. Animal parasites and human disease. Medical parasitology; Insects as carriers of disease. LOA WORM 309 tissue in and about the eyes, but may also be found creeping under the skin of fingers, breast, back, etc. A loa is said to travel at the rate of about an inch in two minutes, and to become especially active in the presence of direct warmth on the skin, as before a fire. The migration of the worms causes itching and a " creeping " sensation, and in some unexplained way gives rise to temporary swellings, from half an inch to four inches in diame- ter, known locally as " Calaba
. Animal parasites and human disease. Medical parasitology; Insects as carriers of disease. LOA WORM 309 tissue in and about the eyes, but may also be found creeping under the skin of fingers, breast, back, etc. A loa is said to travel at the rate of about an inch in two minutes, and to become especially active in the presence of direct warmth on the skin, as before a fire. The migration of the worms causes itching and a " creeping " sensation, and in some unexplained way gives rise to temporary swellings, from half an inch to four inches in diame- ter, known locally as " Calabar ; These swellings may shift their position an inch or more a day, and may disap- pear to reappear somewhere else. This relation of Loa to Cala- bar swellings has not been definitely proved but there is strong evidence for it. In one case Manson succeeded in finding great numbers of microfilariae of Loa in lymph taken from one of these swellings, a fact which gives color to Manson's hypothe- sis that the swellings might be due to the emission of larvae from the parent worm into the connective tissue. The larvae of the parasite (Fig. 124C), very closely resembling the microfilariae of F. bancrofti, occur in the blood in great numbers, but they have a periodicity di- rectly opposite to that of the latter species in that they swarm in the peripheral blood in the daytime and withdraw to the larger vessels at night. The living larvae of the two species cannot readily be dis- tinguished from each other in fresh blood, but in dried and stained preparations the dead organisms can easily be identified. The micro- filaria bancrofti are found lying in smooth graceful curves (Fig. 129A), while the microfilaria? loa die in ungraceful and irregular scrawl-like positions (Fig. 129B), with the tail nearly always sharply turned back (Fig. 129C). There is much evidence that the intermediate hosts of L. loa are mangrove flies of the genus Chrysops, which belong to the &&?#
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectmedical, bookyear1918
