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STUDIES ON NASAL SCHISTOSOMIASIS
[Vol. XXIV, Part I,
APPENDIX A
Methods employed for despatching living Schistosoma nasale eggs
1. Thick glutinous, blood-tinged nasal discharge, obtained by pressing the nasal
polypi with the thumb, was collected in clean sterile petri dishes from infected cattle
from different areas. While examining the samples microscopically for confirmation,
it was invariably found that some of the eggs had already hatched out and the
miracidia could be seen swimming about; others had miracidia ready to hatch
within the egg-shell. This is, however, not unusual, as the schistosome eggs take
some time (some days in some cases) to pass through the surrounding host-tissues to
come to the exterior and so by the time they are finally discharged most of them are
ready to hatch.
Since quite a number of eggs were still immature, an attempt was made to des-
patch them alive to London by air for experimental work. The discharge was
transferred to a piece of filter-paper (sometimes ordinary blotting paper was used),
damped in normal saline, which was then wrapped up and put in a small glass tube.
The tube was plugged with damp clean cotton wool (damped in normal saline)
and corked tightly. Three or four such tubes, containing samples from different
cases in a locality, were packed in small wooden cases, specially designed for the
purpose.
2. Employing the same technique as above, an alternative medium was used
to soak the filter-paper or the cotton plug with crystalline penicillin solution in vary-
ing concentrations, ranging from 12,500 to 100,000 (12,500, 25,000, 50,000 and
100,000) units.
Results. Owing to ready hatchability of these eggs (for the reasons advanced
above) even within the transit-period of air-mail, usually 4 or 5 days, the methods
were not successful. Some controls were kept under the same condition in local
atmospheric temperature, which, when examined at subsequent intervals, revealed
no trace of life in the egg-shell after about 48 hours. Most of them had already hatched
out within 24 hours.
Methods employed for despatching living Fasciola and Paramphistome eggs
1. Living worms (both Fasciola and Paramphistomum) were collected from
freshly killed animals and placed in a beaker or petri dish containing normal saline.
Each worm was soon after transferred to a clean sterile glass pan (watch glass)
containing a few drops of filtered water. The intra-uterine eggs were then dissected
out with a sharp pointed sterile scalpel, making a transverse incision on the ventral
side of the worm just below the genital opening and the eggs were squeezed out from
both ends of the uterus with the blunt edge of the scalpel. This yielded hundreds of
eggs which were then transferred to a piece of filter-paper smeared with fine faecal
culture (the faecal culture was made by emulsifying some fresh faeces, obtained from
the same host or at least the same species of animal from which the worms were
collected, with filtered water and straining off the coarse debris and filtering off
the liquid). The paper with the eggs was then wrapped up and put in a glass tube
which was plugged with damp cotton wool in order to prevent desiccation. These
tubes were packed and despatched in the usual small wooden sample boxes.