Veterinary Parasitology

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Anthelmintic utilization practices in Ada’a district and in vitro anthelmintics efficacy study against Haemonchus.contortus and Trichostrongylus.columbriformis in Oromia, Ethiopia
(2020-06) GEBEYEHU, ALKADIR; Dr. Getachew Terefe, Dr. Bersissa Kumsa
The present study was conducted to assess anthelmintic (AH) utilization practices in Ada’a District of East Showa zone and evaluate the efficacy of commonly used anthelmintic classes of different brands collected from local markets A structured questionnaire survey was undertaken with 100 respondents farmers owning sheep and/or goats. For the Ah efficacy study, four drugs of different brands (Albendazole (ABZ) for egg hatch test, levamisole (LEV) and ivermectin (IVM) for larval motility test, and tetramisole (TMZ) for adult motility test) were investigated against local isolate of Haemonchus.contortus and Trichostrongylus columbriformis. ABZ and LEV brands originated from China (CN), East Africa (EA) and India (IN), Ivermectin from CN, IN and Uruguay (UG), whereas Tetramisole was from CN and IN. Serial dilutions of the drugs were made to achieve concentrations of 1.0, 0.5, 0.25, 0.125, and 0.0625μg/ml. g/ml. To undertake egg hatch test 100 eggs/well of H. contortus or T. colubriformis were incubated with the drugs at 270C for 48 hours. Larval motility test was done with 50L3 of H. contortus or T. colubriformis mixed with the drug of choice and incubated at 25 0C for 24hrs after which motile and nonmotile worms were counted. Similarly, the adult motility test was done with 15 adult H. contortus/well mixed with the test AH and incubated at 370c for 10 hours. All tests were done in triplicates and the median values were taken. Control wells contained eggs, L3 or adult worms with distilled water. The findings show that: a) the questionnaire survey indicated ivermectin was the most commonly used drug (39 %) followed by albendazole (36 %), tetramisole (17 %) and levamisole (8%), b) in the in vitro assays, all tested anthelmintics brands showed concentrationdependent responses on eggs, larvae and adult parasites; c) in egg hatch test on T.colubriformis eggs, CN and IN brands of albendazole performed >50% egg hatch inhibition at all drug concentrations; d) the EC50 for inhibition of T.colubriformis egg hatching was 2.375μg, 0.087μg and 1.199μg respectively for EA, CN and IN brands. The EC50 against H.contortus eggs was 0.504μg, 0.017μg and 1.886μg respectively for EA, CN and IN brands; e) East Africa brand of levamisole was more effective at reducing H.contortus larval motility than Indian brand (92% and 76% respectively) at 0.5μg while it is better at 0.5μg, 0.25μg and 0.125μg against T. colubriformis (P<0.05). The EC50 for inhibition of motility of T.colubriformis L3 by levamisole was 0.057μg and 4.028μg respectively for EA and IN brands suggesting a much better performance of EA brand over the Indian brand. The EC50 of levamisole against H.contortus L3 XIII was 0.058μg and 0.048μg respectively for EA and IN brands; f) the three brands of ivermectin at all concentrations tested had similar efficacy against motility of H. contortus L3. The linear regression for concentration-response curve indicates that the EC50 for inhibition of motility of T.colubriformis L3 by ivermectin was 0.073μg, 0.178μg and 0.040μg respectively for CN, UG and IN brands suggesting a lower performance of the Uruguay brand compared to the others. Similarly, the EC50 of ivermectin against H.contortus L3 was 0.025μg, 5.040μg and 3.061μg respectively for China, Uruguay India brands; g) in the adult motility test, both China and India brands of tetramisole have performed similarly against H. contortus. However, the EC50 was 0.134μg and 5.576μg respectively for CN and IN brands suggesting a marginal performance of the former and a much lower efficacy of the latter brand. In conclusion, excepting for few cases, ABZ, IVM and TMZ brands from china origin are more effective against eggs, L3 and adults of the parasites concerned. On the other hand, LEV from East Africa Company is proven effective against L3 of both parasites whereas LEV and IVM from Indian origin are effective only against L3 of one species at acceptable concentration. Therefore, while recommending anthelmintics of choice such variations must be taken in to account.
Bacteriological isolation and antimicrobial resistance profiles of Escherichia coli and Salmonella isolates, and survey on antimicrobial use and vaccine management in poultry, Central Ethiopia
(Addis Abeba University, 2024) Belayneh Seifu; Hika Waktole; Debebe Ashenafi
Escherichia coli and Salmonella are prominent bacterial pathogens responsible for avian Colibacillosis and Fowl typhoid in poultry productions, respectively. However, there is a paucity of comprehensive data regarding their prevalence and resistance to antimicrobials. This cross-sectional study was carried out between November 2023 and May 2024 in Central Ethiopia, aimed to determine the prevalence, patterns of antimicrobial resistance, and possible risk factors contributing to the development of resistance. A total of 313 swab samples were collected from randomly selected poultry farms, alongside with a structured questionnaire survey. The bacteriological examination revealed an overall prevalence of 30.35% Escherichia coli and 3.83% Salmonella. The highest rate of isolation for Salmonella was observed in Bishoftu (7.40%) and was absent in Addis Ababa and Mojo, while the prevalence of Escherichia coli varied significantly across the study sites, which found highest in Adama (41.26%) and lowest in Mojo (13.79%). Tissue swabs emerged as the primary carriers of both Salmonella (7.14%) and Escherichia coli (34.14%). Antimicrobial susceptibility testing through Kirby-Bauer disk diffusion method indicated complete resistance (100%) to cephalothin in both Salmonella and Escherichia coli isolates. Escherichia coli demonstrated the highest susceptibility to chloramphenicol (95.75%), whereas Salmonella exhibited full susceptibility to sulfamethoxazole-trimethoprim (100%). Multidrug resistance was prevalent, with 100% of Escherichia coli and 83.33% of Salmonella isolates displaying resistance to multiple drugs. The survey study indicated the widespread misuse of antibiotics and inadequate vaccine management. The administration of vaccines and medications by non-veterinarians were 41.38% and 55.17% in the farms, respectively. Furthermore, the survey showed disease as major challenge and the heightened non-therapeutic use of antibiotics in poultry farms. In conclusion, the study underscores the substantial prevalence and resistance exhibited by Escherichia coli and Salmonella in poultry establishments. To tackle these challenges, the study recommends for the enhancement of antibiotic stewardship, the improvement of vaccine management practices, and the execution of further comprehensive investigations
BOVINE TRYPANOSOMOSIS: EPIDEMIOLOGY AND DRUG RESISTANCE STUDY IN SELECTED SITES OF KELLEM WOLLEGA ZONE, OROMIA REGIONAL STATE, ETHIOPIA
(2019-08) Efrem, Degineh; Hagos Ashenafi (Prof), Dr. Workineh Shibeshi; Dr. Nigatu Kebede
African Animal Trypanosomosis remains one of the most important disease constraints to livestock and mixed crop-livestock farming in tropical Africa. Trypanosomosis is responsible for the death of 3 million heads of cattle yearly, with 50 million animals at risk in sub-Saharan Africa. The problem of trypanosomosis is still far from being solved due to the fact that trypanosomes affect multiple hosts, widespread trypanocidal drug resistance and antigenic variation displayed by the trypanosomes. Trypanocidal drugs: Isometamidium chloride (ISM) and Diminazene aceturate (DA) are the most widely used drugs for control of animal trypanosomosis in Ethiopia. In Kellem Wollega, trypanosomosis is one of the main livestock diseases. In the area, a number of brands of trypanocidal drugs from various sources are routinely used by veterinary professionals as well as farmers, which may result in rampant misuse and under-dosage of the medications, actions which might contribute for the emergence of trypanocidal drug resistance. However, study on trypanocidal drug resistance is not yet carried out despite of serious complains of drug failure from professionals and farmers. Therefore, the present study in Gidami and Sayo selected districts of Kellem Wollega Zone of Oromia Regional State; Ethiopia was designed to investigate the problem of bovine trypanosomosis with special emphasis on epidemiology of the disease and assessment of trypanocidal drug resistance. Accordingly, questionnaire survey, cross-sectional studies and field trypanocidal drug resistance trial on naturally infected cattle were used to assess the epidemiological picture of the disease and the utilization of trypanocidal drug practices and evaluate the current status of trypancidal drug resistance trypanosomes. In the questionnaire survey, a total of 100 farmers were interviewed, of which 50 from Gidami and 50 from Sayo districts to assess the knowledge, attitude and practices of farmers towards the control of bovine trypanosomosis. A cross-sectional vector survey was conducted in purposively selected eight villages of Gidami and Sayo districts from November, 2015 to June, 2017 in early dry and early rainy seasons. A total of 160 traps (80 per district) were deployed at approximate intervals of 100 to 200 meters for 48 hours at watering and grazing points of animals in two seasons. For cross-sectional study of bovine trypanosomosis a total of 1790 blood samples were collected from systematically selected cattle and examined by buffy coat blood examination technique during early dry and early rainy seasons in Gidami and Sayo districts. Based on the outcome of the cross-sectional study Kellem and Gry Sonka villages from Gidami district were selected for field trypanocidal drug resistance study. An abbreviated 28-day field prototudycol was used to estimate resistance to 1 mg/kg b.w ISM and 7.0 mg/kg b.w DA trypanosome-positive cattle. For this purpose a total of 100 parasitaemic cattle from Kellem and Giray Sonka villages were selected and treated with Isometamidium chloride and Diminazene aceturate and monitored for trypanosomes and packed cell volume (PCV) levels on days 14 and 28 post treatment. Based on the questionnaire survey, 100% of the respondents from Gidami and Sayo district indicated trypanosomiasis as the major important disease of livestock causing considerable direct and indirect economic losses. Isometamidium chloride and Diminazene aceturate are the commonly used drugs to treat bovine trypanosomosis in both study districts. Sixty percent of respondents from Gidami and only 9% from Sayo districts disclosed that they treat their animals nine to fifteen times per year per animal. Trypanocidal treatment failures were reported by 98% and 76% of the respondents from Gidami and Sayo district, respectively. Among 3289 flies trapped during the study period 1739 (52.88%) were Stomoxys, 1158 (35.21%) Glossina, 252 (7.66%) Tabanus and 140 (4.25%) were Haematopota. The overall apparent fly density was 10.28 flies per trap per days. The apparent density of Glossina, Stomoxys, Tabanus and Haematopota were 3.62, 5.43, 0.79 and 0.44 flies per trap per day, respectively. Four Glossina species: G. tachinoides, G.m.sub-morsitans, G. palidipes and G. fuscipes were recovered in Sayo district. However, only G.m.submorsitans and G. palidipes were caught in Gidami district. Out of the total 1158 tsetse flies caught, 51.81% were G. pallidipes; the remaining 25.65%, 16.58% and 5.96% were G. m. submorsistans, G.fuscipes and G. tachnoides, respectively. The overall prevalence of bovine trypanosomosis was 14.08% (95% CI: 12 -16%) and 11.16 % (95% CI: 9-13%) in Gidami and Sayo districts, respectively. However, there was no statistically significant difference (P > 0.05) between these two districts in the prevalence of bovine trypanosomosis. In the present study, the trypanosome prevalence was higher in low altitude (18.09, 13.80%) compared to mid altitude areas (9.13, 8.5%) in Gidami and Sayo districts respectively. The observed difference was found to be statistically significant (P<0.05). Trypanosoma congolense being the predominant species (57.30%) followed by T. vivax (29.10%), T.b.bruci (9.70%) and mixed infection of T. vivax and T. congolense (3.90%) were the prevailing trypanosome species in the area. The overall bovine trypanosomosis prevalence was siginificantly varied between poor (25.37%) compared to both medium (10.02%) and good (2.66%) body conditioned animals and between adult (14.16%) and young (9.38%) age categories. There was no statistically significant difference (P>0.05) in the prevalence of bovine trypanosomosis between sexes of the examined animals. There was a statistically significant difference (P<0.05) in the mean packed cell volume (PCV) between parasitaemic (21.53%) and aparasitaemic cattle (26.11%) regardless of district and season of sampling. The results of field trypanocidal drug resistance study confirmed the presence of drug resistance to the maximum recommended doses of ISM and DA in Giray Sonka and Kellem villages of Gidami district. From 50 trypanosome positive cattle treated with ISM 2% solution of 1 mg/kg bw, 68% had persistent infections at day 28 post treatment. Similarly, of the 50 trypanosome positive cattle treated with DA 7% solution of 7 mg/kg bw, 36% had persistent trypanosomes at day 14 post treatment. In conclusion, bovine trypanosomosis is a major disease constraint of livestock health and agricultural activity in Gidami and Sayo districts of Kellem Wollega Zone of Oromia Regional State, Ethiopia. Trypanocidal drug resistance is a threat in Kellem Wollega and thus sustainable and integrated tsetse and trypanosomosis control practices should be implemented to ensure productivity of cattle and foster agricultural development. Furthermore, extensive data on trypanocidal drug sensitivity tests using advanced molecular techniques is essential.
COMPARATIVE PATHOLOGICAL STUDY ON LUNG, HEART, KIDNEY AND LIVER OF CATTLE AND DROMEDARY CAMEL SLAUGHTERED AT AKAKI ABATTOIR AND ASSESSMENT OF ASSOCIATED FINANCIAL LOSSES
(2019-06) Emebet, Etisa; Dr. Bulto Giro, Yacob Hailu (Prof)
Lung, heart, kidney and liver are vital organ of the body and susceptible to various disease conditions and parasites that affect the total health status of cattle and camel. There is an increase in demand of carcass and organ consumption but the production capacity become decreasing due to the presence of endemic disease and varieties of pathological conditions. This study was carried out to investigate the pathological changes present in lungs, hearts, kidneys and livers of cattle and dromedarius camels slaughtered at Akaki abattoir. Such studies are very important in epidemiological surveys of animal diseases. Cross-sectional study design with purposive sampling method was used to study pathological findings on lung, heart, kidney and liver of cattle and camels slaughtered at Akaki abattoir. 3520 cattle and 560 camels were involved in the study. The organs from these animals were grossly inspected and the representative tissue samples in 10% neutral buffered formalin were collected for histopathological lesions characterization. Pulmonary hydatidosis was the highest findings in the lung of cattle 39% while emphysema was the highest lesion in camel 30.4%. Grossly the hydatidosis was characterized by having variable size yellowish to grey colored cysts embedded at different depths of lung and microscopically by the presence cystic wall and infiltration of inflammatory cells. The emphysema was characterized grossly by enlargement of the lung due to gas accumulation and microscopically by distention of the alveoli and interlobular septa. The least pathological changes in the lung of cattle were granulomatous pneumonia and CBPP both occurred at same rate 0.12%. Granulomatous pneumonia was characterized grossly by dark red area of streak, dilation of interlobular septa with mucoid like exudates and yellowish to gray caseous and calcified materials in the mediastinal lymphnode. Microscopically, there were granulomatous like lesions around the bronchioles and infiltrated with inflammatory cells and mediastinal lymphnode were necrotized and mineralized. In case of CBPP grossly there was fibrinous pleuritis and marbling appearance and microscopically, interlobular septa were markedly expanded with abundant edema and inflammatory cells. Serous cyst and calcification were the highest finding in heart of cattle and occurred at same rate 33.3% while pericarditis with cysticercosis was the only finding in camel’s heart. The cysticercosis was characterized grossly by hard small size cyst like structure on myocardium of the heart and microscopically by the presence of cyst in the myocardium, with egg in the reproductive tract of female nematode. In cattle kidneys, cysts were the highest pathological condition to be occurred 34% and hypertrophy were the least in occurrence 9.6%. Grossly, there were several small cysts on the cortex of the kidney and in other case single cyst on the medulla of the kidney. Microscopically the cyst was lined by cuboidal type of cells and other lined by single cell layer of epithelium However, abscess and pyelonephritis were highest in camel and occurred at same rate 50%. In camel pyelonephritis was characterized grossly by enlarged kidney due to accumulation of fluid and internal swelling and microscopically by distended tubules contained hyaline cast and heavily infiltrated interstitium. In cattle livers, fasciolosis were the highest pathological findings 52.1% and grossly it was characterized by deposition of rusted colored materials and immature and mature fasciola in the bile duct and microscopically by fibrosis and haemorrhagic portal tracks, metastasis bile duct in to mucus producing like cells and infiltration of inflammatory cells. In camel cystic liver with fatty change was the highest 60% and grossly it was characterized by variable size cysts and slightly elevated nodular like structure on the parietal surface of liver and microscopically by presence of several cystic area lined by single layer of epithelium accompanied by fatty change and Von Meyenburg complex. The monitory losses as the result of organ condemnation were 877,587.08 ETB in cattle and 169,309.03 ETB in camel. In conclusion, the pathological changes observed in one species were not seen in other species and in other cases same pathological changes were seen in both species and . ETB lost due to the organs condemnation from both species as the result of these pathological changes. We recommend further study to be conducted on the root ethological causes of the pathological changes observed in this study.
Control of Tsetse and Trypanosomosis in the Southern Rift Valley (Step Area): Evaluation of Deltamethrin Applications
(2004-06) JEMERE, BEKELE; Prof. Getachew Abebe
A trial aimed to evaluate the efficacy of Deltamethrin (0.4% impregnated odour-baited targets and 1% pour-on formulation applied to animals) in reducing the incidence of bovine trypanosomosis and comparing the corresponding cost-effectiveness of both strategies was conducted in two selected 10X10km Universal Transverse Mercator Grids of the Southern Tsetse Eradication Project (STEP) area in the Southern Rift Valley of Ethiopia. The Grids selected were H3 & G5 designated as study Sites I & II respectively. The trial was underway from late September, 2003 to early April, 2004. The accomplishment of the trial included baseline survey (Questionnaire, Parasitology, and entomology), intervention with insecticide (Deltamethrin 0.4%) impregnated odour-baited targets at Site I(Grid H3) and Deltamethrin 1% ‘pour-on’ application to cattle at Site II (Grid G5) and monthly monitoring of the incidence of disease and apparent density of tsetse fly. Following the deployment of 460 targets (0.4% Deltamethrin impregnated and odour-baited) at a density of 4 targets /km2 at the trial Site I, the relative abundance of tsetse fly (G. pallidipes) population declined from a pre-intervention catch of 1.35 flies/trap/day to 0.05 flies/trap/day during the final trapping time in April, 2004 with about 88.88% overall reduction achieved. The associated disease (trypanosomosis) status was monitored by monthly blood sampling from the sentinel animals established prior to the intervention and the incidence in cattle dropped from 10.75% (first monitoring) to 1.8% (last monitoring) with about 83.25%. The prevalence of the disease had also dropped to 9% (P< 0.01) as compared to the pre-intervention result of 23% and as a result, an overall reduction of 60% was achieved. The corresponding overall mean PCV (packed cell volume) record had shown an improvement from 21.8% of the pre-intervention to 25.5 % (P<0.01) after intervention. Similar assessment at Site II with Deltamethrin 1% pour-on formulation started by applying to about 409 animals at a rate of 1ml/10 kg body weight and subsequently repeated on monthly basis throughout the trial period resulted in a sharp drop of the relative abundance of tsetse fly population to nil from 0.91 flies/trap/day of the pre-intervention catch with a 94.88% (P<0.01) overall reduction achieved. The incidence of the disease also declined from 10% to 0.95% (about 90.5%). The reduction from 21% to 4.75% in the prevalence of the disease was observed to be significant (P<0.01) with a 77.4% overall drop. The associated overall mean PCV value (24.1% increased to 27.2%) had shown a gradual increase (P<0.01) until the third monitoring and maintained a stable state thereafter. The use of Deltamethrin 1% pour-on proved better efficacy based on the results obtained and conclusions made. In addition to this, cost effectiveness evaluation of the intervention component was conducted. This indicated that the routine intervention cost for Pour-on formulation offered Incremental Cost-Effectiveness Ratio (ICER) ranging from 34762.54- 102927.94 USD per unit effectiveness and the use of impregnated odour-baited targets ranging from 43184.93- 942652.00 USD per unit effectiveness for tsetse control and the associated disease (trypanosomosis) reduction. The ranges imply that reasonable variation is lacking between the cost-effectiveness of the two strategies. Though this uncertainty interval ruled out the difference between using targets and pour-on, it seemed that pour-on having lower ICER on average cost and average effectiveness assessments. The integrated application of both strategies was definitely relevant and thus recommended.
A CROSS SECTIONAL STUDY OF DOURINE IN SELECTED HORSE BREEDING DISTRICTS OF BALE HIGHLANDS OF OROMIA REGIONAL STATE OF ETHIOPIA
(2008-06) DEGEFA, GUTA; Dr. Hagos Ashenafi, Dr. Yacob Hailu,
A cross sectional study comprising serological and questionnaire survey was conducted with the objective of determining the prevalence, extent and distribution of Dourine in selected horse breeding districts of Bale highlands of Oromia Regional State of Ethiopia from September 2007 to May 2008. Parasitological survey in an attempt to determine the parasitological prevalence and to isolate T. equiperdum in 71 purposively selected clinical Dourine cases revealed no trypanosomes by Giemsa staining or by Haematocrit Centrifugation Technique (HCT). A total of 880 sera were tested for the detection of antibodies against the causative agent of Dourine in four selected horse breeding districts of the Bale highlands of Ethiopia. Accordingly, the sero prevalence of Dourine was found to be 140 (15.90 %) and 173 (19.66 %) for CATT / T. evansi and LATEX / T. evansi tests, respectively. Body condition and parity number were found to have significant difference (p < 0.05) on the sero prevalence of the disease based on the CATT/ T. evansi test only. However, age, sex, history of previous abortion and castration status no significant difference (p > 0.05) on the sero prevalence of the disease using CATT/ T. evansi test. On the other hand neither of the explanatory variables had significant difference (p > 0.05) using LATEX/ T. evansi test. Logistic regression analysis revealed that horses without parity number (0) had an OR of 1.80 (1.02, 3.19) positivity compared to horses with parity number (1 and above); and horses with poor body condition (thin and very thin) had an OR of 1.44 (1.00, 2.08); positivity compared to horses with moderate body condition (less thin, less moderate and moderate) scores, on the basis of CATT/ T. evansi test. The questionnaire survey indicated that dourine is the major health problem of horses in the selected horse breeding districts of Bale highlands of Ethiopia and locally known as “Derisa” in Oromifa language and “Tigen” in Amharic language that causes high mortality and economic loss in selected horse breeding districts of Bale highlands of Ethiopia. It is a common clinical case throughout the year, however the disease has a seasonal character, which most commonly occurs whenever animals are in a good body condition and following the breeding season from April to late September and during dry season of the year (January to March), which probably associated with the relapse of previously infected and recovered cases due to the stressful condition of feed shortage. Uncontrolled breeding, unrestricted animal movement and absence of officially approved effective trypanocidal drugs against dourine cases are the main factors that play an important role in the distribution and transmission of the disease. X Even though there was no direct parasitological detection of T. equiperdum, the result of serological survey conducted by using CATT / T. evansi and LATEX / T. evansi tests together with the questionnaire survey, provides strong evidence that Dourine is highly prevalent, most important problem in selected horse breeding districts of Bale highlands of Ethiopia, where the problem of dourine is still unsolved. Further more, in view of large number of horses in Ethiopia and the unrestricted movement of animals throughout the country it is likely that dourine may be more widespread in Ethiopia than is currently realized.
A CROSS SECTIONAL STUDY OF DOURINE IN SELECTED HORSE BREEDING DISTRICTS OF BALE HIGHLANDS OF OROMIA REGIONAL STATE OF ETHIOPIA
(2008-06) DEGEFA, GUTA; Dr. Hagos Ashenafi, Dr. Yacob Hailu,
A cross sectional study comprising serological and questionnaire survey was conducted with the objective of determining the prevalence, extent and distribution of Dourine in selected horse breeding districts of Bale highlands of Oromia Regional State of Ethiopia from September 2007 to May 2008. Parasitological survey in an attempt to determine the parasitological prevalence and to isolate T. equiperdum in 71 purposively selected clinical Dourine cases revealed no trypanosomes by Giemsa staining or by Haematocrit Centrifugation Technique (HCT). A total of 880 sera were tested for the detection of antibodies against the causative agent of Dourine in four selected horse breeding districts of the Bale highlands of Ethiopia. Accordingly, the sero prevalence of Dourine was found to be 140 (15.90 %) and 173 (19.66 %) for CATT / T. evansi and LATEX / T. evansi tests, respectively. Body condition and parity number were found to have significant difference (p < 0.05) on the sero prevalence of the disease based on the CATT/ T. evansi test only. However, age, sex, history of previous abortion and castration status no significant difference (p > 0.05) on the sero prevalence of the disease using CATT/ T. evansi test. On the other hand neither of the explanatory variables had significant difference (p > 0.05) using LATEX/ T. evansi test. Logistic regression analysis revealed that horses without parity number (0) had an OR of 1.80 (1.02, 3.19) positivity compared to horses with parity number (1 and above); and horses with poor body condition (thin and very thin) had an OR of 1.44 (1.00, 2.08); positivity compared to horses with moderate body condition (less thin, less moderate and moderate) scores, on the basis of CATT/ T. evansi test. The questionnaire survey indicated that dourine is the major health problem of horses in the selected horse breeding districts of Bale highlands of Ethiopia and locally known as “Derisa” in Oromifa language and “Tigen” in Amharic language that causes high mortality and economic loss in selected horse breeding districts of Bale highlands of Ethiopia. It is a common clinical case throughout the year, however the disease has a seasonal character, which most commonly occurs whenever animals are in a good body condition and following the breeding season from April to late September and during dry season of the year (January to March), which probably associated with the relapse of previously infected and recovered cases due to the stressful condition of feed shortage. Uncontrolled breeding, unrestricted animal movement and absence of officially approved effective trypanocidal drugs against dourine cases are the main factors that play an important role in the distribution and transmission of the disease. X Even though there was no direct parasitological detection of T. equiperdum, the result of serological survey conducted by using CATT / T. evansi and LATEX / T. evansi tests together with the questionnaire survey, provides strong evidence that Dourine is highly prevalent, most important problem in selected horse breeding districts of Bale highlands of Ethiopia, where the problem of dourine is still unsolved. Further more, in view of large number of horses in Ethiopia and the unrestricted movement of animals throughout the country it is likely that dourine may be more widespread in Ethiopia than is currently realized.
Cryptosporidium in Dairy Cattle, Sheep, Humans, and Manure in and around Adama and Asella Towns, Oromia Regional State, Ethiopia
(Addis Abeba University, 2022) Kassahun Berhanu; Dr.Dinka Ayana
In Ethiopia, several studies have reported the occurrence of Cryptosporidium infection in young calves, lambs, and HIV positive patients. However, studies on cattle and sheep of all age categories, and humans (farm workers and animal owners) were limited. A cross-sectional study design was thus conducted from October 2021 to April 2022 to study the occurrence of Cryptosporidium in dairy cattle, sheep, humans, and manure in and around Adama and Asella towns, Oromia, Ethiopia. Dairy cattle and sheep were stratified according to their age and randomly sampled. Stool samples from volunteered farm workers and household members were collected purposefully. A semi-structured questionnaire was also used to collect information about manure handling practices. All samples (dairy cattle = 234, sheep = 200, humans = 56, manure = 58) were processed with sugar floatation technique and the modified Ziehl-Neelsen staining method. A univariate regression analysis was used to test the association of individual factors with the occurrence of Cryptosporidium. Associated factors were subjected to multivariate regression analysis to identify potential risk factors. The overall prevalence of Cryptosporidium in dairy cattle, sheep, humans, and manure was 20.5%, 14%, 16%, and 13.20%, respectively. The occurrence of Cryptosporidium infection in dairy cattle at the ages of 1–12 months and 13–36 months was 3.48 and 3.07 times higher, respectively, in comparison to the age above 36 months. Similarly, the occurrence was 2.69 times higher in sheep aged 1–6 months than in those aged older than 6 months. And also, a higher average level of oocyst count (above 10 oocysts) per-field was examined in dairy cattle (3/48) aged 1– 12 months, followed by sheep (1/28) aged 1–6 months. Furthermore, the likelihood of infection was 13 times greater in farm workers compared with the rural farmer members. In addition, the occurrence of oocysts was 22.8 times higher in manures from dairy cattle than manure from sheep. From data on manure handling practices, only 16.8% of them had manure storage holes, 98.1% used manure for crop production, and all of them used manure without treatment. The current study revealed the occurrence of Cryptosporidium infection in all age groups of dairy cattle and sheep, farm workers, animal owners, and manures. Therefore, more studies on adult animals and manure is required to investigate their contribution to environmental contamination as well as their role as a source of infection in young calves and lambs. In addition, molecular characterization is also required to identify the zoonotic species of Cryptosporidium
EPIDEMIOLOGICAL STUDY OF BOVINE TRYPANOSOMOSIS IN GORO AND AMEYA-KOTA DISTRICTS OF SOUTHWEST SHOA ZONE, OROMIA NATIONAL REGIONAL STATE, ETHIOPIA
(2008-06) TILAHUN, AYELE; Dr. Yilkal Asfaw, Dr. Yakob Hailu
An epidemiological study of bovine trypanosomosis was carried out from September 2007 to March 2008 in Goro and Ameya-Kota districts of Southwest Shoa Zone, Oromia National Regional State, Ethiopia. The objectives of the study were to determine the prevalence of the disease and associated risk factors, evaluate the apparent densities and distributions of tsetse and other biting flies and to know the community awareness concerning the disease and control method in the study area. The study methodology comprises seasonal cross-sectional studies in late rainy and dry seasons in 2007/2008 by using parasitological, entomological and questionnaire surveys. A total of 1200 animals, 600 in the late rainy and 600 in the dry seasons, were examined and the prevalence of trypanosomosis was found to be 33.5% and 17.83% in the late rainy and dry seasons, respectively, with a statistically significant difference (p<0.05) between seasons. The mean PCV values of the parasitaemic and aparasitaemic animals during the late rainy season were 20.19% and 26.75% while during the dry season 18.75% and 23.97% respectively. The entomological survey showed that G.pallidipes, G.m.submorsitans and G.f.fuscipes were prevalent tsetse species along with other biting flies (tabanids and muscids) in the study area. The apparent densities of tsetse flies were statistically significantly different (p<0.05) between the late rainy season (1.05 fly/trap/day, 0.26 fly/trap/day, 1.56 fly/trap/day) and the dry season (0.56 fly/trap/day, 0.11 fly/trap/day 0.59 fly/trap/day) for G. pallidipes, G. morsitans submorsitans, G.fuscipes fuscipes, respectively. The overall apparent densities of tsetse flies were found to be 2.87 fly/trap/day (95% CI= 1.04-5.77%) and 1.26 flay/tap/day (95% CI= 1.17-2.07%) in late rainy and dry seasons, respectively. G.f.fuscipes and G.pallidipes appears to be dominant during the course of the study period, whereas lower catch was observed for G.m.submorsitans than G.pallidipes and G.f.fuscipes. The proportion of female tsetse flies caught was higher in both seasons. G.pallidipes was considered to be active transmitter of the disease compared to G.m.submorsitans and G.f.fuscipes. Also the apparent densities of other biting flies were significantly higher (p<0.05) in the late rainy season (1.49 fly/trap/day, 18.66 fly/trap/day) than the dry season (0.77 fly/trap/day, 15.04 fly/trap/day) for tabanids and muscids, respectively. The overall apparent densities of biting flies were found to be 20.15 fly/trap/day (95% CI= 14.23-26.03%), and 15.81 fly/trap/day (95% CI= 10.86-20.75%) in late rainy and dry seasons, respectively. The questionnaire survey revealed that trypanosomosis is the most economically X important disease affecting cattle in Goro and Ameya-Kota sites of the study area. All of the interviewed farmers indicated that bovine trypanosomosis ranks first as the major animal health constraint impairing agricultural development. Also they suggested that the occurrence of trypanosomosis was higher in the late rainy season than the dry season. Most of the curative and preventive trypanocidal drugs in the study area were misused by drug smugglers and non professionals. Hence, trypanosomosis is the most important challenge for agricultural activity and animal production in Goro and Ameya-Kota districts, and the situation is getting worse as the control and prevention of trypanosomosis is facing a lack of vector control activities in the area.
EPIDEMIOLOGICAL STUDY ON HEMOPROTOZOAN PARASITES OF ZEBU CATTLE IN AMBO AND TOKE KUTAYE DISTRICTS OF WEST SHEWA ZONE, OROMIA, ETHIOPIA
(2017-06) GUDINA, MEKONNEN; Dr. Dinka Ayana , Dr. Hagos Ashenafi
A cross sectional study was conducted from October, 2016 to May, 2017 to determine the prevalence of hemoprotozoan parasites, to detect the species of hemoprotozoa parasites, to identify the vectors of hemoprotozoal parasites and risk factors associated with the occurrence of hemoprotozoal parasites in cattle in Ambo and Toke Kutaye districts of West Shewa Zone. A total of 384 blood samples were collected from randomly selected cattle to assess the presence of hemoprotozoan parasites by using buffy coat and thin smear technique and stained using Giemsa stain and identified by using oil immersion objective lens light microscope. The three hemoprotozoan parasites identified in the study area were Babesia bigemina, B. bovis and Trypanosoma vivax. The overall prevalence of hemoprotozoan parasite in the study area was 9.4% (7.6% Babesia bovis, 1% B. bigemina, 0.8% T. vivax). Statistically significant difference was observed between groups of sex, age, body score condition and tick infestation of cattle in presence of hemoprotozoal parasite. Out of the total positive cattle with hemoprotozoal parasite 72% (26/36) of them were anemic (their packed cell volume values less than 25%) and the rest 28% (7/36) of them were not anemic (their packed cell volume value greater or equal to 25%) which is statistically significant. The major tick species identified in the study area include Rhipicephalus spp Amblyomma spp Hylomma spp and Rhipicephalus (Boophilus) spp Tabanus, Stomoxys and Chrysops were the biting fly species identified in the study area.
Epidemiology of Cattle ond Sheep Fasciolosis in Selected Abattoirs of Ethiopia and Estimation of the Associataed Economic Losses Due to Lvier Condemnation and Coprological Study in and around Debreberhan and Evaluation of the Immune Response of Sheep Against Primary Experiential Infection with Fasciola Hepatica Metacercariae
(2021-06) Abebayehu, Tadesse; Prof. Hagos Ashenafi), Dr. Dinka Ayana)
Fasciolosis is an economically important disease of ruminants which affects mainly sheep and cattle worldwide and causes important economic losses in the animal husbandry. These losses are attributable to mortality, morbidity and condemnation of livers at slaughter. In Ethiopian highlands, sheep and cattle production has remained as an important sector of the country’s agricultural economy. However, their potential has been exploited far less than expected due to several constraints including shortage of forage, poor livestock management and diseases. In Ethiopia, fasciolosis is widespread encompassing the major productive highland plateaus except very limited areas in arid escarpments. The study of liver flukes in live animals depends on the detection of faecal eggs and the use of faecal egg counts. However, these detect only patent infections and their interpretation is constrained by the paucity of information about how they relate to parasite burdens and pathology. Moreover, abattoir-based studies have been used as a component of the study of the liver fluke and to describe various aspects of liver fluke infection. Controlling fasciolosis by vaccination rather than chemotherapy would be a cheaper, more efficient and reliable long term solution for the prevention of infection and eradication of its transmission. Regardless of several attempts, vaccines against Fasciola hepatica were not yet produced to the point of commercialization. A variety of irradiation-attenuated parasite species have been used experimentally to induce protection in various host species. These studies have demonstrated that development of vaccine is potentially feasible. The present study entitled "Epidemiology of cattle and sheep fasciolosis in selected abattoirs of Ethiopia and estimation of the associated economic losses due to liver condemnation and coprological study in and around Debreberhan and evaluation of the immune response of sheep against primary experimental infection with Fasciola hepatica metacercariae" was undertaken in five abattoirs (Debreberhan, Addis Ababa, Bahrdar, HELMIX, ELFORA) while the experimental study was conducted at Aklilu Lemma Institute of Pathobiology. The objectives of the study were to assess the abattoir and coprological prevalence fasciolosis in sheep and cattle and assessment of the associated economic losses in three municipal and two export abattoirs as well as the vaccine trail on immune response of sheep to primary infection with attenuating irradiating dose of Fasciola hepatica metacercariae. The present findings on ruminants at five abattoirs had shown higher prevalence of fasciolosis (46.6% ± 0.059). However, this was much lower that observed in Debreberhan abattoir for sheep (84%) and cattle (77.8%). Overall fasciola infections were only diagnosed in 605 (53.8%) animals coprologically. The highest prevalence was for sheep (60.1%) and followed by cattle (49.2%). The overall herd level infection prevalence, as estimated from the egg-shedding index, was 50.9±29.3. In Debreberhan abattoir, F. hepatica was a dominant (87.9%) species identified followed by F. gigantica (6.3 %). However, this prevalence was much higher than that observed in five of the abattoirs altogether for F. hepatica (70.9%) and F. igantica (21.5%). The overall prevalence of fasciolosis observed in ruminants slaughtered in export abattoirs was 34.6% (877/2530) whereas it was significantly higher in ruminants slaughtered at municipal abattoirs 65.2% (1653/2530) as the whole. The mean annual financial loss recorded altogether in export and municipal abattoirs was 7, 049, 638 ETB / 335, 697.1 USD. The immune response to the infection was proved by the production of specific IgG1 antibodies to irradiated F. hepatica. The parasite viability was severely affected by doses of γ- irradiation of 120 Gy or 240 Gy. In the aforementioned doses relatively low numbers of mature flukes of about 60 (17.1%) and 38 (10.8%) were recovered than the control group, respectively. The sensitized lambs also showed less hepatic damage compared with the controls as indicated by lower liver lesions and lower levels of the serum enzyme glutamate dehydrogenase and γ- glutamyl transferase. The IgG1 antibody titers measured by ELISA vary with the dose of γ- irradiation. Sheep vaccinated with 240 Gy produced the highest antibody titre compared to the non sensitized positive controls. In conclusion, the present study plainly disclosed the high prevalence of fasciolosis both at herd and individual animal level and at abattoir survey. The eggs shedding index seemed to be useful approach in current epidemiological survey than the individual animal coprologic examination. The present findings on ruminants at abattoirs had shown higher prevalence of fasciolosis with significant annual financial loss. Vaccination of sheep with γ-irradiated metacercarae invariably yielded the specific immune response to different treatment groups. Irradiation of F. hepatica had resulted in reduced hepatic damage during migration of juveniles and a strong local immune response, represented by infiltration lymphocytes, eosinophils and macrophages and antifasciola IgG1 titers
EXPERIMENTAL STUDIES ON CLINICO- HEMATOLOGY OF TRYPANOSOMA EQUIPERDUM INFECTED HORSES AND VENEREAL TRANSMISSION IN MICE
(2017-06) Merga, Daba; Dr. Hagos Ashenafi, Merga Bekana (Prof); Dr. Ahmed Yasin
Dourine is an endemic venereal transmitted trypanosomosis causing a major health problem threatening the life and productivity of the equine population in Ethiopia. The present experimental study was conducted from November 2016 to June 2017 in Bishoftu, central Oromia, Ethiopia. The objective of the study was to evaluating clinico-hematological profile of horses experimentally infected with Trypanosoma equiperdum, assess the effect of cymelarsan treatment on hematological values of horses infected with T. equiperdum and determine the possibility of venereal transmission of T. equiperdum in mice. The study design was conducted on (n=4) mares and (n=4) stallions. Mares were challenged by insemination of semen originated from non-infected stallion after mixed with T. equiperdum at a dose of 100,000 parasite/ml by artificial insemination whereas stallion group were infected with 2ml of blood that drawn from infected mare at dose of 1x106 parasites /ml via intravenous route. Data on parasitaemia, rectal temperature, serology (CATT/T. evansi test) and hematological were determined before and after infection. Furthermore infected horses were divided into two groups designated as treated and non-treated groups. At weeks 6 of post infection treatment group was injected with cymelarsan® at dose of 0.25mg/kg body weight. Changes in clinical sign, parasitemia and hematological values were monitored. Thirty (n=30) female mice and male (n=12) were involved in experiment to check coital transmission. One infected mouse was co-housed with two healthy female mice at low level of parasitemia (1x101-1x103) in six replications and other one infected male mouse co-housed with two healthy female mice at high level of parasitemia (1x104-1x106) in six replications. Other two infected female co-housed with four healthy female as control. Thereafter the appearance of Parasitemia was monitored daily from female mice. The study revealed that, Dodola strain caused a severe change in blood parameter and a clinical sign in both stallion and mare, infection was predominantly characterized by involvement of genital, nervous and corneal signs. There was significant decrease in mean PCV, Hg, RBC, eosinophil, basophil and monocyte count while mean total WBC and neutrophil count had no significant difference (p>0.05) in animals post-infection when compared to pre-infection values. Lymphocyte and MCHC were significantly (p<0.05) higher at post infection as compared to pre-infection. Cymelarsan treatment at dose of 0.25 mg/kg body weight failed to clear the parasite and improve in clinico-hematological values, rather being relapsed after 21days. Treated group had no significant improvement in RBC, Hgb, and differential leukocyte count whereas PCV and WBC which were significantly (p < 0.05) improved as compared to non-treated group. In healthy female mice co-housed with infected male mice using wet smear no trypanosomes were detected in all female mice and their offspring in wet smear throughout study period. In conclusion the current study revealed that dourine resulted in hematological changes that lead to normocytic hypochromic anemia, thus further elucidative investigation recommended on pathogenesis of the disease. In addition, venereal transmission of T. equiperdum in mice was unsuccessful; hence further molecular based test is essential to ascertain this result.
Experimental Trichostrongylus Colubriformis Infection Profile in Sheep and Goats and in Vitro Nematocidal Effect of Arthrobotrys Oligospora against L3 of the Parasite
(2020-06) Tamirat, Kaba; Dr. Getachew Terefe, Dr. Gezahegn Mamo
Trichostrongylus colubriformis is one of the major gastro intestinal nematodes (GINs), which cause severe morbidity and mortality in small ruminants worldwide. This comparative study on the infection profile of sheep and goats with an intestinal worm Trichostrongylus colubriformis was aimed to assess the performance of the parasite and the responses of the hosts. It also evaluated the effect of a local isolate of nematophagus fungus species, Arthrobotrys oligospora on the L3 of the parasite in vitro. A total of 14 sheep and 14 goats were employed in such a way that half of them were drenched with 10000 L3/animal and the remaining halves were uninfected controls. The infection profile and impacts of infection on the animals were assessed by measuring faecal egg count, packed cell volume and body weight gain for up to 8 weeks. After 8 weeks of infection, experimental animals were killed in humane manner, worms were recovered from the intestines, counted, and worm burdens were determined. In addition, nematophagous fungus (Arthrobotrys oligospora) was used for in vitro trial against L3 after incubating the fungus and the worms in potato dextrose agar supplemented with 0.05% chloramphenicol. Accordingly, faecal egg count at 18, 45, 52 and 56 days post infection was significantly higher in goats than in sheep, and so is worm burden at the end of the study (P<0.05). Packed cell volume was significantly reduced in both sheep and goats (P<0.05). However, it came back to normal earlier in sheep while it remained significantly lower than the value of control in infected goats. Goats experienced significantly lower weight gain compared with sheep. In vitro trial revealed, Arthrobotrys oligospora reduced survival of 84% of infective larvae after 10 days incubation. In conclusion, sheep performed better than goats to the impacts of experimental infection by T. colubriformis based on assessed parameters. Efficacy of the local strain of A. oligospora is a promising step for future biological control options against nematodes. Therefore, husbandry management of small ruminants particularly goats, in which infection results in severe production loss, in the areas where T. colubriformis prevails should use local epidemiological knowledge and focus on minimizing the exposure to infective stage in the field. A wide scale in vitro trail and further in vivo studies about efficacy of Arthrobotrys oligospora against T. colubriformis and other GINs is also recommended.
Hematophagous Flies Species Diversity, Efficiency of Traps and Assocaited Protozoan Pathogens in Cattle in Arba Minch Zuria, Mirab Abaya and Kucha Districts of Gamo Zone
(2020-06) Birhanu, Haile; DR. Bersissa Kumsa
Hematophagous flies like Glossina species, Tabanid, and Stomoxys are economically very important parasitic arthropods affecting domestic animals and humans due to their persistent and painful bites, annoyance, blood-feeding behavior and vectors of pathogens. Despite their great importance of Tabanids and Stomoxys only little information is available about these biting flies in Ethiopia. The little information from Ethiopia on these arthropods was reported by few investigators only at the genus level during their studies on Glossina in some areas. The objectives of the present study were to identify hematophagous fly species affecting domestic animals in the study area, to detect associated blood parasites affecting cattle and to compare catching efficiency of NGU, Biconical and Sticky types of traps in three different districts, viz, Arba Minch, Mirab Abaya and Kucha districts found in Gamo zone. For this purpose, a total of 87 traps were deployed at 29 sites by rotating NGU, Biconical, and sticky panel for sampling the flies, and a total of 409 blood samples were collected from cattle. A total of 2985 flies were collected during the study period were morphologically identified into 2536 (85%) genus Glossina, 234 (7.8%) Stomoxys, and 215 (7.2%) Tabanid. The result of the study demonstrated that the genus Glossina 85% (2536/2536) comprised the majority and the predominant proportion of the collected flies followed by 234 (7.8%) Stomoxys and 215 (7.2%) Tabanid. The results of fly identification revealed the presence of two tsetse species G. pallidipes 79.1% (n= 2005/2536) collected from all the three study districts, however, G. fuscipes 21% (n=531/2536) was collected only from Kucha district. A total of 12 species were twelve species identified were; Ancala. Africana, Atylotus agrestis, Tbanus donaldsoni, T. gratus, T. taeniola variatus, T. taeniatus, T. par, Stomoxys. n. nigra, S. sitiens, S. indica, Glossina pallidipes and G. f. fuscipes. Haematopota and chrysop were identified in to genus level. Apparent densities (AD) of Tabanids, Stomoxys, G. f. fuscipes. Haematopota and chrysop were identified in to genus level. Apparent densities (AD) of Tabanids, Stomoxys, G. f. fuscipes, and G. pallidipes collected from Arba Minch were 1.72, 2.6, 0 and 20.8, respectively. In Mirab Abaya district the apparent densities (AD) of Tabanids, stomoxys, G. f. fuscipes, and G. pallidipes were 0.18, 1.27, 0 and 14.61 whereas in Kucha district the AD of 0.18, 0.3, 8.85 and 0.08 was recorded for Tabanid, Stomoxys, G. f.fuscipes, and G. pallidipes, respectively. The overall catch of G. pallidipes in Arba Minch was significantly higher than the catch in Mirab Abaya (P= 0.0006) and Kucha (P=0.0000) districts. The overall catch of the sticky trap of all fly types was significantly higher than the biconical trap. The Biconical viii trap showed significantly better efficiency (P= < 0.05) than NGU in the catch of Stomoxys and G. f.fuscipes. But the NGU trap showed better catch efficiency (P= < 0.0002) in G.pallidipes and Tabanids than the biconical trap. Of 409 blood samples examined by BCT, 15 were positive for Trypanosomes (n=3 T. vivax, n=12 T.congolensie) and prevalence was 3.4%. The overall mean PCV of cattle positive for trypanosomes was 20.4 which, however, the overall mean PCV of cattle negative for trypanosomes was 28.05.
The Impact of Ghibe-III Hydroelectric Dam on Bovine Trypanosomosis Situation: Tsetse Fly Population Dynamics, Prevalence of Disease and Community Perception in Selected Districts in Op- stream and Down-stream of the Reservoir
(2021-10) Solomon, Mekuria; Prof. Getachew Terefe, Prof. Hagos Ashenafi; Prof. Nigatu Kebede
African Animal trypanosomosis is one of the most economically devastating diseases of livestock in sub-Saharan Africa. The persistence of its tsetse vectors and consequently the severity of the disease in a certain population largely depend on the maintenance of favorable ecological conditions in the area. This study was primarily initiated to assess spatial and temporal changes in tsetse distribution and trypanosome prevalence upstream (Loma District) and downstream (Kindo Didaye District) the Ghibe - III hydroelectric dam area to appreciate if the dam has any impact. Questionnaire surveys with 189 respondents using semi-structured questionnaire and focus group discussions (FGD) with 15 groups each containing 6-20 members were conducted by matrix scoring with local community to assess their perceptions on the disease situation and its tsetse fly vectors. Triangulation was done to evaluate the relationship between farmers’ perception and trypanosomosis prevalence and impact in cattle. Tsetse flies were trapped by deploying 160 NGU traps at an interval of 200m air distance starting from the fringe of water bodies and animals were bled in dry and wet seasons from selected kebeles’ of both districts to assess the situation as we go away from the Ghibe III dam reservoir in the upstream and from the Omo River downstream. The findings from the interviews and FGD revealed that: 1) cattle herd size greater or equal to six have significantly increased after dam construction in Loma district, whereas in Kindo Didaye farmers with such cattle herd size have declined, 2) Bovine trypanosomosis was ranked as number one disease priority in both Loma (upstream) and Kindo Didaye (downstream) Districts, and 3) Strong concordance observed between diseases and their clinical symptoms as well as impacts on animal health and production. Trypanosomosis prevalence and tsetse distribution studies showed: A) no difference between the two study districts in disease prevalence and tsetse apparent density (TAD) before dam construction, B) both TAD and trypanosomosis prevalence were significantly lower upstream the dam (Loma) than downstream (Kindo Didaye) study sites five years after dam construction (P<0.05), C) prevalence of the disease was reduced from 17.9% in 2005 before dam construction to 6.4% in 2019/20 in upstream (Loma) and from 19.2% in 2005 to 11.7% in 2019/20 in downstream, D) the most prevalent trypanosome species were T. congolense and T. vivax while few cases of T. brucei were seen in Kindo Didaye, E) tsetse apparent density was reduced from 10 fly/trap/day (FTD) before dam construction to 1.09 FTD in Loma five years after dam completion and from 13.7 FTD to 5.3 FTD in Kindo Didaye in the same period, but significant reduction was noticed only for Loma (P<0.05), F) Tsetse density was more severe close to the fringe of Omo River in Kindo Didaye whereas it is more important as we go away from the fringe of the dam reservoir in Loma, G) the current study has clearly shown that despite the significant difference in tsetse fly apparent density, tsetse infection rates were almost similar between the two study sites; 12% in Loma and 17.8% in Kindo Didaye. In general, although bovine trypanosomosis is still a major problem in the study areas, Ghibe III dam construction appear to have produced a favorable outcome in areas close to the water reservoir probably by disrupting tsetse ecology and consequently reducing trypanosomosis prevalence. The finding was consistent with community perception. However, the problem is still rampant in areas downstream the dam and in places far away from the dam water reservoir. Based on the above findings, lists of practical recommendations are forwarded.
In Vitro Effecacy of Methanolic Extracts of Vernonia Amygdalina, Croton macrostachyus, Ricinus Communis and Petroleum Ether Extract of Millettia Ferruginea against Bovicola ovis and Rhipicephalus (Boophilus) Decoloratus
(Addis Ababauniversity, 2015-06) Gizaw, Askale; Dr. Giro, Bulto
In vitro loucicidal and accaricidal efficacy evaluation of Vernonia amygdalina, Croton macrostachyus, Ricinus communis and Millettia ferruginea against Bovicola ovis and Rhipicephalus decoloratus of cattle were carried out from January 2014 to April 2015. Crude methanol extracts of Vernonia amygdalina, Croton macrostachyus, Ricinus communis leaf and Petroleum ether extract of Millettia ferruginea seed oil were prepared for in vitro test at different time intervals. The four selected medicinal plants, at concentrations of 200, 100, 50, 25, 12.5 and 6.25mg/ml and a commercially used acaricide (0.1% diazinon), were examined using in vitro adult immersion test. In vitro loucicidal test showed all concentration of Millettia ferruginea oil (μl/ml), ≥25mg /ml concentration of Croton macrostachyus and 200 and 100mg/ml concentration of Ricinus communis had pronounced loucidal activity at 24hr of exposure. 200mg/ml concentration of Vernonia amygdalina and ≤6.25mg/ml concentration of Croton macr ostachyus had moderate loucicidal activity at 24hr of exposure. Moreover, the 200 and 100μl/ml concentration of Millettia ferruginea seed oil and 200mg/ml concentration of Ricinus communis leaf crude extract had high accaricidal activity (90-100%) against Rhipicephalus decoloratus while crude methanolic extracts of Croton macrostachyus and Vernonia amygdalina and even the positive control (diazinon) showed low acaricidal activity (<35%) against the tick species. All plants had significantly (P< 0.05) higher activity against lice than Rhipicephalus decoloratus ticks except Millettia ferruginea at (200 and 100μl/ml) and Ricinus communis (at 200 mg/ml) which showed both accaricidal and loucicidal activity. Therefore the present study concluded that Croton macrostachyus, Ricinus communis and Millettia ferruginea against Bovicola ovis whereas Ricinus communis and Millettia ferruginea against Rhipicephalus decoloratus could be used as potential alternative in the discovery of guide compounds that substitute commercially available acaricides. In addition, the low activity of diazinon on ticks compared to our plant extracts deserves further attention. Key Words: Acaricide, Bovicola ovis, in vitro, loucicide, medicinal plants, Rhipicephalus decoloratus
In vitro Louscidal and Acaricidal Activities of Alkaloid of Calpurnia Aurea and Fractions of Ricinus Communis Extracts Against Linognathus Ovillus and Amblyomma Variegatum
(Addis Ababauniversity, 2016-06) Amante, Morka; Dr. Hailu, Yacob
The present study was designed to evaluate the louscidal and acaricidal activities of alkaloids of Calpurnia aurea and fractions of Ricinus communis leaves extracts. Alkaloid of C. aurea and XIV solvent fractions of R. communis leaves extract at concentrations of 200, 100, 50, 25, 12.5 and 6.25 mg/ml were used for in vitro adult immersion test of ticks and lice, which then were monitored for their mortality rates for 24hrs. The activities of test substances were evaluated against Amblyomma variegatum and Linognathus ovillus, and compared with diazinon 60 EC. After 24hrs post exposure, two higher concentrations of 200 and 100 mg/ml of the alkaloid extract caused 100±0.5% and 100±0.6% lice mortality, and 100±0.33 and 93.3±0.33 tick mortality respectively. The alkaloid extract showed an insignificant difference in its acaricidal and louscidal activity when compared to the Diazinon 60EC at the same concentration (P > 0.05). LC50 and LC90 values (with 95% confidence limits) of the alkaloid of C. aurea for lice and tick were estimated 9.08 mg/ml (6.21-13.47), 17.65 mg/ml (11.71-22.49) and mg/ml 16.69 (11.77, 26.64), 31.69 mg/ml (21.25-50.72), respectively. Based on LC50 and LC90 values, alkaloid extract was found to be more effective in killing of lice than ticks. Dose response data of C. aurea alkaloid extract on L. ovillus and A. variegatum indicated the gradual increase in the mortality pattern with slopes of 3.1188, and 3.2321, and R2 values of 0.9702 and 0.9882 suggesting that 97.02, 98.82% data were correlated with log concentration, respectively. Chloroform and petroleum ether fractions of R. communis extracts showed less louscidal and acaricidal effects than the acetone and methanol fractions extracts based on the calculated LC50 and LC90. At higher concentration of 200 mg/ml, the chloroform and petroleum ether fractions extracts showed weaker activity on both A. variegatum and L. ovillus with significant difference (P < 0.05) when compared to that of diazinon after 24hr post exposure. As compared to the alkaloid extract of C. aurea, fractions of R. communis extracts were less lethal both to lice and tick. Alkaloid of C. aurea and fractions of R. communis extract were shown to induce tick and lice mortality in a time and dose-dependent manner. The results obtained in this study indicate that the alkaloid extract of C. aurea and the polar solvent fractions of R. communis have promising louscidal and acaricidal activities, lending support for further investigation of the plants to isolate the active components. Keywords: Acaricide, Alkaloid, Ambylomma, Calpurnia aurea, Louscidal, Ricinus communis
Investigation of Arthropods and Their Associated Protozoal and Bacterial Pathogens from Apparently Healthy Dogs and Cats in Four Selected Districts of Southern Ethiopia
(Addis Ababa University, 2023) Hana Tadesse; Prof. Bersissa Kumsa; Prof.Rudi Cassini
Dogs and cats are known to host several vector-borne diseases with zoonotic potential; however, little information is available on the epidemiology of these diseases in Ethiopia. The present study aims to investigate the diversity of arthropods and molecular identity of protozoal and bacterial vector-borne diseases in dogs and cats in selected districts of Gamo zone. Cross-sectional study design was used to determine the prevalence of arthropods and vector-borne diseases. Real-time and/or end-point PCR were used to identify vector-borne diseases. A total of 297 dogs and 110 cats were included for ectoparasites and blood samples. Questionnaires were applied for 290 dog and cat owners to obtain information concerning owner’s knowledge about arthropods and vector-borne diseases. The overall prevalence of ticks, fleas and lice in dogs was 36.7%, 69.7% and 4.7%, respectively. Ectoparasite prevalence on dogs was as follows: fleas (Ctenocephalides felis (C. felis) (69.4%), Echidnophaga gallinacea (E. gallinacea) (1.3%), Ctenocephalides canis (C. canis) (1.0%), and Pulex irritans (P. irritans) (0.3%)), ticks (Amblyomma variegatum (A. variegatum) (22.9%), Rhipicephalus sanguineus (R. sanguineus) (14.1%), Haemaphysalis leachi (H. leachi) (8.8%), Rhipicephalus praetextatus (R. praetextatus) (4.0%), and Rhipicephalus pulchellus (Rh. pulchellus) (3.4%)), lice (Heterodoxus spiniger (H. spiniger) (4.0%) and Trichodectes canis (T. canis) (0.7%)) were identified. Blood samples were collected from a total of 273 dogs and then analyzed by real-time and/or end-point PCR for VBDs. The results of the study showed that Hepatozoon canis (H. canis) was the most prevalent pathogen (53.8%), followed by Anaplasma phagocytophilum (A. phagocythophilum) (7.0%), Babesia canis rossi (B. canis rossi) (3.3%), Ehrlichia canis (E. canis) (2.6%) and Anaplasma platys (A. platys) (2.2%). Furthermore, five samples tested positive for Borrelia spp., identified as B. afzelii (n = 3) and B. burgdorferi (n = 2), and two samples for Rickettsia spp., identified as R. conorii (n = 1) and R. monacensis (n = 1). On cats the prevalence of ticks was 2.7% and fleas was 21.8%. Fleas (C. felis (15.5%), and E. gallinacea (7.3%)) tick (H. leachi (2.7%)) was identified from cats. In cats, among Hepatozoon spp., H. felis (n=24; 21.8%) is the more widespread pathogen followed by H. ingwe (n=7; 6.4%), H. lluiperdije (n=7; 6.4%) and H. canis (n=1; 0.9%). Babesia leo (n=1; 0.9%) was identified from one cat. Eight cats were positive for bacterial pathogens, specifically Bartonella spp., (n=2; 1.8%) and Rickettsia spp., (n=6; 5.5%). All cats were negative for Cytauxzoon spp., Anaplasma spp., Ehrlichia spp., and Borrelia spp. Abundance of C. felis, in dogs was significantly higher (p<0.001), while E. gallinacea was significantly more abundant in cats (p=0.002). Ectoparasite occurrence on dogs varied with different factors. A high prevalence of tick infestation was recorded in urban areas (p=0.020) and in lowlands (p<0.001). Nevertheless, the prevalence of A. variegatum in rural area and midland agroecology was significantly higher (p<0.001). Rhipicephalus Sanguineus prevalence was higher in urban areas (<0.001) and in dogs which lives in indoor environment (p=0.003). H. leachi prevalence was significantly higher in midland (p<0.001) and on adult dogs (p=0.001). Fleas are more prevalent in rural (p=0.029) areas compared to urban areas and females was slightly higher infested by fleas than male (p=0.047) dogs. C. felis was more prevalent in female (p=0.038) dogs than males. Around 88.3% owners in the study area had no knowledge about arthropods and VBDs. Majority of the owners (64.8%) never visited veterinary clinics. The findings of A. phagocythophilum and different species of the genera Borrelia and Rickettsia with zoonotic potential from dogs was unexpected and alarming, and calls for further investigation on the roles of dogs and on the tick species acting as vector in this specific context. Other pathogens (H. canis, B. canis rossi, A. platys, and E. canis) are already known to have an important impact on the dogs’ health but have minor zoonotic potential as they were rarely or never reported in humans. Dogs from rural areas were found to be at higher risk for different pathogens, probably due to the presence of other wild canids in the same environment. Moreover, most of the pathogens reported in the studied cat population were identified for the first time in the country. In conclusion, the findings of the present study contribute to a better knowledge of dog and cat ectoparasites and on the epidemiology of associated vector-borne pathogens, in most cases relevant to human and animal health. Therefore, the data presented in this study are important for building new knowledge and this give rise to awareness creation and strengthening veterinary services for companion animals.
Investigation on Trematodes of Ruminants: Current status, Snail intermediate hosts, and Community knowledge in and around Bishoftu, Ethiopia
(Addis Ababa University, 2024) Abraham Diriba; Dr. Geremew Haile; Prof. Getachew Terefe
The occurrence of trematode infections in ruminants, facilitated by their snail intermediate hosts, poses a major concern across the diverse agro ecological regions of Ethiopia. A cross-sectional study was conducted in and around Bishoftu town from November 2023 to April 2024 to determine the current prevalence of trematode infections and associated risk factors in ruminants, identify snail intermediate hosts of trematodes and determine their infectivity through the emergence of cercariae, and assess the knowledge, attitudes, and practices (KAP) of farmers regarding the prevention and traditional management of trematode infections. A total of 336 fecal samples were collected from cattle, sheep, and goats and subjected to copromicroscopic examination. 400 snails were collected, identified and examined for cercarial shedding. The copromicroscopic examination revealed an overall prevalence of 11.61% trematode infections in the study animals. Logistic regression analysis showed that risk factors such as species, age, body condition score (BCS), and season had significant associations with overall trematode infections. The identified genera were Fasciola (8.93%) and Paramphistomum (4.46%), with coinfection of 1.79%. Sheep had higher infection of Fasciola compared to goats and cattle, which was statistically significant (OR = 7.713, 95% CI: 2.197-27.076, p = 0.001). Cattle had higher Paramphistomum infection than sheep and goat which was statistically significant (OR = 18.403, 95% CI: 2.111-160.375, p = 0.008). Young animals had higher Paramphistomum infection compared to old animals (OR = 14.786, 95% CI: 2.295-95.276, p = 0.005). Poor body condition animals were more affected than those with medium and good body condition for both Fasciola (OR = 12.27, 95% CI: 3.097- 48.118, p = 0.000) and Paramphistomum (OR = 6.277, 95% CI: 1.147-34.363, p = 0.034). The semi-dry season was associated with higher Fasciola infection compared to dry season (OR = 3.265, 95% CI: 1.307-8.155, p = 0.011). The malacology study involved the collection of 400 snails, and revealed Lymnaea natalensis (37%), Physa spp (21.25%), Bulinus truncatus (15.75%), Lymnaea truncatula (10%), Biomphalaria pfeifferi (9.5%), and Bulinus africanus (6.5%). The overall cercarial rate of infection of snails was 7.75%, with the highest rate of infection observed in Lymnaea natalensis (13.51%), and followed by Bulinus truncatus (11.11%). Rate of infections varied significantly by species (χ² = 18.76, p = 0.002), habitat type, with ponds having the highest rate (13.48%) (χ² = 15.6, p = 0.004), and season, with higher rates during the semi-dry season (12%) compared to the dry season (3.5%) (χ² = 10.11, p = 0.001). The quiestionnaire survey revealed that there was significant associations (p <0.05) between education level and KAP of farmers; gender and age with knowledge of farmers about trematode infections. In conclusion, the study provided important insights into the epidemiology of trematode infections in the study area and strategic deworming to reduce pasture contamination with flukes and snail control is needed.
Lesion Characterization, Bacterial Isolation and Viral Detection From Respiratory Tract of Dromedary Camels Slaughtered at Addis Ababa Akaki Municipal Abattoir, Ethiopia
(Addis Ababauniversity, 2015-06) Bayou, Kibruyesfa; Dr. Dawo, Fufa
This study was carried out with the aim of lesions characterization, bacterial isolation and identification and viral detection from lesions of respiratory system of dromedary camels slaughtered at Addis Ababa Akaki Abattoir from December 2014 to April 2015. A total of 207 camels were inspected during the study period. Of the lungs inspected, 53 (25.6%) had one or more gross lesions. Interstitial pneumonia 17 (8.2%), pulmonary emphysema 12 (5.8%), bronchopneumonia 11 (5.3%) and atelectasis 5 (2.4%) were among the most xvii frequently detected pulmonary lesions. The difference of gross lesions frequency and distribution was not statistically significant (P>0.05) between male and female camels. However, gross lesions frequency and distribution significantly varied (P<0.05) among different age groups, lung lobes and between right and left lungs. Histologically interstitial pneumonia was characterized by thickening of intra alveolar septae; congested interstitial capillaries and interstitial infiltrations by lymphocytes and other mononuclear cells and suppurative bronchopneumonia by bronchiolar wall and peribronchiolar infiltration with inflammatory cells particularly neutrophils. Whereas, distended alveoli and collapsed alveoli were seen in tissue sections of pulmonary emphysema and atelectasis, respectively. From 53 lungs with gross lesions bacterial isolation and identification was made. A total of 70 bacterial isolates were detected on sheep blood agar plates from 50 (94.3%) of the processed lung tissues. Rhodococcus equi (20%), Aeromonas hydrophila (12.9%), Coagulase negative staphylococci (11.4%), Actinobacillus spp. (10%), Bacillus spp. (10%), Corynebacterium spp. (8.6%) Escherichia coli (7.1%) and Pasteurella spp. (5.7%) were among the major bacterial isolates. Besides, 25 lung samples with gross lesions were processed for viral propagation in tissue culture; 10/25 (40%) of them exhibited morphologic alterations (CPE) on VERO cell monolayer. The presence of virus in the samples was evidenced by rounding, sloughing and aggregation of infected VERO cells. The result of this study highlights that pulmonary lesions could be detected from camels that apparently looked healthy harbouring a number of pathogenic organisms in the lesions. Hence, further study should be conducted on the camels’ respiratory diseases and lesions. Key words: Bacteria, Camel, Ethiopia, Histopathology, Pulmonary lesion, Virus

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