Prevalence of parasites, species composition and abundance of rodents and shrews in Ilemela District, Mwanza Region, Tanzania
Loading...
Date
2024-05
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Sokoine University of Agriculture
Abstract
Rodents and shrews are extremely diverse in their ecology and
lifestyles and can be found in almost every terrestrial habitat. The
diversity of rodents and shrews varies with vegetation type, habitat
and season. There are tremendous impacts attributed to rodents
and shrews which include but not limited to damaging field crops,
causing post-harvest losses, contaminating stored food and water
supplies. Nevertheless, they are reservoir of different parasites of
public health importance and play an important role in the
transmission and spreading of zoonotic diseases in Tanzania and
worldwide. Generally, this study aimed to determine rodents and
shrews species composition and prevalence of parasites, in Ilemela
District, Mwanza region, Tanzania.
Rodents and shrews were live-trapped using Sherman and modified
wire cages from Peridomestic, indoors and agricultural fields and
their morphological data were recorded for identification to the genus
and species level. Morphological data such as sex, weight, head-
body, tail, ear, and hind foot lengths were recorded. They were then
anaesthetized with diethyl ether, blood samples were collected
aseptically from heart, thin and thick smears were made for
haemoparasites identification and their ectoparasites were also
collected for identification purposes. The Gastro-Intestinal Tract
(GIT) was carefully removed and their contents were evaluated for
GIT parasites.
A total of 149 small mammals were captured and identified that
includes 144 rodents belonging to four species namely Mastomys
natalensis 66.4% (99/149), Mus .musculus 21.5% (32/149), Rattus
rattus 7.4% (11/149) and Aethomys spp 1.3% (2/149) and the rest
3.4% (4/149) were shrews belonging to Crocidura spp. The overall
prevalence of ectoparasites was 56.4% (84/149) and the following
ectoparasites were identified, Laelaps echininus 39.6% (59/149),
Polyplax spp. 4.0% (6/149), Xenopsylla cheopis 2.7% (4/149) and Heamaphysalis leachi 0.7% (1/149). The highest prevalence of
ectoparasites was recorded in M. natalensis at (67.7%). In context to
sex, males harbored more ectoparasites 59.0% than females.
Additionally, the study also found a prevalence of haemoparasite
was 35.5% (53/149) and the identified parasites namely, Anaplasma
spp 18.8% (28/149), Trypanosoma lewisi 0.7% (1/149), Plasmodium
spp. 1.3% (2/149). There were also two bacteria genus, bipolar
coccobacilli2.7% (4/149) and Bacillus spp 3.4% (5/149) identified.
Anaplasma spp was found in all of the infested rodent species and
its highest prevalence was recorded in M. musculus 34.4% (11/32)
followed by M. natalensis 27.3% (27/99). However, T. lewisi was
only found in Rattus rattus whereas none of the haemoparasite was
identified in Crocidura spp. The relative abundance of the captured
rodent’s species were Mastomys natalensis 99 (68.75%), Mus
musculus 32 (22.22%), Rattus rattus 11(7.63%) and Aethomys spp
2 (1.38%). Mastomys natalensis was widely distributed in all the
habitats and its highest abundance was recorded in agricultural
farms (83%, n=82/99). Mus.musculus (96.9%) and all R. rattus
(100%) exclusively captured from in-doors, while Aethomys spp 2
(1.3%) were only captured from the Peridomestic habitats. The study
found a significant association of the villages) with the captures (p <
0.01). In six of the villages selected for current study, M. natalensis
was the most prevalent and abundant species captured. The overall
prevalence of GIT parasites was 53.7% (80/149) and the following
parasites were recovered, (nematodes 80.5% (91/113), cestodes
14.2% (16/113), trematodes 0.9 (1/113) and protozoan oocysts 4.4%
(5/113). The recovered nematode parasites include; Trichuris spp
52.2% (59/113), Angiostrongylus spp 4.4% (5/113), Nippostrongylus
spp 6.2% (7/113), Strongyloides spp 13.3% (15/113), Capillaria spp
3.5% (4/113), Physaloptera spp 0.9% (1/113) and Syphacia obvelata
0.9% (1/113). The identified Cestode was Hymenolepis diminuta
14.2% (16/113) while in Trematode, only Echinostoma spp 0.9%
(1/113) was identified. Apart from worms also protozoan Oocyst
4.4% (5/113) were identified. Majority of the captured rodents were
infected with nematodes 65% (91/113) and the highest prevalence of GIT parasites was recorded in M. natalensis 64.6% (64/99). Trichuris
spp was found to be the most prevalent parasite in rodents. Among
the identified parasites, Hymenolepis diminuta, Angiostrongylus spp,
Capillaria spp and Syphacia obvelata are of public health
importance.
This study has revealed the presence of parasites of public health
and livestock importance in rodents and shrews and we recommend
for the control of rodents and shrews as well as screening of
human’s population to check for presence of the identified zoonotic
parasites reported in rodents and shrews.
Description
MSc Dissertation
Keywords
Rodents, Shrews, Ectoparasites, Gastrointestinal parasites, Species composition, Ilemela, Tanzania