Browsing by Author "Yilkal Asfaw"
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Item A Longitudinal Study of Epidemiological occurrence of Antidodies Against Newcastle Disease Affecting Village Indigenous Chickens in Boro and Jarso of Ethiopia(Addis Ababa University, 2012-04-20) Berhanu Abera; Yilkal AsfawA longitudinal study to monitor epidemiological occurrence of antibodies against Newcastle disease (ND) virus, potential risk factors for these occurrence and outbreaks in scavenging village chickens was conducted in eight villages within two districts of Oromia region. A total of 985 blood samples were collected from 800 individual birds in 400 household chicken flocks during two sampling periods. None of the birds enrolled in the study was vaccinated against ND. A haemagglutination inhibition (I-II) test was used to determine antibody titres against ND virus. The bird-level ND seroprevalence pooled across all samplings was 11.1 %, while accounting for each season 10.1 % and 13.8% of wet season and dry season, respectively. The bird-level incidence rate for the period between the first and the second sampling was 4.3%. The flock-level ND seroprevalence (at least one bird tested had antibodies against ND virus) pooled across all samplings was 19.4%. The result indicated that village chickens in Horo and Jarso were exposed to ND virus; there was a higher seroprevalence of infection in Jarso than Horo despite insignificant association either in flock-level or bird-level. Univariant risk factor analyses indicated that flock-level seroprevalence of ND was significantly associated with different market-sheds, villages, offering of rain feed, frequency of contact during wet season, mode of waste disposal, and housing (p<0.05). None of the factors investigated was significantly associated with bird level incidence. Management had significant association with disease outbreak. Thus, despite occurring year round; in current study outbreaks during rainy season were mainly due to management factors and severe at times of climatic stress and had been known to worsen the outcome of the outbreak. The experimental study investigated the effect of concurrent parasitic and viral diseases on the immune response; as well as differences in protection between indigenous ecotype and improved breeds of chickens. This was done using the antibody response towards ND vaccine virus in both chickens ecotypes/breed with and without parasites. Multivariant analysis showed that there was a significant reduction in NDV specific antibody production post vaccination in individuals with parasites compared to antihelmintic treated chicken in both breeds. However, this finding confirmed that there was a significant dramatic reduction in NDV specific antibody production post vaccination in indigenous ecotype compared to improved breeds (p< 0.05). Though breeds differ genetically in their immune responsiveness to the antigen, and being protected following challenge; difference in their susceptibility to the virulent challenge virus needs to be ruled out.Item African Horse Sickness Study on Seroprevalence and Identifications in Equidae at Selected Sites in Ethiopia(Addis Ababa University Faculty Of Veterinary Medicine, 2006-06) Kassa Demissie; Yilkal AsfawABSTRACT A study was undenaken to determine the seroprevalence o f Afri can horse sick ness viru s antibod ies, isolate and characterize th e vi ru s re sponsible as well as identi fy potenti al risk facto rs in t he equi ne po pulation of sel ected study areas in Ethio pia In total 1265 seru m samples origina t ing from 824 donkeys, 383 horses and 58 mules were coll ected from September 2005 to mid of April 2006. Comp eti tive Enzy me Linked Immu nosorbent Assay (C-ELISA) configu rati o n was employed to dete rmine the presence of AHSV antibodies The apparent prevalence of AHSV was found to be 297% (95% C I ~ 26.8-33 .0) in donkeys, 104% (95% C I ~ 78- 14 .0) in ho rses and 103% (95% C I ~4 . 8 -22 I) in mules The overall apparent sera prevalence of AJ-I SV was found to be 23% (95% C I~20 8-25 4) There is sig nificant variat ion amongst the types of equidae in seropositivity (PItem African Horse Sickness: Study on Seroprevalence and Dentification of Risk Factors in Equidae at Selected Sites in Ethiopia(2006-06) Kassa Demissie ; Yilkal AsfawA study was undertaken to determine the seroprevalence of African horse sickness virus antibodies, isolate and characterize the virus responsible as well as identify potential risk factors in the equine population of selected study areas in Ethiopia. In total 1265 serum samples originating from 824 donkeys, 383 horses and 58 mules were collected from September 2005 to mid of April 2006. Competitive Enzyme Linked Immunosorbent Assay (C-ELISA) configuration was employed to determine the presence of AHSV antibodies. The apparent prevalence of AHSV was found to be 29.7% (95% CI = 26.8-33.0) in donkeys, 10.4% (95% CI = 7.8-14.0) in horses and 10.3% (95% CI =4.8-22.1) in mules. The overall apparent seroprevalence of AHSV was found to be 23% (95% CI=20.8-25.4). There is significant variation amongst the types of equidae in seropositivity (P<0.05). Statistically significant (P<0.05) difference in seroprevalence was observed in the different study areas, confirming the existence of agro-ecology based variation in the occurrence of African horse sickness. The highest seroprevalence of AHSV was documented in the lowlands followed by midland and highland areas. This has direct correlation with the ecological distribution of the Culicoides vectors. As for age dependent variation in seroprevalence no statistical significant difference was found. All age groups as well as male and female populations were equally affected. The risk of acquiring AHS is more than two fold (OR = 2.1) with respect to the types of equidae affected. Moreover, agro-ecology contributes nearly two fold (OR =1.5) for the occurrence of African horse sickness. There is strong association among C-ELISA result of AHSV antibodies, types of equidae and agro-ecology, but age is not part of the interaction. However, sex has weak effect to precipitate the occurrence of African horse sickness. Active disease search was conducted with the aim of virus isolation and identification. After three blind passages were carried out on vero cell lines the sample was subjected to I-ELISA configuration. However, the result was negative. In the presence of the disease in the field with classical pathognomonic signs and postmortem lesions the negative result is probably due to the improper handling of the tissues processed. The indigenous knowledge base of equine owners about African horse sickness in the study areas was assessed through a structured questionnaire format. The survey result indicated that, the indigenous knowledge of owners was found to be unsatisfactory.Item Epidemiological Study of Foot ond Mouth Disease in Cattle and Small Ruminants In Selected Districts of Gambella Regional State, South-West Ethiopia(Addis Ababa University, 2010-04-30) Belachew Tefera; Yilkal AsfawA cross sectional study based on serological and questionnaire survey was conducted in 4 selected Districts of Gambella Regional State from September 2009 to April 20 I 0 to determine the sero-prevalence of FMD, the involvement of small ruminants in the epidemiology of FMD, identify and characterize the serotypes of FMD virus circulating in the study area and assess epidemiological risk factors associated with FMD in cattle. A multistage random sampling was implemented to select the required sample size. Field observation, clinical examination, specimen collection and laboratory diagnosis, interviewing farmers, and reviewing secondary data source were methods followed to generate information. Sera were tested by 3ABC-ELISA at NAHDIC, Sebeta and FMD virus identification and characterization was canied out at Pirbright, UK. Results were analyzed using descriptive statistics, chi-square test and logistic regress ion. The overall seroprevalence of FMD was 12% (N = 1,152) for cattle and 1.43% (N = 768) for small ruminants. Cattle was 9.37 times more FMD seropositive than small ruminants. Seroprevalences of 17.74%, 11.86%, 9.42% and 8.97% were recorded in Hang, Gambella, Abobo and Lare Districts, respectively. The difference among which was statistically significant (p<0.05). From the different risk factors analysed; herd size, age, contact with wildlife and cattle-small ruminant combination were significantly associated with FMD seroprevalence (p<0.05). From the total of 338 cattle and 69 small ruminants clinically examined during an outbreak episode 124 (36.69%) of cattle showed signs and lesions suggestive of FMD but observable symptoms were not detected in small ruminants. FMD virus SAT-2 serotype was responsible for the OCCllnence of the investigated outbreak in the study area. The field isolates shared greater than 80% genetic similarity with the Benshangul-Gumuz and Sudan SAT-2 isolates. The present SAT-2 isolate had also showed antigenic relationship with the vaccine strains of Eritrea SA T2IERI and Zimbabwe SAT2/ZIM Crl-values > 0.3 and 0.4 for VNT and LPB-ELISA), respectively. Questionnaire survey feedback generated from a total of 120 respondents indicated that FMD was prevalent and frequently affect the cattle population of the study area. Herd congregation sites, free animal movement, seasonal recurrence of flood and infected animal inlToduction into herd were complained as possible source of FMD infection and dissemination. This work generates preliminary baseline information on ClIITent status of FMD along with associated risk factors in the study area in particular and can also add information nationally on existing knowledge in general. Therefore, the identified FMD virus SAT-2 serotype should be considered in vaccine formulation, cattle and small ruminants must be surveyed regularly, domestic animals should be protected from wildlife park entry and realizing regional approach of FMD control program with the neighboring regional states and the Sudan republic across the border is recommended.Item Epidemiology and Economic Importance of Fasciolosis of Domestic Ruminants in Selected Sites of Tigray Regional State, Northern Ethiopia(2008-06) Gebru Legesse; Yilkal AsfawA cross sectional study was conducted to determine prevalence, assess risk factors associated with fasciolosis and evaluate economic losses in four selected areas of Tigray Regional State, during September 2007 to May 2008. A total of 1736 domestic ruminants comprising of 1015 cattle, 526 sheep, 167 goats and 28 camel were subjected to coprological investigation and 236 slaughtered animals were included for post mortem survey. Based on coprological investigation the overall prevalence of fasciolosis was 25.3%, 35.7%, 11.4% and 3.6% in cattle, sheep, goats and camels, respectively. In the slaughterhouses survey the prevalence of fasciolosis was 33.1%, 37.2%, and 17.6% in cattle, sheep and goats, respectively. High prevalence was recorded in sheep (37.2%) and lowest in goats (17.6%). Statistical significant differences was observed in prevalence among the species (p<0.05) using coproscopy. Fasciola hepatica was dominant in the highlands while the dominant species in the midland and lowland was F. gigantica. Differences in agroecology, season, body condition and age were shown to have associations with prevalence while no significant association was observed between sexes of animals. Species of animals, season, age and agro-ecology were known to be among important risk factors associated with fasciolosis. The direct and indirect economic loss incurred due to fasciolosis in the study area was estimated to be 268,536.21 Ethiopian Birr. Out of the total incurred losses, 86.3% was in cattle. The present study revealed that infection of domestic ruminants by Fasciola species was attributed by the presence of favorable environment for the abundance of intermediate host and the parasite, hence requiring immediate strategic intervention against the disease.Item The Epidemiology of Bovine Brucellosis in Intra and Peri-Urban Dairy Production Sysems in and Around Addis Ababa(Addis Ababa Universty, 1998-01) Yilkal Asfaw; Baykyegn MollaBovine brucellosis is an infectious disease of economic importance by causing abortions and infertility. Bovint: brucellos is considered a zoonosis infprmation on the extent of bovine brucellosis. however. is scarce for the expanding intra- and peri- urban dairy enterprise in Ethiopia. The purpose of this study was to investigate the status of bovine brucellosis and its impact on reproduction in some intra- and peri-urban dairy production systems in Ethiopia. A cross-sectional investigation of bovine brucellosis was carried out from Jun to October 1917 on -42 dairy farms located in Debre Zeit, Kalili, Sebela, and Addis Ababa. The farms represent peri-urban systems. Intra-urban systems in secondary towns and intra-urban production systems. Bulk milk samples were collected from each farm (herd ) in June, August, and October Blood samples from 950 non-vaccinated breeding animals above six months of age were collected once in June. The milk Ring Test (WRT), the Rose Bengal Plate Test (ROPT). and the Complement Fixation Test (CFT) were carried out on milk and serum samples. Farm management parameters and zoonotic aspects were cullected by administering a questionnaire . An overall herd infection rate of 33.3% was determined. With respect to the production systems 100%. 30%, and 12.5% of the farms were infected in peri-u rban. intra.-urbun stecondary town. and intra -urban systems, respectively. The within herd prevalence ranged from 0-16.7%. At least one or two reactors were idemilied in 64.3% of the farrms. An overall prevalence rate of 811% was found on individual animals. A prevalence rate of 9.8 % was observed in the age group 2 to 4 years. A prevalence rale af 9.1 % and 3.3% was identified in fams that keep more than 100 animals, and less than 50 animals, respectively. Significant difference in prevalence rate was observed in animals aged below and above 2 yeas and between no arturition and at least one parturition. A significant difference in prevalence rate was also observed between farms that keep below 50 and above 100 animals. Odds ratios (OR) of 2.1 4 (1.04·483) between age and brucellosis infection and 2.99 ( 1.29· 8.06) between herd size and brucellosis infection were determined. Significant differences in prevalence rates were not observed among the production systems and districts in indvidual animals. Agreement (kappa values) between RBPT +/'CFT+ and MRT tests were 0.31 (first MRT result ), 0.43 (first and second MRT results pooled), and 0.58 (first. second and third MRT results pooled). Moderate agreement (k=0.44) was found between RBPT+ and CFT +and good agreement (k=O.74) was found between RBPT+ and RBPT +ICFT + testing procedure Considering positive results in both RBPT and CFT as gold standnrd the sensitivity (SE) and specificity (SP) of the pooled MRT were 57.1% and 89.3%respectively). Sensitivty and specilicity, of RBPT were 100% and 94.6%. respectively. Associations betweer reproductive and production parameters and brucellosis infection could not be established for individual animals. However. on the basis of questionnaire .answers, previous abortions and use of natural service were associated with Brucellar infection: OR of 15.58 (1.72-79.16) and 0.06(0·0.61) were calculated respectively·. Abortions were recorded in 56.1 % of the farms. Lack of knowledge of brucellosis was recorded in 87.8% of the farms. Cleaning and disinfection was done regularly in 29.3,% removal of infected animals was farm practice in 14.6%provision of maternity pens was found in 4,9% of the farms, and 21.9% of the farms obtained repbcement stock from outside source. Prokmged fever was observed in nine persons interviewed . They were attending cows for at least six months. Absence of vaccination . herd size, cuttle density, lack of knowledge of brucellosis, and nonmanagement and husbandry practices are likely factors responsibl to explain the relaively high prevalence rate observed in his study. Due to its impact on production and lfor its 'Zoonotic significance. Awareness of brucellosis in urban farming should be given priority. Conclusions and recommendations in this regard, emphasizing control of brucellosis are given.Item The Epidemiology of Bovine Brucellosis in Intra-and Peri- urban Daban Dairy Production Systems in and around Addis Ababa(Addis Ababa University Faculty Of Veterinary Medicine, 1998-01) Yilkal Asfaw; Bayleyegn MollaBovine brucellosis is an infsease of economic importance by causing abortions and infertility .Bovine brucellosis is considered azoonosis information on the extent of bovine brucellosis . however, is scarce for the expanding intra- and peri- urban dairy enterprise in Ethiopia .the purpose of this study was to investigate the status of bovine brucellosis and its impact on reproduction in some intra and peri – urban dairy production systems in Ethiopia across- sectional investigation of bovine brucellosis was carried out from june to October 1997 on 42 dairy farms located in debre zeit ,kaliti, Sebeta .and Addis AbabaItem Hematological and Serological Response of Some Chicken Types at on Station to Newcastle and Marek's Disease Vaccination(Addis Ababa University, 2011-06) Edilu Jorga; Reta Dliguma; Teshalc Sori; Yilkal AsfawI\n experimental study on five Ethiopian chicken ecotypes namely Jarso, Tepi , Chere, Arsi and Horro and other two chicken breeds (Fayoumi and 130vans) was conducted from December 2010 to June 20 11. Total of 260 chickens among which 70 Cheick. 40 Jarso. 2 1 Lorre, 9 I\rsi. 30 Tepi. 20 Bovans and 70 Fayoumi chickens were included in the study. The objective or the study was to evaluate the responses of different chicken types to Marek's and Newcastle disease vaccination through hematological profile, serum protein profile and antibody titer. Day old chicks 01' each ecotype were randomized in to two groups one for Marek's disease (MD) vaccination and the other remain unvaccinated while all or them vaccinated against Newcastle disease vaccine (I .a Sota strain) on 21 st, 5O'th and 120'h day after hatching. Three round blood sample was collected at age or day 3S, 65 and 105. For serum protein analysis and hemaglutination inhibition (III) antibody titer test three round serum sample was collected on 3S'h 6S'h and 135,h day each following fifteen days after vaccination with Newcastle disease vaccine. IA cording to the current study the total leukocyte, lymphocyte and monocyte count was found to be higher for Fayoumi and minimum count was observed for lorry chicken. Heterophil, eosinophil and basophil count was higher in Arsi chicken. Hi ghost packed cell volume (PCV) value (361.3.9) was observed in I:ayoumi chicken whereas maximum value' or hemoglobin concentration (9.002+.97) was in I\rsi chicken. The comparison or MD vaccinated to nonc vaccinated chicken reveled higher val ues of all counts and I'CV revaccinated but lower hemoglobin concentration. Lymphocyte count was found to increase with time (age) while others either decrease or no clear pattern. On the other hand, the HI titerl'or Newcastle was compared and Jarso and Fayoumi were found to be superior over the other chicken types whereas Bovans, Tepi and 1-IOiTO were with lower titer. The trend for total protein was increasing far Jarso, Tepi and Arsi and the values in these ecotypes were higher. This study generally loud that the chicken types involved were or a wide diversity in their response to Marek's and Newcastle vaccination which was reflected by the difference in hematological. serological and total protein values in responses to vaccination. Key words: Chicken types, hemagglutination Inhibition. Climatological profile, Immune response, Marek '.I' disease, Newcastle disease, prolamin profile, vaccinationItem I Ddis Ababa University Faculty of Veterinary Medicine Sero – Epidemiology of Brucellosis in Small Ruminants in Southern Ethiopia(2007-06) Mengistu Mekuria; Yilkal AsfawA cross sectional study was conducted in Oromia and Regional state of SNNPRS from August 2006 to April 2007 to determine the prevalence of brucellosis in goats and sheep and areas associated risk factors using mRBT and CFT. A total of 2905 goats and 1059 sheep were included in this study. The modified Rose Bengal Test (mRBT) prevalence rate in goats’ over all is 5.5% (n=2905) while in sheep is 4.0% (n=1059) and total in small ruminants 5.1% (n=3964) in extensive farming system. The mRBT positive rates, in relation to production systems are 7.11% and 0.5% in pastoral and sedentary respectively. In the intensive farming system, in Adami Tullu Agricultural Research Center, no sero-positive animals while in Awassa Agricultural College, the prevalence rate is 20% by mRBT. The serial test positives (mRBT and CFT) prevalence rate in goats is 3.2% (n=2905) while in sheep is 1.6% (n=1059). The small ruminants’ prevalence rates are 3.9% and 0.33% in pastoral and sedentary production systems respectively. In the intensive farming system, in Adami Tullu Agricultural Research Center, no sero-positive animals while in Awassa Agricultural College, the prevalence rate is 18.4 % by serial tests. Risk factors analysis was carried out in relation to production system, species and sex and significant differences were observed to counter categories (p<0.05). Age factor showed no significant difference in this analysis, which may be due to low number of observations at higher ages. xii Flock prevalence was determined only in pastoral production system, but not in mixed crop livestock production system because of small holdings and difficulty to consider as herd (flock). Herd (flock) prevalence was observed only in pastoral production system. Herd prevalence by serial test in Borerna (Oromya) is 38.8 %( n=73), while in South Omo and Konso (SNNPRS) is 22.7 %( n=75). The cut-off value for flock prevalence was greater or equal to one. In general brucellosis in small ruminants is prevalent in the low land pastoral production system at individual and herd level. In the sedentary areas at higher altitude the prevalence is 0%, except in some fringed areas bordering the pastoral production system as in konso district. Based on the result of the study concluding remarks and recommendation are forwarded.Item Investigation of Foot and Mouth Disease Outbreaks and Assesment of Risk Factors in Oromia, Amhara and Southeren Nations, Nationalities and Peoples (Snnp) Regional States of Ethiopia(2008-06) Yoseph Legesse; Yilkal AsfawSeven foot and mouth disease outbreaks were investigated in Oromia, Amhara and SNNP regional states of Ethiopia, November2007 to March 2008. The objective of the study was to determine the epidemiological characteristics of FMD outbreaks and to assess the associated risk factors. Morbidity rates ranging from 22.14 (Torben ashe) to 47.56 (DZARC) and mortality rates 2.33 (Coca) to 0.61(DZARC) were observed. Two viral serotypes namely O and SAT1 were isolated from tissue and oesophageal-pharyngeal (OP) fluid samples submitted to WRL, Pirbright. The isolation of the later serotype (SAT1) is the first of its kind in Ethiopia. Clinical, serological and virological evidences have shown that small ruminants are readily affected by FMD. However, there was a highly significant difference between cattle and these species in manifesting the characteristic clinical signs of the disease, being sub clinical in shoats. Additional risk factors were host characteristics like age and breed of cattle. Morbidity and mortality rates were higher for younger (<2years) and lower for older (>4 years) cattle. Age specific morbidity rates were 46.37% and 27% for these two age groups in Chigit and mortality rates were 8.7% and 1.5% for cattle of the same category in Coca outbreak. In DZARC farm breed specific morbidity rates were 68.4% and 0% for crosses and Borans respectively. Thus susceptibility to FMD varied with species, age, breed and type of viral serotype involved. Furthermore, the absences of working control policy, lack of livestock movement control, involvement of various hosts and the high rate of contact at communal points were found to be the major risk factors of FMD in Ethiopia. The present situation of FMD in Ethiopia requires an immediate intervention. Therefore, implementation of a profound control strategy involving livestock movement control, strategic vaccination of specific risk groups, consideration of SAT1 serotype, and further investigation on potential risk factors was recommended.Item Outbreak Investigation and Molecular Epidemiology of African Horse Sickness Virus Circulating in Central, Eastern and Southern Parts of Ethiopia(Addis Ababa University, 2011-06) Nigatu Aklilu; Yilkal Asfaw; Esayas Gelaye; Gelagay AyeletThis study was conducted from September 2009 to December 20 lOin central, eastem and western patts of Ethiopia to investigate and identify circulating serotypes of African horse sickness virus (AHSV). A total of ten outbreaks were investigated in the study period. Samples collected for virus isolation and identification were whole blood in ethylene diamine tetra-acetic acid (EDTA) from diseased horses and mules, and tissues from freshly dead horses. AHSV isolation on Vero ce ll line and detection of AHSV genomes using conventional RT-PCR were archived in the National Veterinary Institute (NY!) molecular laboratory, Debre Zeit, Ethiopia. Samples were sent for further viral isolation, identification, sequencing and phylogenetic analyses in the Non-vesicular Laboratories of Institute of Animal Health (!AH), Pirbright, United Kingdom (UK). A total of 336 sera were collected from apparently healthy equids that were either unvaccinated or have vaccination history of before three years in Cheat and Tikur Inchini districts and subjected to a serological test using a commercialized blocking enzyme linked immunosorbent assay (ELISA) kit. A questionnaire survey was administered to 178 equine owners and retrospective data of outbreaks for three years obtained from Animal and Plant Health Regulatory Directorate (APHRD) in the Ministry of Agriculture (MoA) were analyzed to see the national picture and seasonality of outbreaks. A total of 48 horses died of African horse sickness (AHS) during the outbreaks. Ada'a district was the major outbreak site where the outbreak involved a number of towns and villages. A total of 81 horses and 3 mules were affected and 46 (54.8%) of them demonstrated cardiac form of the disease while the rest 30 (35.7%), 6 (7. 1%), 2 (2.4%) were affected by horse sickness, pulmonary and mixed forms of AHS, respectively. Multiple serotypes of AHSVs were identified from the submitted samples by quantitative real-time RT-PCR and sequencing. AHSV-4, AHSV-6, AHSV-8 and AHSV-9 serotypes were identified. Identification of A HSV -4, AHSV -6 and AJ-ISV -8 are reported for the first time in Ethiopia. AJ-ISV -9 was the dominant serotype circulating in the outbreak areas. Serotypes identified from the outbreaks were phylogenetically compared with the reference stains in IAH, Pirbright, UK. A total of 147 (43.8%) of the sampled equids were found seropositive for antibodies against AHSV. The respective seropositivity of equids in Cheat and Tikur Lnchini districts were 49.4% and 37.8% (p= 0.032). Statistically significant difference was not observed between risk factors of species, age and sex (p > 0.05). From the total 178 respondents 71 (40%) of them indicated that their indigenous knowledge on the disease, its transmission and control measures is unsatisfactory while the rest (60%) were aware of the disease. Local names used for AJ-IS were 'Derbetu ' or 'Dibe Ferda ' in Tikur Inchini and 'Horyo' in Cheta. Locally known equi ne flies were 'Bombisa ' in Tikur lnchini and 'Gemo' and 'Yubo' in Cheta. A total of 482 outbreaks were recorded retrospectively from Oromia (80.1 %), Amhara (10.6%), Southern Nati on Nationalities and People 's Regional State (SNNPRS) (7.7%) and the rest from Tigray, Dire Dawa and Afar regional states. AHS outbreaks were more frequently observed fi·OI11 September to December and the highest number of outbreaks was reported in 2008. Generally, the identification of multiple serotypes in the Crrnent study indicated increased risk and devastating outbreaks of AHS is a possibility. The production of polyvalent vaccine which confers protection against the identified serotypes and prophylactic vaccination of horses and mules are recommended. Key words: African horse sickness virus, equine, Ethiopia, outbreak, RT-PCR, serotype.Item Prevalence of Bovine Mastitis in Lactating Cows Among Small Holder Dairy Herds and Antimicrobial Sensitivity Test on Major Isolated Pathogens in and Around Gondar(2007-06) Nibret Moges; Yilkal AsfawA cross _ sectional study was conducted on 322 local and crossbred lactating hand milked small holder cows in and around Gondar from September 2006 to March 2007 to determine prevalence, the causal agents of infection, associated risk factors and tests susceptibility to drugs using California Mastitis Test, clinical inspection of udder, and bacterial culture. Of the total cows examined, 32.6% (322) had mastitis, 0.93 % (3) was clinical and 31.67% (102) sub clinical mastitis. Out of 1249 quarters examined 164 (13.13%) were found to be infected, 7(4.27%) clinically and 157 (95.73%) sub clinically from 1288 quarters examined 39 (3.02%) were blind. Clinical prevalence at cow level was 0.93% in crossbreds and none in local zebu breeds. Sub clinical mastitis at cow level based on CMT was 28.57% in crossbreds compared to indigenous zebu 3.10% (P<0.05). Quarter sub clinical prevalence based on CMT was 16.05% and 5.12% for crossbreds and local zebu, respectively. Among potential risk factors considered breed, age, parity and stage of lactation were found to affect the occurrence of mastitis significantly (p< 0.05). The prevalence of mastitis was significantly higher in Holstein _Friesian crossbreds than indigenous zebu, in the early lactation stage than in the mid lactation stage. Of 176 CMT and clinically positive udder quarter samples analyzed microbiologically 164 were culturally positive for known mastitis pathogens and 1085 were negative. Of the 164 positive samples isolation rate of Staphylococcus aureus 16.5%, Coagulase negative Staphylococci 31.1%, Streptococcus agalactiae 15.9%, Streptococcus dysgalactiae 14.0%, Streptococcus uberis 6.7%, Micrococcus spp 7.3%, Corynebacterium bovis 2.4%, Actinomyces pyogens 1.2%, Bacillus cereus 0.6% and Escherichia coli 4.3%. Staphylococcus aureus, Coagulase negative Staphylococcus, Streptococcus agalactiae, Streptococcus dysgalactiae, Streptococcus uberis, Micrococcus species, Corynebacterium bovis, Actinomyces pyogenes, Bacillus cereus and Escherichia coli were isolated from cases of sub clinical mastitis. Generally, it was found that Sulfisoxazole was the most effective antibiotic VII where 91.07% of the total isolates were found susceptible, followed by clindamycin and kanamycin (89.3%), (88.4%) The least effective antibiotics were streptomycin (45.5%) and ampicillin (49.1%). Tetracycline, erythromycin, chloramphenicol, oxacillin, 65.2%, 59.8%, 64.3%, 58.04% respectively, were categorized as drugs of weak efficacy. Inadequate sanitation of dairy environment, poor animal health services and lack of proper attention to health of the mammary glands were important factors contributing to high prevalence of mastitis. Some recommendations were forwarded to reduce the tend of mastitis in the study area.Item Seropreva Alence Study of Brucellosis in Cattle and Human in Bahirdar Milkshed(AAU, 2005-06) Mussie Hailemelekot ; Yilkal AsfawA Cross – Sectional Study Was Conducted In South Gondar, West Gojjam And Awi Zones of Amhara Regional State, Between October 2004 And March 2005, to Determine the Sero – Prevalence of Brucellosis in Cattle and Humans as Well as to Identify the Likely Potential Risk Factors. Two Sage Cluster – Sampling Was Employed, by Which 11 towns as Identified Primary Units and 195 Farms as Secondary Units in Semi – Intensive Production System. Similarly, 29 Peasant Associations as Primary Units and 145 Individual Cattle Owners as Secondary Units Were Selected for the Extensive Production System. in the Government Cattle Breeding Ranch all Eligible Cattle Were Sampled. Human Risk Groups Were Sampled Using Purposive Sampling Method. the Study Methods Involved Collection Serum Sample, Data, Questionnaire Surveys and Serological Tests Conducted in Laboratoris. Accordingly, 1944 Cattle (341 Clusters in the Three Production Systems)Were Sampled. the Sampling Involved all Cattle Above 6 Months of Age With No History of Previous Vaccination Against Brucellosis. the Number of Cattle Sampled in Extensive, Semi – Intensive and Ranch Were 864, 754 and 326, Respectively. the Types of Tests Used to Detect the Presence of Brucella Antibodies Were Rose Bengal Plate Test (RBPT) as Sereening Test, and Complement Fixation Test (CFT) as Confirmatory Test, Results of The Two Tests Were Interpreted Serially. A Cluster Was Said to Be Positive if at Least one Animal Reacts Positively by Both RBPT And CFT.Item Seroprevalence and Outbreak Investigation of Foot and Mouth Disease in Selected Sites of Tigray Region(Addis Ababa University, 2010-06-01) Berihun Afera; Yilkal AsfawThe present study was conducted in selected sites of Tigray Regional State from September 2009 to May 2010 with the objectives of determining the seroprevalence of foot and mouth disease, its associated risk factors and identification of serotypes existing in the Region. For seroprevalence and serotyping a total of 1138 cattle sera and 5 tissue samples were collected respectively and investigated using ELISA and PCR . Out of the total sera 446 (39.2%) were seropositives and SAT2 was detected from outbreak investigated from Maykadra using PCR. Seroprevalence in different age groups showed 40.4% (212/525), 38.7% (147/380) and 37.3% (87/373) in age groups 1-3, 3-6 and> 6 years with no statistical significance difference (P>0.05) among the groups. The seroprevalence in the different breeds was 40.6% (3231795) 32.2% (S71177), and 39.2% (661166) in local, cross and exotic breeds respectively with slightly higher prevalence in local breeds even though there is no statistical difference (P>0.05) among the breeds. The serosurveillance result between male and female were also recorded with values of 39.8% (2791701) and 38.2% (167/437), respectively, with no statistical difference between sexes (P>O.OS). Highest prevalence was recorded in Hintalowejerat peasant association 70.8% (85/120), the prevalence in the different peasant associations were 6S.8% (98/149), 4S.9% (68/148) and 38.2% (63/16S) in Gijet, Wukro and Shinkemajo, respectively. Similarly, the prevalence of the disease in Maymesanu, Agazi, Mekhoni and Dibla were 37.7% (29177), 21.9% (33/ISI), 21.6% (54 /250) and 21.5% (16/78), respectively. The variation was significant in the peasant associations (p<0.05). The occurrence of the disease was due to unregulated movement of animals from one region to another region and across boundaries and contact among different animals in different watering and grazing points. In addition, absence of vaccination program against the disease was reported by respondents. Vaccination, movement control and separation of different animals for reduction of the prevalence of the disease as a whole are suggested as actions recommended to mitigate FMD in Tigray Region.Item Seroprevalence of Contagious Caprine Pleuropneumonia in Borana and Guji Lowlands, Southern Ethiopia(2008-06) Tesfaye Bekele; Yilkal AsfawA multistage cross sectional serological study, questionnaire survey and participatory appraisal were conducted on contagious caprine pleuropneumonia (CCPP) from October, 2007 to April, 2008 in Borana and Guji lowlands, Southern Ethiopia, to determine the prevalence of the disease, to identify the risk factors for the occurrence of the disease and to assess the perception of the community on CCPP in particular and other goat diseases in general. A total of 951 serum samples (900 from goats and 51 from sheep) were collected and tested using Complement Fixation Test (CFT). Questionnaire surveys were conducted with 69 randomly selected households. Participatory disease appraisal was done with 12 informant groups in 12 different villages, the group size varying from 5-12 informants and with a total of 120 informants. Out of the 900 goat sera samples tested, 119 (13.2%) were seropositive for CCPP, giving an overall seroprevalence of 13.2 % (95%CI=11.0%-15.4%) in the study areas. A seroprevalence of 18.3% (95% CI=14.3%-22.7%), 11.7% (95% CI=8%-15.2%) and 9.7% (95% CI=6.3%-12.6%) were recorded in Liban, Teltale and Moyale Districts, respectively. The seroprevalence recorded among the districts was significantly different (p<0.05). The seroprevalence recorded in Liban district was significantly different from that of Moyale District (p<0.05). Moreover, out of 51 sheep samples tested, 3 (5.9%) were seropositive. Statistical analysis on the assumed risk factors showed that the seroprevalence observed in age groups, flock size groups and distance from veterinary service centre were found to be significantly different (p<0.05). Multivariate logistic regression analysis on the assumed risk factors showed that age, flock size and distance from veterinary service centre were the major risk factors for the occurrence of the disease in the area with Odds ratios of 2.18 (95% CI=1.64-2.91), 1.59 (95% CI=1.11-2.29) and 1.43 (95% CI=1.03-1.98), respectively. Contact at watering points, restocking, lack of veterinary service, and large flock size were identified to be the major factors for the spread and occurrence of the disease in the area. Participatory disease appraisal has indicated that the community has good knowledge about contagious caprine pleuropneumonia and other goat diseases, implying that the indigenous knowledge of the pastoral community could be used complementarily with the conventional disease investigation technique in the area. In conclusion, the serological findings, questionnaire survey and participatory appraisal have indicated that contagious caprine pleuropneumonia was XIV the top major goat health problem in the area which warrants appropriate measures to be in place towards the prevention and control of the disease in the study areas.Item Seroprevalence of Pest Des Petitis Ruminants and its Associations with Potential Risk Factors in Domesticated Small Ruminants, Cattle, Camel in Jijiga and Shinille Zone of Somali Region, Ethiopia(Addis Ababa University, 2009-06) Teffera Sime; Yilkal AsfawCross-sectional study was conducted in Jijiga and Shinille Zones of Somali Regional State from October 2008 to April 2009 to determine seroprevalence and associated risk factors. A multistage sampling was used in pastoral and agropastoralsystem. A total of (n=616) goats, (n=202) sheep, (n=110) cattle and (n=94) camel sera were collected for serological study. questionary survey was conducted in pastoral and agro-pastoral system. The seroprevalence of PPR in goats and sheep was 25.6% and 14.4% in the study area respectively. The seroprevalence was lower in camels and cattle, which was 8.5% and 6.63% respectively. Goats were found to be more susceptible than sheep, which was found to be statistically significant (p=O.OOO). However no significant difference was observed between cattle and camel (P=0.558). Seroprevalence of goats between Shinille Zone (pastoral) and Jijiga Zone (agro-pastoral) production system showed 44.09% and 18.9% in goats, 30.01% and 5.42 in sheep respectively. Sero prevalence increased from 21.7%% to 28.9%%% in goats and from 8.1 %to 20.4%in sheep from young to adults age respectively. There was significant difference between age groups in seroprevalence of both goats (p=0.04) and of sheep (0.013). In case of cattle (p=0.062) and camel (p=0.249) statistically no significance difference was observed between age groups in seroprevalence. Regarding sex, 26.4%, and 25.5% was found in goats (p=0.851), 15.6% and 14% in sheep's 8% and 5 %( p=O. 795) in cattle (p=0.488) and8.2% and 9.5% in camel (p=0.095) in male and female respectively. There was statistically no significant difference between sexes in all species. According to the respondent the number of goats affected by CCPP (Sunbub) and PPR (Kollere) was 32.8%, 21.4% and 25.7%, 14.3% in Shinille and Jijiga Zone respectively. However more goats are affected by GIT parasite in Jijiga (40%) than Shinille zone (21.4%). Regarding susceptibility by age 64.28% and 60.7% of the respondent replied that young goats and sheep were more susceptible than adult animals. However, no response (0%) was made indicating susceptibility of goats and sheep less than 6 months of age. Key words: goat, sheep, cattle, camel, , cELISA, Peste des petits ruminants, Seroprevalence, Risk factors, Jijiga Zone, Shinile Zone.Item Seroprevalence Study of Brucellosis in Cattle and Human in Bahirdar Milkshed(2005-06) Mussie Hailemelekot; Yilkal AsfawA cross-sectional study was conducted in South Gondar, West Gojjam and Awi zones of Amhara Regional State, between October 2004 and March 2005, to determine the sero-prevalence of brucellosis in cattle and humans as well as to identify the likely potential risk factors. Two stage cluster-sampling was employed, by which 11 towns are identified as primary units and 195 farms as secondary units in semi-intensive production system. Similarly, 29 Peasant Associations as primary units and 145 individual cattle owners as secondary units were selected for the extensive production system. In the government cattle breeding ranch all eligible cattle were sampled. Human risk groups were sampled using purposive sampling method. The study methods involved collection serum sample, data, questionnaire surveys and serological tests conducted in laboratories. Accordingly, 1944 cattle (341 clusters in the three production systems) were sampled. The sampling involved all cattle above 6 months of age with no history of previous vaccination against brucellosis. The number of cattle sampled in extensive, semi-intensive and ranch were 864, 754 and 326, respectively. The types of tests used to detect the presence of Brucella antibodies were Rose Bengal Plate Test (RBPT) as screening test, and Complement Fixation Test (CFT) as confirmatory test. Results of the two tests were interpreted serially. A cluster was said to be positive if at least one animal reacts positively by both RBPT and CFT. The overall individual and cluster level sero-prevalence of cattle in the extensive, semi-intensive and ranch were 4.63 % (n=90) and 14.96 % (n=51), respectively. The within cluster sero- prevalence varied between 0% and 100%, with an overall mean (±SD) of 24.27% (±17.68). For semi-intensive production system, the sero-prevalence varied between 0% and 100% the mean (+SD) sero- prevalence was 26.82 % (±22.52), and in the extensive production system the within cluster sero-prevalence varied between 0% and 50% and an average (+SD) sero- prevalence of 25.44% (±10.45). There was a highly significant difference in sero-prevalence to Brucella antibody among Awi, West Gojjam, South Gondar at both individual level (p=0.000) and cluster level (p=0.000). However, Awi and West Gojjam zones did not vary significantly at both individual and cluster X II levels. In the midland and highland Brucella sero-reactor varied significantly at both individual level (p=0.000) and cluster level (p=0.000), respectively. Apparently there was no significant difference among the ranch, extensive and semi-intensive production systems, at both individual and cluster levels (p=0.082) and (p=0.255), respectively. Sero-reactor female and male were found to vary significantly in the semi-intensive production (p=0.042) as opposed to extensive (p=0.115) and ranch (p=0.50). Generally, females were found more affected. Significant difference in sero- prevalence to Brucella antibody among age groups (0.5-1,>1- 3, >3 years) was observed in the semi-intensive production (p=0.001), yet in extensive production and ranch the variation was not significant. Virtually, the sero-porevalences of the three herd categories having < 5 cattle, 5- 10 cattle and those with > 10 cattle were found significantly different in semi-intensive production (p=0.000); however, herd size had not been crucially important in extensive production. Our current finding revealed no significant variation between the two breeds of cattle, Fogera (indigenous zebu) and cross bred (Fogera X Friesian). Abortion and retained fetal membrane were found to be significantly related to brucellosis in the semi-intensive production (p=0.021) and (p=0.001), respectively; however, the two clinical signs were not found significantly associated in the extensive production. None of the management and husbandry related factors from the questionnaires were found significantly associated with sero-positivity, though a few of them had some association. Of the total 238 human serum samples tested, 3.78% (n=9) sera were found positive; both sexes were almost equally affected. Although not statistical significant, middle and old age groups were more affected than younger ones. In conclusion, the present study revealed a wider distribution of sero-reactor cattle in the study area; similarly the zoonotic importance of the disease was established, hence warranting future detailed study in the area.Item Study on Mycobacterium Bovis Using Conventional and Molecular Methods in Cattle Slaughtered in Kombolcha Elfora Meat Processing Plant(2008-06) Desta Fekadu; Yilkal AsfawA cross-sectional study was conducted on 1138 heads of cattle at Kombolcha ELFORA meat processing plant, South-Wello Administrative Zone, Amarha Regional State from November 2007 to May 2008. The objectives of the study were to estimate the prevalence of bovine tuberculosis in cattle slaughtered at Kombolcha ELFORA meat processing plant, and to isolate and characterize the strains of mycobacteria from tuberculousis suspicious lesions. Detailed post mortem examination, bacteriological culturing, regions of difference-bases polymerase chain reaction and spoligotyping were used. The prevalence of bovine tuberculosis was 5.0 % (57/1138) in cattle slaughtered at Kombolcha ELFORA meat processing plant on the basis of detailed post-mortem examination. There was no significance difference in prevalence between male and female (P > 0.05), as well as among the age groups (P > 0.05). Mycobacteria were able to be isolated from 28 of the 57 cattle with gross lesion. A total of 49 isolates were recovered from the different tissues of these 28 cattle, and 20 isolates showed signal for M. tuberculosis complex species of which 19 were M. bovis while one isolate was M. tuberculosis. Further characterization of the strains of M. bovis using spoligotyping revealed the presence of five different cluster of spoligotyping pattern, which include Ethiopian M. bovis train 1, SB1176, SB0134, SB0133 and new strain. The binary number representation of the new strain is 1100000101010110111111111111111101111100000 where 1 indicates the presence of a spacer and 0 indicates a loss. The new spoligotyping was not reported previously from elsewhere to the M. bovis database (www.mbovis.org). The findings of this study indicated that tuberculous lesions were common in cattle slaughtered at Kombolcha ELFORA meat processing plant, and hence detailed post mortem meat inspection procedures are required to minimize the risk of its transmission to the public through meat consumption. In addition, appropriate cooking of meat is required before consumption.