During the last six months I have at intervals examined blood drawn from Miss H⸺ at various periods of day and night, but have never been able to discover the presence of any filariæ.
My patient has several times directed my attention to ill-defined swellings under the skin of the forearms a little above the wrists, over the dorsal surface of the radius, more marked generally in the right arm. The surface of the swellings was not quite uniform, but did not give one the idea of being produced by a coiled-up worm. The swellings measured about half an inch in diameter. They were not painful, but occasioned a feeling of stiffness when the arms were used. The swellings occurred at irregular intervals, and were generally most marked in the mornings. Cold had no influence in dispelling them; on the contrary, the application of cold water on one or two occasions seemed to bring the swellings forward.
My patient informs me that natives of Calabar, and others resident for a time there, are subject to such swellings in the forearms and wrists, to which the natives apply the term “Ndi töt,” or swelling. These swellings she has only suffered from since her return home.
I have further a correction to make in the history of my patient I previously submitted. It would appear that while she was most careful with regard to the purification of her drinking-water by boiling and filtering, she was for ten days prior to leaving Old Calabar so completely prostrated as to be unable to attend to any household matters, and the person who undertook her duties was unacquainted with the procedure employed for purifying the water. It might thus readily happen that she at that time partook of impure water containing embryo filariæ. As she had no symptoms of filaria till after her return home, this might explain their entrance into her system.
It is easy to understand how the embryo filariæ may enter the system, although their presence in impure water has not yet been demonstrated. And it is easy to conceive that, having entered the system from the alimentary canal, they may breed and bring forth a large crop of embryo parasites. But the chief difficulty consists in determining how these embryo filariæ escape from the bodies of those affected with the disease, and get deposited in the impure water and thus propagate the disease.
In the case of the Filaria sanguinis this is accomplished by the mosquito which constitutes the intermediate host; but as in the case of my patient, as well as in the case reported by Dr. Logan of Liverpool, careful examination of the blood failed to reveal the presence of embryo filariæ, some other system of propagation than that by blood-sucking insects must be looked for. Possibly the embryo parasites may be discharged along with some of the excreta from the body, and from faulty sanitary arrangements find their way into drinking-water. Whether this be so or not, future investigation will probably show.
Report on the structure of the female parasite (by Dr. Manson).—Female Filaria loa: length, 3·25 cm.; breadth, 0·5 mm.; ova at morula stage, 0·03 by 0·02 mm.; length of outstretched embryos in uterus, 0·25 mm.
As regards her general appearance, the female Filaria loa resembles the male parasite, only she is considerably larger and her tail is straight, tapers to a diameter of about 0·1 mm., and is then abruptly truncated. The mouth, the head, the stout muscular ring just posterior to the mouth, the stout longitudinal muscular bands, and the bosses on the integument resemble exactly those of the male worm. In consequence of the mutilation of the specimen it is impossible to say where the vagina opens, or where the anus is placed. The uterine tubes are stuffed with embryos at all stages of development. The more mature embryos resemble in size and shape those of F. nocturna and F. diurna, but in consequence of the method of mounting it is impossible to say if they are possessed of a sheath or not. If they are possessed of a sheath, I should say that they are practically indistinguishable from the parasites mentioned.
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