12 STUDIES ON NASAL SCHISTOSOMIASIS [Vol. XXIV, Part I,
Mr. G. L. Wilkins of the Mollusca section of the British. Museum (Natural History),
by comparing with the type specimens and referring to literature on the subject.
All the forms, thus collected and identified, are catalogued in Appendix B with a
Plate of illustrations.
NASAL SCHISTOSOMIASIS (NASALGRANULOMA)
Schistosoma nasale Rao, 1933
Malkani [1932] announced both at a public lecture in Patna (Bihar—India)
and in a communication published in the Veterinary Record that Nasalgranuloma
in cattle was a helminthic infection caused by a parasite of schistosome group.
Soon after this, Datta [1932] published details of his researches in this connection
establishing schistosomic etiology of the disease and indicated that the causal
schistosome was probably S. spindale Montgomerie, 1906. Prior to this, it was
believed that the condition was Rhinosporidiasis (caused by a fungus). Bhalerao
[1932] studied its helminthological aspect and after examining a number of adult
parasites, both males and females, came to the conclusion that they were identical
with S. spindale. Rao [1933] demonstrated and subsequently [1934] established
that the schistosome species, responsible for causing nasalgranuloma, was quite
different from S. spindale, which produces intestinal schistosomiasis. He named
the nasal schistosome as Schistosoma nasalis n. sp. In conformity with the rules
for zoological nomenclature for Latin names, it is now called Schistosoma nasale.
As nothing much is known in detail regarding the bionomics and pathogeni-
city of this parasite, an effort was made to establish this schistosome, reported so
far from India only, in laboratory animals in London. This was done with a view
to studying their behaviour in animals outside endemic areas. Living infective
material from different areas of nasal schistosomiasis were despatched to London
by air-mail under different biological techniques (vide Appendix A)* to ensure that
they would remain alive in transit, but the results were disappointing. Only two
Planorbis snails arrived alive, but they were found to be non-infected. Dr P. L.
LeRoux was, however, good enough to take pains to breed these snails successfully
in the laboratory, thereby establishing the Indian Planorbis there for experimental
work.
METHODS EMPLOYED IN THE SURVEY
In the present work an effort was made to ascertain the incidence of the disease
in the locality by rapid examination of infective materials from susceptible animals.
Whenever and wherever opportunities were available, autopsies were conducted to
study the bionomics and pathogenicity of the parasite. The material (nasal dis-
charge) was examined by the ordinary direct preparation method of putting some
of the discharge between two clean glass slides or using a large cover-slip instead of
the top slide, and examining it under low-power objective (1/ 3) of the microscope.
One has to be careful in taking the specimen from the ulcerated area of the nasal
septum, as extraneous discharge from the upper respiratory passage may not show
any eggs of the parasite at all. The samples thus examined showed the typical
boomerang-shaped eggs of S. nasale, although variations were not unusual, depend-
ing largely upon how the egg was lying in the field under focus. These variations
* Appendices on pp 32 and 33.