M.
ANANT
NARAYAN
RAO
195
pharynx, living with his wife and family for a period of over eight years without
infecting any one of them. The present author has repeatedly failed to trans-
mit the disease directly, with the spores from the lesions of diseased bovines,
to healthy bovines or laboratory animals. Hence it would appear that in
nature direct infection with large spores from the lesion does not take place.
If the discharged spores obtained from the parasitic stage of Rhinosporidium
are not infective, the only other alternative is to admit the existence of a sap-
rophytic form of the fungus whose spores are infective.
It would be interesting to examine this question of the existence of Rhinos¬
poridium outside the animal body as a saprophyte. An analysis of the pub-
lished reports on the disease by workers in India,—notably Wright [1922],
Kurup [1931], Noronha [1933], Allen and Dave [1936] and Mandlik [1937]—
shows that there is a close relationship between rhinosporidiosis and agricul-
ture. A very large number of cases reported, belong to the agricultural class
of people in India. Allen and Dave say that the condition exists in the agri-
culturists even outside India. The present author found that over 95 per cent
of the bovines affected were bullocks used for agricultural operations, chiefly
ploughing. This finding of the author supports the view that rhinosporidiosis
is primarily an occupational disease. Secondly it seems clear that the infec-
tion is carried either by (a) dust or by (b) water.
(a) Infection dust-borne.—In the recorded cases of rhinosporidiosis in
human beings over 90 per cent had lesions in the nose. In the series recorded
by Allen and Dave, 68.3 per cent were agriculturists and their children, of
which over 97 per cent had the lesions in the nose. Among bovines or equines
recorded, 100 per cent had the lesions in the nose. The enormous percentage
of infection in the nose in men and animals connected with agriculture at once
suggests that the infective material is dust-borne and that it should have
existed on the fields.
When ploughing fields, plenty of dust is raised and the man behind the
plough gets more of it than the animals in front which draw the plough.
Therefore such men will be exposed to the infective material much more than
the bullocks and this is supported by the records which show that the incidence
in man is very much higher than in bullocks. Women and cows, seldom if at
all, take part in ploughing lands and the incidence in them is negligible.
Hence it seems reasonable to suggest that the common causal factor of infec-
tion is on the fields and is raised with the dust while ploughing and is inhaled.
Perhaps, therefore, the infection is a nasal condition than of any other tissue.
It is possible that infective material reaches the fields through manure in which
a variety of fungi grow. Cattle swallow their nasal discharge, and with it
a large number of spores from nasal lesions if present. These spores pass out
with their faeces in the same way as the other spores of fungi pass out when
they are ingested along with food or fodder. Most of such faeces of the dis-
eased animals are thrown on the manure heap and some of the spores of Rhinos¬
poridium in them are likely to germinate into saprophytic fungus, fructify and
liberate spores. If such manure is thrown on the fields, there is every chance
of those spores getting inhaled with the dust while ploughing. Such spores