Capillaria hepatica infection in wild rodents collected from the States of Kelantan, Selangor and Johore in Peninsular Malaysia since 1973 is reported. A total of 1,258 rodents consisting of 20 species of house, field and forest rats, and 7 species of squirrels were examined for the parasite and 17 species consisting of 111 murids and 1 flying squirrel were found infected. The house rat, Rattus norvegicus had the highest prevalence rate, followed by 3 species of field rats, R. tiomanicus, R. argentiventer and Bandicota indica. The prevalence of infection was low among forest rats with the exception of Lenothrix canus. Only 1 flying squirrel, Hylopetes spadiceus was found with the parasite. The prevalence of infection in relation to the host behaviour and habitats was discussed. C. hepatica appears to be widespread throughout Malaysia with a wide range of hosts among rodent species. Some new host records are presented herein.
A survey of the freshwater snails, Pila scutata and Bellamyia ingallsiana, as food consumed by the local population was carried out in Peninsular Malaysia. Of these two species the first is preferred; the sizes favoured are between 25--40 mm. Pila snails were found to be consumed by the three communities, viz. Malay, Chinese and Indian, in different ways. The various methods of preparing the snails for consumption are described. P. scutata is an intermediate host of the rat-lung worm, Angiostrongylus malaysiensis. As this worm presumably is the causative agent of human eosinophilic meningoencephalitis, the eating habits of the three races in consuming the snail in relation to the epidemiology of the disease was also discussed.
A survey of Angiostrongylus malaysiensis among wild rodent and molluscan hosts was made in the Tuaran Central Agricultural Research Station and within the vicinity of Tuaran, Sabah. Three of 19 Rattus rattus diardii, one of 2 R. exulans and one R. argentiventer were found naturally infected with the parasite. In this survey 56 of 382 molluscs comprising of Pila scutata, Achatina fulica and two species of land slugs, Laevicaulis alte and Microparmarion malayanus, were found naturally infected with the parasite. Samples of larvae from each of these molluscs were experimentally transferred to laboratory albino rats and adult worms consistent with A. malaysiensis were recovered. Comparison of the rat hosts and the molluscan intermediate hosts of the parasite in Peninsular Malaysia, Sarawak and Sabah was made, and the finding of A. malaysiensis in Tuaran is the first report of the parasite from Sabah. The distribution of the parasite throughout Malaysia is discussed. Observation on the human consumption of the freshwater snail, P. scutata, was made. Although the infection rate of this snail is low compared with other molluscan hosts examined. The importance of this mollusc as a potential source of human infection should not be overlooked. Hospital records for 1974 and 1975 were examined and clinical human angiostrongyliasis was rarely recorded in Sabah.
An immature Glossy Tree-Starling (Aplonis panayensis strigatus), also known as ‘burong perling’ in Malay, was captured in the vicinity of the Institute for Medical Research, Kuala Lumpur. It was found to harbour a small malaria parasite which showed the characteristics of the sub-genus Novyella (Corradetti et al, 1963) viz:
1. Trophozoites small with little cytoplasm, relatively large nuclear elements, the parasite usually applied to the host-cell nucleus.
2. Schizonts with usually less than eight merozoites. 3. Pigment small and difficult to see except in the schizonts and in the gametocytes where the pigment granules are large and usually clustered at one end.
4. The parasite rarely distorts the host erythrocyte. Unfortunately the bird died a few days later before detailed work on duration of the schizogonic cycle and experimental transmission could be done. The parasite has the following morphological features and most of the larger forms, asexual and sexual, assume the characteristic position proximal to the nucleus of the avian erythrocyte. Trophozoites: The earliest forms are ‘rings’ with a fairly marked vacuole. As the organism grows older, it produces a grain or two of pigment. The parasite at this stage tends to occupy a polar position in the host erythrocyte. Schizonts: The segmenting forms are usually attached to the pole end of the host-cell nucleus. The number of chromatin segments varies from 3 to 8, with a prevalent range of 4 to 6. The cytoplasm is scanty and pale with a prominent little mass of blackish-brown pigment or a close collection of granules. A rare mature schizont with 8 merozoites was seen in which the nucleus of the parasitised erythrocyte was displaced somewhat similar to figure 20 of Plate I portrayed in the original paper by Manwell (1935). Gametocytes: The sexual forms are often narrow and elongate, and are closely applied to the nucleus of the host erythrocyte. The outline of the parasite is frequently irregular. The cytoplasm is pale and vacuolated with coarse conspicuous granules of blackish-brown pigment usually collected at one end; sometimes either one or both ends curved around the host-cell nucleus. Although this parasite has some affinites to both P. nucleophiltim and P. hexamerium the lack of adequate study of the avian malarias of South-East Asia precludes even provisional identification of this parasite. On two occasions numerous gametocytes were seen in the peripheral blood of the bird and four species of laboratory-reared culicines (three indigenous to Malaya) were allowed to feed on it. Ten Andes togoi, 19 Culex sitiens and seven Culex fatigans were completely refractory to development of the parasite. Two of 17 Aedes aegypti had a single small oocyst each; both oocysts appeared to be degenerating. A Giemsa-stained thin blood film together with drawings made from the microscope showing the different forms of the parasite were demonstrated. REFERENCES
Corradetti, A., Garnham, P. C. & Laird, M. (i963). Parassitologia, 5, 1-4.
Manwell, R. D. (l935). Amer. J. Trop. Med 15, 265-283.
...(1938). Ibid., 18, 565-575