The Animal Parasites of ManFantham, Harold Benjamin
Science
The Animal Parasites of Man
Fantham, Harold Benjamin
Medical parasitology
Macfie has recently (August, 1913) described a human trypanosome
from the Eket district of Southern Nigeria. It is common in young
people. The disease produced does not seem to be of a virulent type
in Nigeria, and does not occur in epidemic form. In the early stages
the glands of the neck are enlarged. In the later stages--cases of
which are rarer--lethargy appears. The parasite is a polymorphic
trypanosome, morphologically almost indistinguishable from _T.
gambiense_, though it may be slightly shorter. Macfie recorded the
occurrence in his preparations of a few trypanosomes appearing to have
a flagellum free during their whole length. Some of the parasites,
as seen in a sub-inoculated guinea-pig, are very small (8 µ long).
Other trypanosomes have their nuclei displaced somewhat anteriorly.
This parasite may only be a variety of _T. gambiense_. The parasite is
perhaps spread by _Glossina tachinoides_.
[66] _Annals Trop. Med. and Parasitol._, vii, p. 339; viii, p. 379.
*Trypanosoma rhodesiense*, Stephens and Fantham, 1910.
The parasite was found in the blood of a young Englishman who had
contracted sleeping sickness in the Luangwa Valley, North-eastern
Rhodesia, in the autumn of 1909. The patient had never been in an area
infested with _Glossina palpalis_.
(1) _Morphology._--The morphology of the parasite in man and
sub-inoculated rats was studied by Stephens and Fantham in 1910.[67]
They pointed out a morphological peculiarity in the presence of certain
trypanosomes with posterior nuclei in sub-inoculated animals, that is,
parasites in which the nucleus (trophonucleus) was situated towards
the posterior or aflagellar end, close up to or even beyond the
blepharoplast or kinetic nucleus (fig. 31, _4_, _5_). When the nucleus
was beside the blepharoplast, the former was seen to be kidney-shaped
(fig. 31, _4_). The posterior nuclear forms were of the stout and
stumpy variety, and about 6 per cent. of the stumpy forms were found to
have their nuclei displaced from the centre. The anterior or flagellar
end of these trypanosomes often contained chromatoid granules. _T.
rhodesiense_ varies in length from 12 µ to 39 µ[68]; short stumpy forms
vary from 13 µ to 21 µ, intermediate forms from 21 µ to 24 µ, and long,
slender forms from 25 µ onwards. The average length is 24·1 µ.
[67] _Proc. Roy. Soc._, B, lxxxiii, p. 28.
[68] Stephens and Fantham (1912–13), _Proc. Roy. Soc._, B, lxxxv,
p. 223, and _Annals Trop. Med. and Parasitol._, vii, p. 27.
[Illustration: FIG. 31.--_Trypanosoma rhodesiense._ 1, Long narrow
form; 2–4, nucleus passing to posterior (aflagellar) end; 5, nucleus
quite posterior. × 1,800. (After Stephens and Fantham.)]
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