DIS TBI BUTTON AND RELATIVE ABUNDANCE OP SNAIL VECTORS OF SCHISTOSOMIASIS IN SOME DAMS IN AND AROUND ZARIA, NORTHERN NIGERIA
DIS TBI BUTTON AND RELATIVE ABUNDANCE OP SNAIL VECTORS OF SCHISTOSOMIASIS IN SOME DAMS IN AND AROUND ZARIA, NORTHERN NIGERIA
No Thumbnail Available
Date
1988-08
Authors
Hassan, Peter Jacob
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Satedams (Kubanni, Makwaye, Maska, Kangimi, Maigana, zaria
Birnin Gwari), three ponds in Zaria City and a stream in
Samaru village were surveyed from June, 1986 - May, 1987 to
determine the distribution of snail vectors of human
schistosomiasis.
Three species of these snails were observed in the area
namely, Bulinus (Physopsis) globosus (Morelet) Bulinus forskalii
and Biomphalaria pfifferi (Krauas) B. glojbiasjis is a vector
of urinary schistosomiasis, the parasite being Schistosoma
haematobium. B. forskalii is a suspected alternative host
of S. haematobium while Biomphalaria pfeifferi is a vector
of intestinal schistosomiasis, the parasite being S. mansoni.
The abundance of these snail vectors varied with the season
and among habitats. There were more snails at the beginning
of the dry season than any other time of the year. There were
also more snails in the ponds than any other site of collection.
Of the three species of snails collected B. globosus had
the highest number during the period in which the research was
conducted, it was also the most wide spread snail species, and
co-existed with B. forakaiii. B. pfeifferi was least
represent both in terms of numbers and distribution in the sites.
All through the duration of the work juvenile snails were
observed to co-exist with adults, and occurred throughout the
time of research work. Their number, however, depended on
(Jd)
the number of adults in a particular habitat. This, therefore,
strongly suggested that reproductive activities of these snails
were going on throughout the year.
Observations made on the three snails species for the
presence of furoocercous cercariae showed that the two forms of
Bchistosomiasis were endemic in the area as all the three species
shedded furoocercous cercariae. However, it was noted that
urinary schistosomiasis was more prevalent than the intestinal
form because the greatest number of furcoceroous cercariae were
produced by Bulinus globosus which is the vector. Snail
examinations further pointed to the fact that snail infestation
by the furoocercous cercariae was throughout the year, and not
seasonal.
The Principal factors which seem to determine the
distribution of these snails were availability of water its
nature, presence of aquatic vegetation and human-water contact
degree.
Kubanni dam was observed to be filled by late May or early
June, thereafter, water starts spilling over at the spillway
while Makwaye dam was not filled until late July or early August.
Makwaye dam showed highest snail densities dominated by
B. globosus. A contributing factor might be the presence
of better vegetation growth in the Makwaye dam. Observations
also showed that snails decrease in their number with distance
from the town (Zaria).
Description
A thesis submitted in partial fulfillment of
the requirements for the award of the degree
of Master of Science (M.Sc.) in Zoology.
DEPARTMENT OP BIOLOGICAL SCIENCES
FACULTY OP SCIENCE
AHMADU 3ELL0 UNIVERSITY
ZARIA
AUGUST, 1988
Keywords
DISTRIBUTION., RELATIVE,, ABUNDANCE,, SNAIL,, VECTORS,, SCHISTOSOMIASIS,, DAMS,, ZARIA,, NORTHERN,, NIGERIA.