[Reports, 1914-19 / Australian Institute of Tropical Medicine].

  • Australian Institute of Tropial Medicine
Date:
1914-1920
Catalogue details

Licence: In copyright

Credit: [Reports, 1914-19 / Australian Institute of Tropical Medicine]. Source: Wellcome Collection.

Provider: This material has been provided by London School of Hygiene & Tropical Medicine Library & Archives Service. The original may be consulted at London School of Hygiene & Tropical Medicine Library & Archives Service.

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    Other moisture-absorbing substances, such as potassium acetate and calcium chloride, were tried, but although their effect is greater than common salt, they are not substances which could be readily employed. Common salt in solutions of varying strength was em-ployed. Even with a strong (6 per cent.) solution, it was found that severareggs still remained alive and capable of hatching out for as long as six days. Using a 2 per cent, solution, larva; were hatched out nine days later. From this it is evident that a continued application of a strong solution of salt for at least a week is necessary to make certain of destroying all the eggs in the infective material. Work was continued on worm-]iodules in cattle. Experiments were made to ascertain the manner in which the larvae make their escape from the nodules, and the rate at which they do so. The investigations were conducted on nodules excised from the carcasses of slaughtered cattle. They were immersed in water and other fluids at different tempera- tures. Examination of the fluid at intervals showed the presence of larvso which had escaped from the nodules. In the course of the experiments, some of the nodules were fixed, cut into serial sections, and a detailed examination made of the sections. The results of this work indicate that the larvte make their escape from the nodules fairly readily and in considerable numbers. It would appear that a certain number of larva? are almost always present in the capsule of the nodule, and that a few of them are continually making their escape into the surrounding tissues. In the case of some nodules the number of migrating larvae was very large (several thousands in one instance), but the conditions which determine such an increase have not been ascertained. Examinations of the sections revealed the fact that the migrating larvae tend, though not constantly, to be arranged in concentric zones, and are almost invariably found in the denser parts of the capsules. They apparently make their way through the looser tissue with great rapidity. A detailed account of this work is almost ready for publication. Examination of local animals for parasitic worms has been continued. Over 50 animals have been dealt with, and about half of them have been found infected with worms. Investigation of these parasites has been proceeded with, and many interesting forms have been discovered. A first report on them was published in January of this year, a second report is in the press and will appear shortly, while a third is nearly ready for publication. Material from human cases infected with parasitic worms has been submitted to me for examination on thirteen occasions. These have proved to be three cases of infection with tape-worms {TceniarJiynclius saginatus), six cases of infection with hook- worm alone {Ankylostoma and Necator), three of the hook-worms along with thread- worms {Oxyuris), and one of the hook-worms and whip-worms {TricJiuris). In some cases both varieties of hook-worms were present together, but in four cases only Ankylostoma was found and in one only the American variety {Necator americanus). Over 1,000 hook-worms were collected, including 298 Ankylostoma and 735 Necator. Thread-worms and whip-worms were not numerous. In most cases infection with these worms was probably acquired in Australia, but in one case of tape-worm it would appear as if the patient had become infected before arrival in this country. A research on the bacteriology of mosquitoes was commenced. 135 mosquitoes have been examined, comprising the following seven varieties :— Stegomyia fasciata 51, Culicelsa vigilax 57, Culicelsa annulirostris 4, Culex fatigans 15, Culex tigripes 1, Mucidus alternans 4, and Nyssorhynchus annulipes 3. Most of these were obtained from the living rooms of local houses, but a few were captured in tho vicinity of the Institute. In only two of these varieties, namely, Stegomyia fascia'a and Cv.licelsa vigilax, were any bacteria found, and in these only on few occasions, five times in Stegomyia and four in Culicelsa. The majority of the mosquitoes examined were females, but several males were included. Li the case of the females a consider- able number contained blood in their crop.