Veterinary Parasitology

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Browsing Veterinary Parasitology by Author "Dr. Ashenafi, Hagos"

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    Pathological and Seroprevalence Studies on infectious Bursal Disease in Chickens In and Around Bahir Dar, North west, Ethiopia
    (Addis Ababauniversity, 2015-06) Teshager, Natnael; Dr. Ashenafi, Hagos
    A cross sectional study was conducted from January 2015 to May 2015 to characterize the pathological changes and to determine seroprevalence of IBD and its associated risk factors in chickens in and around Bahir Dar. The clinical signs observed in IBD infected chickens were whitish diarrhea mixed with blood, ruffled feather, and massive death within short period. The necropsy findings were petichial hemorrhage in bursa of fabricius, kidney, thymus, spleen, thigh and pectoral muscles. Bursa of fabricius became edematous in serosa and mucosal part, whitish-creamy and atrophied as the course of the disease progressed. Kidney became pale and ureter was turgid with urate in a numbers of cases. The histopathological changes in this study revealed that edema of bursa of fabricius, formation of cystic follicles, depletion of lymphocytes, fibrosis and follicular architecture lost. Severe, moderate and mild lesion score were observed in bursa of fabricius. Infiltrations of heterophils were noted both in lymphoid and non lymphoid tissues. Depletion of lymphoid cell in germinal center of spleen and total depletion of lymphoid cells were encountered in thymus gland. The kidney tubules were filled by exudates and necrotized cuboidal cells. Sera collected from a total of 320 chickens were subjected to IELISA test and disclosed an overall prevalence of 51.56% (CI: 45.95 – 57.14) in study area. The seroprevalence of IBD among chickens showed a statistically significant difference (P<0.05) among study sites namely Andassa (72.73%), Gombat (50%), Wonjeta (47.69%), Meshenty (44.44%) and Bahir Dar (42.42%). The susceptibility of chickens to IBDV revealed a statistically significant difference (P<0.05) among different breeds where Koekoek was found more prone to IBD infection with seroprevalence of 67.11% followed by Bovans brown (57.69%), local breeds (48.31%), and Bovans white (40.28%). The seroprevalence of IBD was also significantly associated (P<0.05) with the age of chickens and among farm systems. These studies clearly indicated that IBD infection is a common and wide spread problem affecting a number of chicken breeds under different management systems and hence an urgent control intervention should be in place. Keywords: Age, Bahir Dar, Breed, Chickens, Histopathology, Lesions, Seroprevalence, sex
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    Toxoplasma Gondii in Selected sites of Central Ethiopia: Seroprevalence, Risk Factors and Bioassay in Pigs
    (Addis Ababauniversity, 2014-06) Megersa, Mulisa; Dr. Ashenafi, Hagos
    The objectives of this study were to estimate the sero-prevalence of Toxoplasma gondii infection, assess potential risk factors and isolate viable T. gondii tissue cyst in mice from hearts of seropositive pigs. A cross-sectional study was used to collect blood samples from a total of 557 pigs in Central Ethiopia. A systematic random sampling technique was used for blood sample collection. For bioassay 5 mice were used per pig sample. Modified Agglutination Test (MAT) was used to test sera of pigs and mice. A questionnaire survey was made to assess potential risk factors and knowledge of farm attendants about toxoplasmosis. For investigation of risk factors questionnaire and sera samples from 402 pigs were considered. Results of the questionnaire survey indicated that most of the farm attendants had no knowledge of health risk of cats either to human or animals. Absence of rodent control, neonatal mortality and history of abortion was found among herds of the study farms. The overall estimated seroprevalence was (32.7%; 95% confidence interval (CI): 0.288-0.366). Multivariable logistic regression analysis showed that extensively managed pigs are nearly twice (adjusted odds ratio [aOR]:=1.91, 95% CI: 1.01, 3.63) at higher risk of acquiring toxoplasmosis than intensively managed pigs and pigs supplied with feed containing additional animal byproduct had four times (OR=3.84, 95% CI: 2.01, 7.36) higher risk of acquiring T. gondii infection. Viable T. gondii was isolated from 48% (24/50) of the seropositive pigs. Most isolates (91.7%, 22/24) are avirulent for mice. One isolate from Bishoftu which killed four mice on day 28 and 29 postinoculation suggesting intermediate virulence. A perfect agreement was observed between MAT and microscopic cyst detection (Kappa =0.85) used as diagnostic method on mice.This is the first report of detection of T. gondii antibodies and isolation of viable T. gondii from pigs in Ethiopia. The high seroprevalence and isolation rate indicate that T. gondii parasite is widespread in the study areas and pigs could serve as an important source of T. gondii infection for pork people. Further epidemiological studies are essential for designing appropriate prevention and control strategies in pigs. Keywords: T. gondii, sero-epidemiology, bioassay, pig, mice, Central Ethiopia