 7568 A. leucosphyrus dissected, 30 gland infections were detected-a sporozoite-rate of 0.40%. A. barbirostris was found to be a secondary vector throughout the experimental area.THE RESULTS OF INSECTICIDE SPRAYING WERE SATISFACTORY: in the DDT test area, the spleen-rate fell from 51.8% to 25.1%, and the parasite-rate from 35.6% to 1.6%, in 21 months, and a similar reduction in the rates was observed in the BHC test area. In the check area, the spleen- and parasite-rates rose during the period of observations. It is considered that if such a degree of control can be obtained in 21 months, complete eradication can be expected in the near future.Although BHC spraying proved effective, the fact that it has to be repeated every three months makes it impracticable in the interior of Sarawak, where communications are very poor and difficulties of transport very great. DDT spraying, which need only be done twice a year, is therefore to be preferred. The cost of the DDT operations-US$ 0.45 per person protected per year-is comparatively high, owing to the difficulty of communications and to the necessity for spraying not only the village "longhouses", but also the temporary shelters which the semi-nomadic people in the interior of Sarawak build each year in the rice-fields.
SIR,-I was glad to read a letter from Dr. Copeland (Dec. 6), a pioneer in bringing medical treatment to the Muruts of North Borneo.1 I feel that something should be said about the present malaria situation there. McArthur's control measures for the vector " Anopheles leucosphyrus " (now A. balabacensis), were in fact resumed by him under the new post-war Government. Clearing the undergrowth around seepages was tried during 1949-52, and showed some reduction in vector breeding and spleen-rates.2 However, more recent surveys have shown that McArthur's experimental villages no longer show any malariometric advantage over comparison villages, despite his hopes for the relative permanence of his methods. It was decided by the GovemmentjW.H.O.jUNlcEF Malaria Project to use house spraying with residual insecticide, which had proved highly effective in Sarawak against the virtually identical A. leucosphyrus. For Dr. Copeland's information, these mosquitoes do rest on walls during the night for periods sufficiently long to make them susceptible to effective attack by residual insecticides. It has been shown during the past three years that residual insecticides produce a very great decrease in the density of the vector. On Labuan Island house-spraying alone has been successful in interrupting transmission, and when combined with antimalarial drugs it has been shown capable of controlling transmission even in the most difficult parts of the interior. The complete eradication of malaria from British North Borneo now appears to be an attainable goal.