Veterinary Parasitology

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Study on Bovine Trematodes and their Snail Vectors in Enderta District and Mekele Special Zone, Tigray Regional State, Ethiopia
(Addis Ababa University, 2021) Meaza Nigus; Dr. Dinka Ayana; Dr. Assefa Kebede
Trematodes are one of the economical and public health important vector born parasite helminthes in Ethiopia including Tigray. In the current study cross sectional study was conducted in Enderta district and Mekele special zone from November 2020 to May 2021 to assess the socio-economic significance of bovine trematodes and estimate their prevalence, associated risk factors and identify the snail intermediate hosts harboring the parasites in the areas. To achieve these objectives, a combined of coprological examination, post-mortem examination, snail collection and identification and interview was performed. Out of 480 fecal samples examined 10.42% were found positive for at least one genus of bovine trematodes. The specific prevalence for Fasciola, Paramphistomum and Schistosoma was 4.58%, 2.7% and 3.12%, respectively. Similarly, the prevalence of bovine trematodes in males (14.2%) was higher than that of females (6.44%) and the variation was statistically significant (X2 =7.76, p= 0.012). On the other hand, prevalence in poor body condition (25.7%) was higher than that of medium body condition (7.41%) as well as good body condition (3.9%) and the variation was statistically significant (X2= 28.7, p= 3.73e-09). In the other case, out 480 cattle slaughtered at Abergelle international abattoir 12.5% (n=60) were found to harbor adult trematode worms. The economic loses in Abergelle international abattoir was calculated based on liver condemnation and was 15,252 ETB loses from liver condemnation annually. Furthermore, out of 1000 snails collected and identified 356 (35.6%) Lymnaea spp, 347(34.7%) Biomphalaria spp and 297(29.7%) Bulinus spp were identified. Trematodes are still major limiting factors to livestock production and productivity in the study areas. So an urgent implementation of control methods including, improving access to clean drinking water for both animals and humans and creation of awareness to cattle owners on the impact of the diseases is necessary. In addition creation of attitude to the farmers in the treating of their animals by using recommended anti-helminthic drugs rather than traditional treatments is mandatory.
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
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.
Study on Basic Heamatological Serum Biochemical and Parasitological Parameters in Exprimentally Sheep by Differnt Infective Doses of Haemonchus Contortus(L3)
(Addis Ababa University, 2008-06) Ashine, Fantu; Hailu, Yacob(phD)
Astud to assess Changes in Haematological Serum Biochemical
Studies on Bovinne Trypanoso Mosis and therapeutic Efficacy of Selected Trypanocidal Drugs in Birbir Valley of Gawo Dalle District West Oromia
(Addis Ababa University, 2008-06) Terfa, Waktole; Hailu, Asrat
Across Sectional Study Was Carried out to Determine the Prevalence of Bovine
Studies on Bovine Trypanosomosis and Efficacy of Selected Trypanocidal Drugs in Konso District, Southern Ethiopia
(Addis Ababa University, 2008-06) Ayledo, Gewado; Ashenafi, Hagos
Studies on bovine trypanosomosis and efficacy of selected trypanocidal drugs involving field and experimental investigations were undertaken inK onso district, southern Ethiopia, from September 2007 to April 2008, with views to determine the prevalence a nd socioeconomic impacts of bovine trypanosomosis; assess the efficacies of selected trypanocidal drugs; and evaluate the propensity of Konso community to devote public resources to integrated tsetse/trypanosomosis control approaches. Questionnaire interviews, cross-sectional and experimental study designs were applied to collect relevant information. A structured questionnaire was designed and posed to randomly selected households and key informants to identify areas with high suspicion of drug resistance. Questions addressed main issues like: herd structure and major livestock health problems; socioeconomic impacts of trypanosomosis; the sources, usage pattern and suspected failure of trypanocidal drugs, etc. Open-ended and close-ended questionnaire interviews were administered to randomly selected households to evaluate the propensity of the community to a holistic integrated disease control. In order to identify areas with high trypanosome infection pressure and risk of drug resistance, initial prevalence study was conducted in representative sample of cattle by examination of monthly blood samples through micro- haematocrit centrifugation and Buffy coat methods. The relationship between parasitological prevalence of trypanosomal infections and herd mean pev was im·estigated through haematological examination during the rainy and dry seasons. In order to assess the therapeutic and prophylactic efficacies of the common trypanocidal drugs, ten zebu calves (Bos indicus) were experimentally infected with randomly selected field isolates of T. congolensc and, when parasitaemic, treated with Diminazene aceturate and Isometamidium chloride at dose rates of 3.5 and 0.5 mglkg body weight. respectively. Experimental animals were monitored for clinical and parasitological parameters on regular basis for over three months. The study results revealed trypanosomosis to be a major threat to livestock production with contrasting arrays of socioeconomic impacts; significant reductions in cattle production losses after tsetse control and a corresponding rise in mean holdings of draft oxen and use of animal traction over the same period: an indiscriminate use and increasing tendencies in mean annual expenditure on trypanocidal drugs at the household level. Contingent valuation study disclosed animus propensity of VI integrated tsetse/trypanosomosis control; household SIze, wealth status and educational background of household heads to be the major determinants influencing willingness to support disease control. Cross-sectional study suggested an overall prevalence of 17.8 % and 14.2 % during rainy and dry season, respectively, reflecting its significant temporal and spatial variation (p< 0.001); and T congolense to be a dominant trypanosome species hampering livestock subsector in Konso district. Regression analyses on haematological findings disclosed a significant reduction (p<0.05) in the herd mean rcv with an increase in the prevalence of trypanosomosis; and that the reduction in herd rcv was significantly higher during dry season than in rainy season (p<0.001), suggesting that trypanosomosis is less-well tolerated during dry months. Results of drug sensitivity testil1g revealed the presence of T congolense populations exhibiting resistance to Diminazene aceturate and, possibly to Isometamidium chloride. In conclusion, the absence of improved veterinary service and indiscriminate use of poor-quality trypanocidal drugs have proven to boost the risk of drug resistance in Konso district. In light of the high likelihood of trypanocidal drug resistance in Ethiopia, the present findings could be a useful tool to improv~ trypanocidal drug usage strategies in the field, and could form baseline information to undertake holistic assessments of drug resistance across tsetse-infested areas of Ethiopia. It is recommendec that integrated disease control approaches be adopted with chemotherapy restricted to clinicall: sick animals, and legislations be devised and harmonized to ensure the quality of trypanocid2 drugs. Keywords: Community participation; Drug resistance; Integrated approach: Sensitivity te~ Southern Ethiopia; Livestock; T congolense; Trypanocidal drugs.
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.
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 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.
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.
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.
STUDY ON IN VITRO LOUSCIDAL AND ACARICIDAL PROPERTIES OF CALPURNIA AUREA, OTOSTEGIA INTEGRIFOLIA, NICOTIANA TABACCUM AND JATROPHA CURCAS AGAINST BOVICOLA OVIS AND AMBLYOMMA VARIEGATUM
(2015-06) Sisay, Alemu; Dr. Yacob Hailu, Dr. Getachew Terefe; Dr. Mirutse Giday; Dr. Ahmed Yasin
The present study was designed to evaluate the preliminary phytochemicals present in methanolic leaf extracts of Calpurnia aurea, Otostegia integrifolia, Nicotiana tabaccum and petroleum ether seed oil extract of Jatropha curcas and to assess their in vitro louscidal and accaricidal efficacy. Accordingly, each plant was subjected to qualitative phytochemical screening for the presence or absence of secondary metabolites such as alkaloids, steroidal compounds, phenolic compounds, flavonoids, saponins, tannins, phlobatannins, triterpens and glycosides using standard procedures. The four selected medicinal plants and a commercially used acaricide (0.1% diazinon) were examined for their louscidal and acaricidal activity against B. ovis and A. variegatum at different time intervals using the in vitro adult immersion test at concentrations of 200, 100, 50, 25, 12.5 and 6.25 mg/ml. The findings revealed that extracts of C. aurea leaf and J. curcas seed oil caused high mortalities of B. ovis at all concentrations with no significant difference from the activity of 0.1% diazinon ( > 0.05) within 24 hours of exposure. Moreover, at 200 mg/ml concentration, crude extracts of N. tabaccum and O. integrifolia produced 93% and 63% mortality respectively against B. ovis within 24 hours of exposure. The extracts of all four plants were also examined for their acaricidal activity against A. vareigatum. Although, the effects of the extracts on this tick species was much lower than what was observed on lice, the extracts of C. aurea leaf and J. curcas seed oil have shown 56% and 39% mortality at 200 and 100 mg/ml concentrations, respectively within 24 hrs exposure of the parasite and was comparable to the acaricidal activity of 0.1% diazinon ( > 0.05). A similar situation was caused by crude extracts of N. tabaccum which was 44% and 39% mortality at concentrations of 200 and 100 mg/ml within 24 hrs of exposure, respectively. However, O. integrifolia showed significantly lower acaricidal activity ( < 0.05) when compared to the reference drug (0.1% diazinon). The current study revealed that crude extracts of C. aurea leaf and J. curcas seed oil have strong louscidal activity. Moreover, crude extracts C. aurea and J. curcas showed high mortality at lower concentrations and can be used as a potential alternative to synthetic acaricides to control B. ovis infestations. Though, they are not effective at lower concentrations, crude extracts of C. aurea, N. tabaccum and J. curcas seed oil had better acaricidal effects on cattle ticks at higher concentrations. This is a promising finding to have an alternative means of treatment to substitute the use of synthetic drugs which have a widespread drug resistance especially in developing countries including Ethiopia. xiv Therefore, further investigation should be made on their safety and in vivo efficacy as well as cost effectiveness of the products that exhibited strong louscidal and acaricidal activity with a view of substituting the conventional synthetic acaricides.
TRYPANOSOMA VIVAX FROM TSETSE INFESTED AND NON-TSETSE INFESTED AREAS OF NORTHWEST ETHIOPIA: INVESTIGATION ON PATHOGENICITY AND DRUG RESISTANCE
(2015-02) Shimelis, Dagnachew; Dr. Getachew Terefe, Prof. Bruno Maria Goddeeris; Prof. Dave Barry, Prof. Getachew Abebe
Animal production in Ethiopia accounts for 15-17% of total Gross Domestic Product (GDP) and 35-49% of agricultural GDP. Unfortunately, the development and intensification of livestock productivity is hampered by devastating diseases, including African animal trypanosomosis. The most important trypanosomes, in terms of economic loss in domestic livestock, include: Trypanosoma vivax, T. congolense and T. b. brucei. Trypanosomes are often described as tsetse transmitted, but this is not always the case, with several species evolved for non-vector transmission or mechanical transmission by other flies. In Ethiopia, particularly the Northwest region is affected by both tsetse and non-tsetse transmitted T. vivax, with expected huge impact on livestock productivity. The control of trypanosomosis in Ethiopia relies on vector suppression and trypanocidal drugs, diminazene aceturate (DA) and isometamidium chloride (ISM) being the drugs most frequently employed. Consequently, drug resistance has become a common issue, especially for T. congolense in several areas. Although fragmented reports are available on the prevalence of the disease, attempts have not been done to demonstrate the relative importance of tsetse and non-tsetse transmitted T. vivax in terms of pathogenicity and drug resistance. This is important not only for evaluating treatment responses and to understanding host resistance/tolerance to the infections but also in the design of future vaccines and trypanocides, as well as the selection of hosts for tolerance or resistance to the parasites. Therefore, our study started with a research questionnaire survey, a prevalence study and experimental studies were conducted to assess trypanocidal drug utilization practices, estimate prevalence of trypanosomosis and the consequent pathogenesis and drug resistance status of T. vivax isolates from tsetse-infested and non-tsetse infested areas of Northwest Ethiopia. The questionnaire survey showed trypanosomosis was a significant animal health constraint for 84% (n=84) and 100% (n=100) of the farmers questioned from non-tsetse and tsetse infested areas respectively. Responses on trypanocidal drug utilization indicated that risk factors for the development of drug resistance such as frequent treatment, poor handling and administration of trypanocides are prevalent and treatment failures are common. The investigation of bovine trypanosomosis carried out in the wet season of 2011 and 2012 showed the prevalence varied from 17.59% in 2011 to 25% in 2012 in tsetse infested areas, and the difference was (P < 0.001) significant. Similarly, in non-tsetse infested areas the prevalence varied from 3.85% in 2011 to 5.93% in 2012, but in this case the rise was not significant. T. congolense (75 %) was the most prevalent species followed by T. vivax (20.58%), and mixed infections (4.41%) in tsetse infested areas while in non-tsetse infested areas only T. vivax was detected. For the investigation of pathogenicity and drug resistance against diminazene aceturate (DA) and isometamidium chloride (ISM), two consecutive experimental studies were performed on five different T. vivax isolates which we isolated from the field; three from a non-tsetse infested area and two from a tsetse infested area; in each case young Zebu cattle were experimentally infected with the isolates. Firstly one isolate from tsetse infested area (TT-ETBS1) and one isolate from non-tsetse infested area (NT-ETBD1) were tested. Secondly one isolate from tsetse infested area (TT-ETBS2) and two isolates from non-tsetse infested area (NT-ETBD2 and NT- VI – Summary ETBD3) were tested. In total 94 young Zebu cattle of which 34 for pathogenicity and 60 for drug resistance studies were used to conduct four different experiments in two consecutive experiments. Parameters measured for the investigation of pathogenicity included clinical, haematological, biochemical, cytokine, and gross and histopathological changes over the course of an infection. The result shows that both TT and NT T. vivax parasites caused clinical infection, with parasites appearing in circulation earlier in NT than TT infected cattle. The infections were characterized by reduced feed intake, intermittent pyrexia, undulating parasitaemia, rough hair coat, enlarged superficial lymph nodes, pale mucus membrane, lacrimation, emaciation and dehydration. Less frequently, diarrhea, mandibular oedema, nervous signs and recumbence were observed in both groups of infected animals. The mean packed cell volume (PCV), haemoglobin, total red blood cell and white blood cell counts were significantly lower and mean corpuscular volume (MCV) was higher in infected animals and consequently the type of anaemia observed was macrocytic normochromic in nature. The extent of changes in serum biochemical parameters, except for few cases of differences, infection with T. vivax derived from both tsetse and non-tsetse infested areas initiate similar biochemical changes indicative of significant pathology and there is no difference between parasite origins and the two experimental infections. Upon euthanasia, infected animals showed enlarged and haemorrhagic spleen; swollen and edematous lymph nodes; pneumonic and emphysematous lung; enlarged liver and haemorrhagic lesions on the brain and intestine. Histopathology revealed significant abnormalities characterized by lymphoid hyperplasia of the spleen, interstitial pneumonia, hepatic necrosis, tubulointerstitial nephritis, meningoencephalitis, and lymphoid hyperplasia in lymph nodes. With respect to the cytokine analysis, significant increases in immune cytokine (IFN-, TNF-α, IL-12 and IL-10) secretions were demonstrated in the first experiment among groups infected by both tsetse and non-tsetse T. vivax isolates, as compared with the non-infected group, but no statistical difference was observed between the groups infected with the two parasite types. However, in the second experiment, tsetse adapted T. vivax elicited a stronger immunological response than the T. vivax from the mechanically transmitted population. Concomitant with this observation is that blood parasite load remained low throughout the experimental period in the group TT compared to the NT groups. The drug resistance studies revealed that treatment of infected cattle with the recommend doses of trypanocides showed incomplete parasite clearance, consistent with the occurrence of resistant strains and adding to growing evidence that such resistance may be a problem. Furthermore at higher doses, one isolate from non-tsetse infested area (NT-ETBD2) was confirmed resistant and another one isolate (NT-ETBD3) was suspected for resistance to DA while one isolate from tsetse infersted area (TT-ETBS2) was suspected for resistance to ISM. Summary - VII Generally, T. vivax from the two locations is almost equally pathogenic, parasite appearance in blood is faster and immune cytokine responses for the most part are lower in case of NT isolate whereas trypanocidal drug resistance is prevalent in both areas. Accordingly the following recommendations are forwarded; a) The present findings, reminded us that the impact of T. vivax should not be neglected in both tsetse and non-tsetse infested areas, b) Frequent administration, poor utilization and handling of trypanocidals could be sources of the problem for drug resistance and hence, appropriate corrective measures be taken in both tsetse and non-tsetse infested areas. In addition, further studies on the mechanisms of resistance for T. vivax is essential to monitor drug resistance and identify potential targets for new drugs, c) The early appearance of parasites in blood and lower cytokine responses in non-tsetse T. vivax infected groups needs further investigation from the parasite, vector and host angles.
STUDY ON PREVALENCE OF POULTRY COCCIDIOSIS IN AND AROUND AMBO, WEST SHEWA ZONE, OROMIA REGIONAL STATE, ETHIOPIA
(2014-06) Solomon, Shiferaw; Dr. Dinka Ayana, Dr. Waktole Terfa
A cross sectional study was conducted on poultry coccidiosis of local and Rhode Island breed from October 2013 to February 2014 in and around Ambo town, Ethiopia. The objectives of this study were to determine the prevalence of coccidiosis, to identify species of Eimeria and to assess potential risk factors(breed,age sex and manegment system). The study involved postmortem examination of chickens, mucosal scraping and parasitological examination of oocyst, gross and histopathological examination and identification of Eimeria species. Out of 390 examined chickens 18.7%(73/390) of them were harbor different Eimeria species. Statistically no significant differences p˃0.05 (χ2=0.921, p= 0.337) was noted between young and adult age groups. Additionally there were no significant differences between local and Rhode Island Red breed(χ2= 0.16, P>0.05), management systems (extensive and semi intensive)(χ2= 2.245, P=> 0.05 and sexes(χ2= 3.609, p˃0.05). In the attempt made to identify the prevalent species of coccidian in the study area, five Eimeria species were identified, namely Eimeria. tenella, Eimeria. necatrix, Eimeria. burnette, Eimeria. maxima and Eimeria. acervulina with the prevalence of 60.27%, 15.06%, 9.6%, 1.4% and 1.4% respectively. Eimeria. tenella was the predominant species in the study area. In conclusion, the present study showed that coccidiosis is an important disease of poultry in the study area and further strategy needs to be implemented to reduce the loss due to coccidiosis.
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.
A STUDY ON BOVINE TRYPANOSOMOSIS, TSETSE CHALLENGE AND EFFICACY OF ISOMETAMIDIUM CHLORIDE IN AMARO SPECIAL DISTRICT, SOUTHERN ETHIOPIA
(2008-06) TESHOME, ASSEFA; Dr. Yacob Hailu, Dr. A.K. Basu; Dr. Hagos Ashenafi
Among livestock diseases tsetse-transmitted trypanosomosis, have been incriminated as the predominant elements in the extreme deterioration of animal resources in sub-Saharan region; Ethiopia that holds the greatest potential for expanding livestock production. The part of Amaro special district particularly mid and low land is infested with tsetse fly where animal trypanosomosis is a serious threat to livestock production. Thus the objectives of the present study were: to determine the prevalence and impact of bovine trypanosomosis and seasonal density of tsetse flies; the efficacy of Isometamidium chloride on bovine trypanosomosis. The study was conducted from October 2007 to May 2008 in Amaro special district of SNNPR. The study design involved questionnaire survey, seasonal cross sectional studies of tsetse and trypanosomosis and assessment of Isometamidium chloride therapeutic efficacy. The questionnaire survey indicated that trypanosomosis is an important problem following erratic rain fall affecting the animals and impeding agricultural activity of the area. The entomological survey revealed that Glossina pallidipes species was the only prevalent species along with other biting flies (Tabanids and Stomoxys). The apparent density of flies was significantly higher in the late rainy season 1.62 fly/trap/day,2.37 and 1.6 for G. pallidipes, Tabanids and Stomoxys, respectively than the dry season where the density was 0.66, 1.12 and 1.03, respectively. The tsetse fly account 27 %, of the total fly catch Tabanids 42.6 %, and Stomoxys 29 % during late rainy season and 24.7 %, 35 %, 39.9 % during dry season. In the low lands (<1500 m.a.s.l) the apparent density for G. pallidipes was statistically significant higher (p<0.05) than the mid land areas (>1500 m.a.s.l) in both seasons. The G. pallidipes caught was higher in the bush lands vegetation type followed by grass wood land and altitudinal distribution limit was up to 1550.m.a.s.l. The apparent density of G. pallidipes fly was positively correlated (r=0.147) with prevalence of trypanosomes infection. The parasitological survey of 1136 animals (585 in the late rainy and 551 in the dry seasons) indicated trypanosomosis prevalence rate to be 27.35 % and 13.79 % in rainy and dry seasons, respectively which showed statistically significant difference (p<0.05) between seasons .The higher infection rate found in the low land areas 31.77 % and 15.45 % than the mid land areas 17.32 % and 12.68 % in the late rainy and dry season respectively indicated a statistically significant difference (p<0.05). T. congolense was the dominant species among the trypanosomes and account 61.02 % infection as compared to T. vivax 24.15 %, in the over all infections. The mean PCV value of parasitaemic and aparasitaemic animal was 21.92 % (CI=21.38-22.46) and 27.31 % (CI = 27.00-27.62) where as the over all mean values of PCV xiii was 26.23 % (CI=25.89 -26.45). The regression analysis of herd average indicated that PCV decreased with increasing prevalence of trypanosomes infections with a negative regression coefficient of values (r= -0.31) in both seasons. A statistically significant difference (p<0.05) in trypanosomes infections between different age groups of cattle was also observed. A total of 69 parasitaemic cattle were selected from 3 PAs for therapeutic efficacy of Isometamidium chloride at the dose rate of 1mg/kg bw. Parasitaemia was demonstrated in 8 out of 69 cattle (11.60 %) with in 15 days; 11out of 61 animals (18.03 %) with in 30 days; 9 out of 50 (18 %) with in 60 days and 6 out of 41 (14.63 %) cattle with in 90 days. With in 90 days of post Isometamidium chloride treatment out of 69 animals 34 (49.28 %) relapsed. In the post treatment, T. congolense contributed for 75 %, 81.82 %, 77.78 % and 66.67 % of infections with in 15, 30, 60 and 90 days, respectively. It is evidenced that trypanosomosis is one of the most important problems for agricultural and animal husbandry operations; the situation is getting worse as control and prevention of trypanosomosis is facing challenges due to limitation of vector control activities and the development of drug resistance in Amaro special district, SNNPR.
A STUDY ON ECTOPARASITES OF SMALL RUMINANTS IN THREE SELECTED AGRO ECOLOGICAL SITES OF TIGRAY REGIONAL STATE AND THEIR IMPACT ON THE TANNING INDUSTRY
(2008-06) MULUGETA, YEBEGEASHET; Dr. Yacob Hailu, Dr. Hagos Ashenafi
STUDIES ON PREVALENCE, ECONOMIC AND PUBLIC HEALTH IMPORTANCE OF HYDATIDOSIS IN SLAUGHTERED ANIMALS AT ADDIS ABABA ABATTOIR, ETHIOPIA
(2008-06) KEBEBE, ERBETO; Dr. Girma Zewde, Dr. Bersissa Kumsa
A cross sectional survey was conducted from November 2007 to April 2008 with the following objectives, to determine the prevalence of hydatidosis in food animals slaughtered at Addis Ababa Abattoir, study the effect of risk factors on the prevalence of hydatidosis, evaluate the size, fertility and viability of the cysts, assess the economic losses and the public health significance of the disease. Routine meat inspection procedures was conducted whereby livers, lungs, hearts, kidneys and spleens were visualized, palpated and incised to detect the presence of the cysts. The sizes of the cysts were determined by measuring the diameters in cm. Fertility was evaluated by observing the presence of protoscoleces under the microscope and viability was determined. The annual economic losses were calculated by multiplying the number of annually condemned organs with the current market value of organs. The public health significance was assessed by structured questionnaire survey. Out of the total of 3430 cattle, sheep, goats and pigs slaughtered and inspected at Addis Ababa Abattoir, 639 (18.6 %) had hydatid cysts. Prevalence of 254 (21 %), 206 (19.9 %), 102 (16 %) and 77 (14 %) were recorded in cattle, sheep, goats and pigs, respectively. Prevalence of 132 (20.9 %), 85 (22.4 %) and 37 (18.7 %) was registered in cattle of Borana, Arsi and Abyssinian Zebu breeds, respectively. There was no significant variations by cattle breeds. Even though higher prevalence was detected in cattle from midland areas 124 (21.3 %) than in cattle originated from lowland areas 130 (20.5 %), there was no significant difference in prevalence in cattle from the two origins. The prevalence in cattle were found infected in age of > years old, 125 in age of 4-6 years (49%), and < 2 -4 years old 12 (4.7 %). Prevalence of 88 (8.5 %), 53 (5.1 %) and 65 (6.3 %) was recorded in Black Head – Ogaden, Adal and Abyssinian sheep breeds, respectively. Sheep under less than 1 year 77 (7.4 %) was more infected than sheep above 3 years of age 11 (1.1 %) and the difference in prevalence was significant. The prevalence of hydatidosis in Arsi- Bale and Keffa goat breeds were 53 (8.3 %) and 49 (7.6 %), respectively. The frequency of infection was higher in pigs kept at backyard 55 (10 %) than those managed under intensive husbandry system 22 (4 %). Out of the total 2071 cysts isolated from the different organs of cattle, 1007 (48.6 %) were small, 711 (34.3 %) medium and 353 (17 %) were large. More cysts were counted in the lungs of cattle, sheep and goats, but more cysts were found in swine's liver than in lung. Out of the total of 396 cysts isolated from organs of cattle, 217 (54.8 %) were fertile, 133 (33.6 %) sterile and 46 (11.6 %) were calcified. Out of X the 217 fertile cysts, 185 (85.3 %) were viable and 32 (17.3 %) were none viable. The annual economic loss was estimated to be 10,923,601.00 Ethiopian Birr, which is equivalent to 1,139,061.63 USD. 234 cases of human hydatidosis were surgically treated at the Tikur Anbassa Referral Hospital in Addis Ababa. The economic and public health significance of the disease is discussed and pertinent conclusions are drawn.
STUDIES ON BOVINE TRYPANOSOMOSIS AND EFFICACY OF SELECTED TRYPANOCIDAL DRUGS IN KONSO DISTRICT, SOUTHERN ETHIOPIA
(2008-06) GEWADO, AYLEDO; Dr. Hagos Ashenafi, Dr. A.K. Basu; Dr. Yacob Hailu
Field and experimental investigations on bovine trypanosomosis and efficacy of selected trypanocidal drugs were undertaken in Konso district, southern Ethiopia, from September 2007 to April 2008, with major views to determine the prevalence and socioeconomic impacts of bovine trypanosomosis; assess the efficacies of selected trypanocidal drugs; and evaluate the propensity of Konso community to devote public resources to integrated tsetse/trypanosomosis control approaches. Questionnaire interviews, cross-sectional and experimental study designs were applied to collect relevant information. A structured questionnaire was designed and posed to randomly selected households and key informants to identify areas with high suspicion of drug resistance. Questions addressed main issues like herd structure and major livestock health problems; socioeconomic impacts of trypanosomosis; the sources, usage pattern and suspected failure of trypanocidal drugs, etc. Open-ended and close-ended questionnaire interviews were administered to randomly selected households to evaluate the propensity of the community to a holistic, integrated disease control. In order to identify areas with high trypanosome infection pressure and risk of drug resistance, initial cross-sectional study was undertaken on randomly selected cattle heads the monthly blood samples of which were examined through micro- haematocrit centrifugation and Buffy coat methods. Linear regression model was employed to assess the relationship between parasitological prevalence of trypanosomal infections and herd average PCV. In order to assess the therapeutic and prophylactic efficacies of the common trypanocidal drugs, ten zebu calves (Bos indicus) were experimentally infected with randomly selected field isolates of T. congolense, and treated with Diminazene aceturate (3.5 mg/kg BW) when the first peak of trypanosomal parasitaemia appeared. Based on deterioration in clinical and haematological parameters, relapsed calves were re-treated with Isometamidium chloride (0.5 mg/kg BW). Experimental animals were monitored for clinical as well as parasitological parameters on regular basis for over three months. The study results revealed trypanosomosis to be a major threat to livestock production with contrasting arrays of socioeconomic impacts; significant reductions in cattle production losses after tsetse control and a corresponding rise in mean holdings of draft oxen and use of animal traction over the same period; an indiscriminate use and increasing tendencies in mean annual expenditure on trypanocidal drugs at the household level. Contingent valuation study disclosed animus propensity of Konso community to devote VII both labour and monetary resources to support integrated tsetse/trypanosomosis control; household size, wealth status and educational background of household heads to be the major determinants influencing willingness to support integrated disease control. Cross-sectional study on bovine trypanosomosis indicated an overall parasitological prevalence of 17.0 % and 13.4 % during rainy and dry season, respectively, reflecting its significant temporal and spatial variation (p< 0.001); and T. congolense to be a dominant trypanosome species hampering livestock sub-sector in Konso district. Regression analyses on haematological findings disclosed a significant reduction (p<0.05) in the herd mean PCV with an increase in the prevalence of trypanosomosis; and that the reduction in herd PCV was significantly higher during dry season than in rainy season (p<0.001), suggesting that trypanosomosis is less-well tolerated during dry months. Results of drug sensitivity testing revealed the presence of T. congolense populations exhibiting resistance to Diminazene aceturate. In conclusion, the absence of improved veterinary service and indiscriminate use of poor-quality trypanocidal drugs have proven to boost the risk of drug resistance in Konso district. In light of the high likelihood of trypanocidal drug resistance in Ethiopia, the present findings could be a useful tool to improve trypanocidal drug usage strategies in the field, and could form baseline information to undertake holistic assessments of drug resistance across tsetse-infested areas of Ethiopia. It is recommended that integrated disease control approaches be adopted with chemotherapy restricted to clinically sick animals, and legislations be devised and harmonized to ensure the quality of trypanocidal drugs.
STUDY ON PREVALENCE OF MAJOR GI NEMATODIOSIS OF SMALL RUMINANTS IN THREE SELECTED SITES OF AFAR REGION, ETHIOPIA
(2008-06) DEREJE, SHIFERAW; Dr. Yacob Hailu, Dr. Dinka Ayana

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