26
STUDIES ON NASAL SCHISTOSOMIASIS
[Vol. XXIV, Part I,
miles, were examined and 32 (47 per cent), 65 (79.2 per cent) and 22 (78.5 per cent)
respectively were found positive for fasciola infection. Some of the animals, es-
pecially buffaloes, had received carbon tetrachloride treatment recently. The
higher incidence of infection in buffaloes and goats is interesting. Paramphistome
eggs were very often found in association with this infection in buffaloes. Among
other helminthic infections met with during the course of these examinations may
be mentioned Trichostrongylosis, Oesophagostomiasis, Trichuriasis and Ascariasis
(particularly in young calves). Faecal samples from two elephants (commonly
found in the locality) were also examined; one of them showed fasciola eggs (pro-
bably Fasciola jacksoni).
Two adult cattle and ten goats were examined post-mortem for adult worms,
but none could be recovered from the former while seven (79 per cent) of the latter
yielded about 20 worms, varying from two to seven from each in their different
stages of development. No opportunity was available to examine any buffalo post-
mortem in this locality.
A tour in the surrounding areas to study the physical features of the country
and also the molluscan fauna of the locality revealed what has been discussed earlier
in respect of the most favoured habitats of the snails. Snails of both Limnaeid
and Planorbid groups were found in abundance in water-logged marshy grounds,
locally called 'Chaurs', infested with vegetation grazed by animals. A few of these
snails, about 100, were tested for natural infection and two Planorbis only were found
to discharge some leptocercous distome cercariae, which were preserved for specific
study. On examination they were found to be two different cercariae. One lot
was xiphidic-cercariae corresponding, but for slight greater dimensions, to 'cellulosa'
group of Sewell [1922] and resembling Cercariae indicae LVII. Sewell got these
cercariae from Digoniostoma cerameopoma in a tank in the Indian Museum,Calcutta.
Thus, Planorbis exustus becomes another host of this cercaria and the change of
host might as well account for dimensional variations. The other lot of cercariae
had a long tail without fin-folds and collar-spines. These corresponded to 'Agilis'
group of Sewell [1922] but differed from his only form of the group, Cercariae indicae
XVI, which he had recovered from Amnicola travancorica in the Wynaad (South
India).
All those apparently non-infected snails were later dissected out for the develop-
ing carcarial stages, but only one Limnaea (L. auricularia race rufescens) was found
to be infected with leptocercous distome cercariae that did not come out when being
tested in tube containing fresh well-water. The cercariae resembled fasciola, but no
definite opinion can be given as to their identity, as their morphology could not be
studied in detail in the field. Thus, no conclusive evidence could be obtained re-
garding the potential molluscan intermediary of the parasite, although Limnaea
auricularia race rufescens were found abundantly and widely spread.
Saharsa area
Forty-eight faecal samples (18 from cattle, 23 from buffaloes and seven from
goats) were examined for fasciola ova and 10 (55.5 per cent), 19 (82.6 per cent) and
five (71.4 per cent) were respectively found positive. No opportunity was afforded
to examine some animals post-mortem. There was no evidence of any anthelmintic