Veterinary Epidemiology

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A Prevalence Study on Bovine Mastitis in Selected Areas of Ethiopia and Efficacy Test of Medicinal Plants on Commonly Isolated Pathogens of Bovine Mastitis
(Addis Ababa University, 2010-06) Mandefro Dargie; Yasmin Jibril
The study was conducted with an objective of determining prevalence of mastitis in local zebu and cross breed lactating cows and assessing efficacy of seven phytopreparatons on commonly isolated pathogens of bovine mastitis. The study was based on 369 lactating cows with in small-scale extensive and semi-intensive husbandry practices in two selected highland and midland areas of Amhara region and in a large-scale intensive farm in Algae ATVET College. During sampling, each quarter was inspected for clinical case of mastitis and quarter milk from each cow was tested with CMT for sub-clinical mastitis. Plants were collected from their natural habitat, prepared, extracted and impregnated for efficacy test on (n= 12) isolates of Staphylococcus aureus and Streptococcus agalactia. With combined clinical inspection and CMT test, an overall prevalence of mastitis was 50.7% (16.0% clinical and 34.7% sub clinical) are cow base and 39.8% (6.3% clinical and 33.5% sub-clinical) at quarter level. A binary logistic regression analysis showed statistical associations of intensive farms (OR= 10.727, p= 0.000) with the disease than extensive husbandry practices. Cows at third and above lactation were statistically associated (OR= 5.418, P = 0.000) with mastitis than cows at first lactation. From seven plants tested for efficacy Bereza, Commicarpus pediculosus, Cyphostemum adenocaule and Xanthium stramarium showed visible zone of inhibitions. There was a significant difference' observed within mean zone of inhibition of plant types. Mean zone of inhibition from 20% Commicarpus pediculosus (29.00mm) was found statistically higher than (P
African Horse Sickness: Study on Seroprevalence and Dentification of Risk Factors in Equidae at Selected Sites in Ethiopia
(2006-06) Kassa Demissie ; Yilkal Asfaw
A 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.
Assessment and Mapping of Contagions of Contagious Bovine Pleuropneu Monia in Kenya and Present
(AAU, 1999-12) Salome. W Wanyoike; M. P. 0 Baumann
A rctfospcctive study was carried out in Kenya with lhc objective to summarise and map CBrp outbreaks. tu relate th em tll caule movement patterns. to assess vaccination coverage. and to evaluate factors affecting the reporting of CBPr.to passive data were collected for 1989 to 1998 from district reports. slaughterhouse reports and laboratory reports. Active data were collected by questionnaires in 8 districts Tana river where CBPP is believed to be endemic. Data werw collected by questionaiuers in 8 distrcts tana river .where CBPP in belived to be Mwing lMuenig Makuen kiajiado. and Thika which are believed to be Newly infected. and Kiambu and Nairobi districts \'hieh arc regarded as CUPP free. 166 fanner. 14 veterinarian. 12 slaughterhouse and 18 para\ctcrinary persollnel questionnaires were administered primarily to tlctcnnine the factors affecting disease reponmg. and to describe the production systems and also additional infunllation 011 CBP P outbreaks,Vaeeinations and cattle movcment. i\lap Info Profcssional and Arc View 3.0a \\cre used to map CBPP vaccinations and its relation to cattle movcmcnt pauems. Microsoli Excel 97 and tatSgraphics Lpus 2.1 were used to store and analyse respectively the data obtained
Bovine Tuberculosis in Central Ethiopia: Epidemiology, BCG Efficacy in Reducing Transmission, and Performance of Defined Antigen Cocktails for Differentiating Infected from Vaccinated Crossbred Cattle
(Addis Abeba University, 2025) Abebe Fromsa; Prof. Balako Gumi
: Bovine tuberculosis (bTB) is a threat to animal health, the livestock economy,food security, and human safety. Although animal level prevalence ranges from 25% to 39% and herd prevalence exceeds 50% in intensive dairy farms in central Ethiopia, control measures are lacking. The conventional test-and-slaughter strategy is resource-intensive and unaffordable for low- and middle-income countries (LMICs) such as Ethiopia. This necessitates a cost-effective alternative control strategy. Bacillus Calmette-Guérin (BCG) vaccination may constitute a cost-effective approach to control bTB in LMICs and regions with wildlife reservoirs. A meta-analysis of previous BCG vaccine evaluation studies demonstrated limited overall direct efficacy of 25% and additional partial protection by reducing the frequency and severity of disease pathology. Whether this partial protective effect translates into indirect protection through a reduction in the infectiousness of vaccinated animals has not been evaluated. Besides, since the interference of the BCG vaccine with the tuberculin skin testing is a major hindrance to the deployment of BCG vaccination for cattle, there is also a need to adopt a diagnostic test that differentiates infected from vaccinate animals (DIVA). On top of these, a slaughterhouse survey was conducted to identify hotspots of bTB in central Ethiopia to prioritize targeted control measures. Objectives: The objectives of this study include to quantify the direct and indirect efficacies of BCG vaccination in crossbred cattle, evaluate the diagnostic performance of defined peptide antigen cocktails (ESAT-6, CFP10, and Rv3615c) in differentiating infected from vaccinated animals (DIVA), assess the practical implications of routine vaccination on the spread of bTB in the emerging dairy sector, and estimate the prevalence and identify the causative agents of bTB in cattle in central Ethiopia. Methodology: A natural transmission experiment was conducted using a crossover design in two phases, each lasting for one year to evaluate both the direct and indirect effects of BCG vaccination in reducing the transmission of bTB. Sixty-seven unvaccinated control and 67 vaccinated calves were exposed to an equal number of respective seeders eight weeks postvaccination and maintained in contact for twelve months during each phase. Sixty-five unvaccinated control and 62 vaccinated calves underwent postmortem tests. Skin and IGRA tests were conducted using tuberculin and DIVA antigen cocktails every four and two months, respectively. For efficacy evaluation, calves that ever tested positive for DIVA antigens in the IGRA test were considered infected and potentially infectious. Then a mechanistic transmission model calibrated using within-herd basic reproduction number (Ro) and empirical cattle movement data was used to explore the long-term effect of routine BCG vaccination in controlling bTB in the Ethiopian dairy sector. The performance of DIVA antigen cocktails was compared to tuberculin in both IGRA and skin test formats. A slaughterhouse survey was conducted in Central Ethiopia to assess the prevalence, risk factors, and causative agents of bTB. The causative agents were identified using multiplex quantitative PCR (m-qPCR) in all culture-positive samples. Result: The study found a significantly lower total visible lesion score in vaccinated animals compared to unvaccinated controls and a reduction in bTB transmission of 74% (95% CI: 46– 89%) among vaccinated animals compared to unvaccinated controls. The direct efficacy was 58% (95% CI: 34%–73%). The combined direct and indirect effects resulted in a total vaccine efficacy of 89% (95% CI, 74–96%). The estimated Ro, representing the average number of secondary cases per infectious individual was 3.1 (95% CI: 2–4) in unvaccinated group while it was 0.3 (95% CI: 0.1–0.7) in the vaccinated group. A mechanistic transmission model suggests that routine neonatal calf vaccination has the potential to reduce the average population Ro to below 1 within 10 years, presenting significant opportunities for the control and elimination of bTB in cattle. Eight weeks after vaccination, but before exposure to infected seeder animals, the specificities of IGRA and skin test-based defined antigen cocktails were 98.5% and 94.0%, respectively. However, at the end of the experiment, the sensitivities of these tests were 46% and 47%, respectively, which were similar with 45% sensitivity of the comparative tuberculin test (CCT). A slaughterhouse survey revealed the ongoing challenge of bTB in Central Ethiopia, with a prevalence of 2.3% bTB-related lesions and an eleven-fold greater risk in crossbred cattle than in local zebu cattle. All mycobacterial species isolated from experimental and slaughterhouse cattle were identified as M. bovis, except for two cases from the slaughterhouse. One of these cases exhibited co-infection with M. bovis and M. tuberculosis, while the other was co-infected with M. bovis and M. caprae. However, no positive M. orygis was detected in any of culture-positive samples. Conclusions: The study revealed previously unrecognized superior indirect effects of BCG on bTB transmission compared to its direct protective effect against infection. Scenario analyses using mechanistic models indicate that BCG vaccination may enable effective control of bTB and contribute to elimination efforts. DIVA antigens demonstrated high specificity in BCGvaccinated cattle, highlighting their importance for potential integration into BCG vaccination programs for bTB control. These findings hold significant implications for resource-limited settings where the test-and-slaughter strategy is not feasible, while vaccination combined with DIVA testing remains a beneficial and effective approach. The higher risk of bTB in crossbred cattle underscores the necessity for targeted interventions, particularly in crossbred cattle predominantly raised in intensive dairy production systems.
Camel Management and Status of Camel Brucellosis in Jijiga Zone South East Low land Areas Somali National Regional State Easern Ethiopia
(Addis Ababa University Faculty Of Veterinary Medicine, 2006-06) Berhanu Tilahun; Merga Bekana
A cross-sec tio nal Clwlcmio \ogicai study was carried out from October 2005 to March 2006 10 delL'11111l1C tht: S I.;roprc\a1cncc 0 r c ame\ b n1cc llosis in s Ollth cas! 10\\ I and a rcas 1 n JiJ iga lone, Soma li 1\a1l011 '-11 Regional State (SNRS). to characterize the management system. determine the scroprcva\cnce of camel brucellosIs and identify the risk faclOrs that contribute to the OCCU1Tcncc of bmccllosis. A simple ra ndom sampling method was used to seleci 822 camel and 185 he rds (households) 59~ camels 0.05). The he rd level seroprc\alence \\as 10.3°u (95 0 oCI= 6.7-15.7). Although the herd le\'eI seroprc\'alcnce was higher in JiJlga (12°/0 ) than III Bahik (5.811 ,,). the liJffercnc( \\as not stallstlcally sign ificant The herd !c\c[ seropre\akncc \\as slg1l1licantl~ lllCfeasJIlg \\ IIh the Illcrement of thc herd size (p
Camel Management and Status of Camel Brucellosis in Jijiga Zone Southeast Lowland Areas, Somali National Regional State, Eastern Ethiopia
(2006-06) Berhanu Tilahun; Merga Bekana
A cross-sectional epidemiological study was carried out from October 2005 to March 2006 to determine the seroprevalence of camel brucellosis in south east low land areas in Jijiga zone, Somali National Regional State (SNRS), to characterize the management system, determine the seroprevalence of camel brucellosis and identify the risk factors that contribute to the occurrence of brucellosis. A simple random sampling method was used to select 822 camel and 185 herds (households). 594 camels and 133 herds were selected from Jijiga area while 228 camels and 52 herds were selected from Babile area. Serum samples were collected from all camels (822) 2 years old or above. The blood samples were screened by RBPT and all RBPT positive reactors were further tested by the CFT for confirmation. Additionally, a structured questionnaire format was prepared and administered to hundred of the 185 selected households to collect information about animal attributes and farm attributes. The results showed that significant proportions of the households kept camel together with cattle and shoats (40%) and only with cattle (32%). The camel herd was dominated by pregnant animals (21.8%), lactating animals (21.1%) and mature non-lactating animals (19.3%). The most important diseases affecting camels in the area as mentioned by the households were trypanosomosis (93%), anthrax (80%), pneumonia (70%), bent neck (59%), abscess (59%), endoparasites (54%) and ectoparasites (51%). Camel management practices like herding and watering, milking and delivery and mating assistance were mainly the responsibilities of adult and young males. In this study, the overall seroprevalence of brucella antibodies in camels was 2.43%( 95% CI=1.6-3.8). Among the potential risk factors considered (sex, age, herd size and parity), none of them had significant effect on individual animal seroprevalence (p>0.05). The herd level seroprevalence was 10.3% (95%CI= 6.7-15.7). Although the herd level seroprevalence was higher in Jijiga (12%) than in Babile (5.8%), the difference was not statistically significant. The herd level seroprevalence was significantly increasing with the increment of the herd size (p<0.01). It can concluded thus camel brucellosis had low prevalence in the areas and herd size was the important risk factor for the occurrence of the disease at herd level.
Cart and Harness Characteristics of Draught Equids in the Oromia Region; The Contribution of Local Cart and Harness Design to the Welfare of Working Equids
(Addis Abeba University, 2022) Abel Legesse; Teshale Sori
The study was conducted from November 2021 to May 2022 in three selected towns of Oromia region Bishoftu, Selale, and Shashemene to assess cart and harness characteristics and its contribution of local cart and harness design to the welfare of working equids . A total of 369 equines were examined during the study period, with 244 (66.12 %) horses, 122 (33.06 %) donkeys, and 3 (0.81 %) mules being examined for general attitude, gait, response to spinal contact, presence of shoes, lesions on various parts of the body, hoof and limb conditions, and body condition status. When the proportion of work types was compared to the study region, Bishoftu, Selale, and Shashemene differed. In Bishoftu, 72.88 % use taxis, 19.43 % use transit, and 7.68 % utilize water transportation. A taxi driver, like Bishoftu, was the most frequent type of work in Selale. It was 74.32 %, with goods transport accounting for 21.66 % and water transport accounting for 3.53 %. Cart taxi service is virtually non-existent in the Shashemene area. The bulk of carts were used to transport commodities and water, accounting for 82.84 % and 17.15 %, respectively, of all carts. The study found that 13.11 % of the 122 donkeys were "Very thin," 84.42 % were "Thin," and 2.45 % had "Ideal" physique scores. The condition "Thin" accounted for 53.68 % of the total horse population, followed by "Ideal" condition, which accounted for 23.36 % of the total horse population. The third and last segment was occupied by a very thin body score condition, which accounts for around 22.95 % of the total. From the total sample 75.60% of working equids were found with wound on different body parts in Bishoftu, 67.47% in Selale and 84.55% in Shashemene area because of improper fitting of harness materials. Girth wounds account for the majority of these three major wound results, accounting for 43.90 % of all wounds across the research region. Chest wound 23.30 % and saddle wound 22.49 % took second and third place, respectively. In the current study, we discovered that equines play a significant role as useful animals in both rural and urban communities. Cart and harness features such as unfitted, thinner saddles, use of unbreathable paddings, lameness, wound, overworking, overloading, injuries, and general abuse were common. Further research and appropriate interventions should be explored on the welfare restrictions impeding the optimal use of equines in this critical area.
Cattle Foot and Mouth Disease Prevalence and Its Deteminants in Selected Districts of Tigray Region, Ethiopia
(2015-06) Azeb G/tensay; Reta Duguma
A cross-sectional serological study and questionnaire survey were conducted in two districts of Tigray Regional State with the objectives of determine the seroprevalence of FMD and assess potential risk factors associated with FMD occurrence in selected districts of Tigray region. The study was conducted from November 2014 to April 2015. A total of 400 cattle sera sample were collected and tested for antibodies against FMDV using 3ABC ELISA. Out of the total sera 39 (9.8%) were sero-positive and within districts Sheraro 30 (15%) and Seasie Tseada Emba 9(4.5%). Significantly higher prevalence was observed with different Peasant Association in that Adiaser 19.1% whereas lower prevalence was recorded in Saze 2.9%. There was a strong significance difference (p=0.000) in FMD prevalence between lowland 15% and highland 4.5%. Seroprevalence in different age groups showed significant variation 4.5% (8/177), 14.1% (28/198) and 12% (3/25) in age groups ≤ 4, 4-10 and >10 years (P<0.05). The seroprevalence in the different breeds was significantly higher (p= 0.002) in Begait 15% (30/200), compared to local and cross breeds 4.3% (6/139), 4.9% (3/61) respectively. The seroprevalence result between female and male were also recorded with values of 11.9% and 7.1% respectively, with no statistical difference between sexes (p= 0.108). In large herd size there was higher prevalence of FMD 22.7% than small herd size 6.2% with (p= 0.03). In addition, 90% of the respondents reported that there was no vaccination in the study area especially in Sheraro district. All respondents reported their cattle were used common watering point and grazing land. Farmers appears to have good knowledge of the clinical manifestation, seasonality and economic impact of FMD but not aware of the interspecies transmission of the disease between shoats (small ruminants), wildlife and due to contacts at watering and grazing points of risk factors. Further studies are also recommended to characterize the circulating FMDV serotypes in the areas and investigation in wildlife and small ruminant is needed to determine their roles in FMD virus maintenance and transmission.
Conventional and Molecular Epidemiology of New Castle Disease Virus in Wild and Domestic Birds in Selected Rift Valley Areas, Ethiopia
(2017-06) Gelana Haile; Fufa Abunna
New castle disease is a highly contagious and devastating viral disease of wild and domestic birds. The cross-sectional study was conducted from February 2016 up to March 2017 on domestic and wild birds in selected rift valley areas of Ethiopia to study epidemiology of Newcastle disease in wild and domestic birds. A total 300 domestic backyard chicken were selected, 150 of them blood sample for serology and 150 pools of five trachea and cloaca swab samples and also from wild birds 60 pool of five faecal droplets and ten swabs from pigeon were sampled. The samples were tested by Haemagglutination Inhibition and molecular characterization was done by real time reverse transcriptase polymerase chain reaction targeting a conserved region of the Fusion gene to specifically amplify virulent Newcastle disease virus strains. Laboratory results were analyzed using descriptive statistics, chi-square test, fisher’s exact test and logistic regression. The overall sero-prevalence of Newcastle disease in domestic birds was 12.7% (19/150) with statistical no significant difference among the study districts 20% (10/50), 12% (6/50), 6% (3/50) in Bishoftu, Hawassa and Batu, respectively. The samples collected from trachea and cloaca swab tested by real time reverse transcriptase polymerase chain reaction 16.7% (7/30) of New castle disease virus was tested that 20%, 15%, 15% from Bishoftu, Hawassa and Batu, respectively, with statistical no significance differences among the study districts. In the wild birds all faecal droplet samples tested by real time reverse-transcriptase polymerase chain reaction were negative where as 50% (5/10) swab samples from Pigeon were positive to Avian Paramyxovirus-1. The questionnaire survey response indicated that interaction of domestic poultry within the market and with wild birds and presence of water bodies has been recognized as a possible source of New castle disease. The current study provides important information on serological, associated risk factors and molecular characterization of New castle disease virus in the study areas, and hence it should be applied prevention and control methods and detail study will be conducted.
Cross Sectional and Longitudinal Study of Bovine Mastitis in Urban and Peri-Urban Dairy Systems in the Addis Ababa Region, Ethiopia
(Addis Ababa University Faculty Of Veterinary Medicine, 1999-12) Nesru Hussein; Bayleyegn Molla
Cross-sectional and Longitudinal Prospective Study of Bovine Clinical and Subclinical Mastitis in Peri Urban and Urban Dairy Production Systems in the Addis Ababa Region, Ethiopia
(AAU, 1998-01) Alee Simukai Bishi ; Zessin
This study was conducted to establish the prevalence and incidence of clinical and subclinical Mastitis in peri-urban and urban dmry production systems in and around Addis Ababa and Debre Zeit, Ethiopia. A questionnaire survey was also conducted to gain an insight in to the farming systems in operation, and to study some management and social factors that may have an influence on the occurrence of mastitis. The main aim of this study was to demonstrate the effect of intensification (farm size in particular) on the Occurrence o f mastitis
Cross-Sectional Study of Bovine Mastitis in Urban and Peri-Urban Dairy Farms of HARAR Town
(Addis Ababa University, 2010-06) Ketema Bogale; Yaslllin libril
A cross sectional study of bovine mastitis was carried out from September 2009 to May 2010 in urban and peri-urban dairy farms of Harar town to determine the prevalence of mastitis on cow and quarter level , to isolate and identify etiological agents for mastitis and to assess the effect of associated risk factors. From 36 dairy farms 34 1 lactating cows were investigated. Of these 143 cows (4 1.9%) were Positive by California Mastitis Test (CMT) and 138 cows (40.5%) were culture positive for mastitis. Among culture positive cows 23 (6.8%) and 11 5 (3 3.7%) were infected clinically and sub clinically Respectively. Out of 1364 quarters 51 were blind, 22X ( 17.4%) were positive by CMT and 214 ( 16. by culture. Frequency of clinical and sub clinical mastitis on quarters were 41 (3 .1%) and 173 ( 13.2%), respectively. Logistic regression analysis showed that prevalence of mastitis was significantly higher in third parity than the lira (p<0.05) in early lactate on sage than in late (p<0.05). Hygiene, ventilation and drainage were also found to be significantly associated with the occurrence of mastitis (p<0.05). However, herd (farm) size and quarters position were not significantly associated with mastitis (p>0.05). From the isolated mastitis causing pathogens Staphylococcus species were the most prevalent (42 .9%) Followed by Streptococcus species (28 .3Enlerobaeter "Coli forms" (20.0%) and other gram positive bacteria (8.8%). Through the questions ire survey it was confirmed that poor farm management, unhygienic milking practices, lack of knowledge about the role of risk factors on mastitis occurrence and hidden (subclinical) mastitis are reasons for the increased prevalence of mastitis (40 .5%) in the study area. Antimicrobial susceptibility test situ wed that most of the isolates in this study were found to be highly sensitive to cloxacillin, gentamycin and amoxicillin, and moderately sensitive to ampicillin and ox tetracycline However, Staphylococcus s and Streptococcus species were highly resistant to streptomycin and penicillin. Key words: milking cow, mastitis, prevalence, quest unaired, risk factor, udder, quarter, CMT, culture, sensitivity test, dairy farm s. Harare
Cross-Sectional Study of Mastitis In Camels (Camelus Dromedarius) in Selected Sites of Ethiopia
(AAU, 2001-11) Atif EI amin Abder Gadir; Goetz Hildebran
== One thousand and twelve udder quarter from 253 traduionally Managed lactating camels( Camelus dromediarus were invesugated according to multi-saage. sampling In the study Sits. Out of the 1012 udder quarters. 35( 3 .46%) quarters were blind and 21(2.08) (quarter milk samples were lost dunng handhng. The remamIng 956 quarter milk samples 1.f66. 305. 185 from Negele (Bprene Rorena Region DIRE and Gewane (Afar Region)Respectively )Were Tespectively) Were Tested For California Mastiis Test (CMT) SOMATIC CEIL Counts (SCC). And bacteriological analysis
Current Epidemiological Situation of Bovine Trypanosomosis in Limu Shay Tsetse Controlled Area of Upper Didessa Valley
(AAU, 2004-06) Feyesa Regassa; Abebe Getachew
Trypanosomosis is one of the most devastating diseases which afflict both people and animals in Africa. The Ethiopian government is placing a great emphasis on tsetse control activities. The control program must fit into the rural development policy of the country and monitoring and impact assessment of the control programs is equally important. The main objective of the study was to assess the prevalence of bovine trypanosomosis with regards to changes in tsetse density and to assess the socio-economic impact of tsetse control in Limu Shay tsetse controlled area of the upper Didessa valley. The impact of tsetse control in Limu Shay was assessed by comparison with the tsetse infested (Didessa) area. The study was carried out from October 2003 to March 2004 and comprised of cross sectional study on the disease and its ector tsetse fly questionnaire and collection of the recorded data for socioeconomic impact assessment. The pre alence study was carried out on 810 randomly selected cattle using the dark ground! phase contrast buffy coat technique (BCT). A total of 180 monoconical traps were deployed along the identified localities and suitable tsetse habitats (1300-1525 meters abo e sea level) to determine the mean catch and tsetse apparent densities. A total of 180 family heads were interviewed by using standard questionnaire particularly with questions co ering issues on Ii estock and crop production and together with the socio economic data from secondary sources were used to assess the socio-economic impact of tsetse control. Survey results in the tsetse controlled area showed 7.9% pre alence of trypanosome infection in cattle with a erage packed red cell volume (FCV) of 25%. In the tsetse infested area the pre alence and a erage PCV were 27.16% and 22.85% respecti ely. Similarly comparison of the tsetse infested area with the tsetse infested area showed 71 % reduction in trypanosome pre alence and 9.51 % increase in PCV values. The observed differences were statistically significQ.nt for pre alence (95% CI= 0.1490- 0.202' P< 0.001 and PCV (%) (95% CI= 23.623- 24.2387' P < 0.001). Tsetse fly mean catch between the tsetse controlled (mean=4.03) and the tsetse infested (mean=10.68 areas differed significantly (P< 0.05) with 62.4% reduction in the tsetse apparent density in the controlled area. 0 G. m. submorsitans was found in the tsetse controlled area but the apparent density 1.34 fly per trap per day in the controlled area 2.05 fly per trap per day in the infested area was reduced by 35% for G. tachinoides. The questionnaire survey result indicated that the cal ing rate was increased by 35.3%. The a erage age at first calving (42 months the a erage cal ing interval 20.04 months) and abortion rate (16.1 %) were also reduced by XIII 1l.5% 5.5 month 13.6% 3 months and 39% respecti ely in the controlled area a compared to the tsetse infested area. Mortality rate in the herds of controlled 7.9% area ho\-, ed 2% reduction a compared to the infested 29.1 % area. The differences ob erved benveen the tv 0 area were tatistically significant. Likewi e analysis of the data re ealed an increa e by 0% in average daily milk yield per co 1.67liters an increa e by 120% in a erage lactation yield 350 kg and decrease in the a erage use of trypanocidal drugs treatments of per animal per ear from 7.16 treatment in the infested area to 0.19 in the tsetse ontrolled area. Con, er el there wa a reduction by 40% and 90% for the producti e offtake rate ale and slaughter rate and purchase rate respecti ely in the controlled area a compared to the infe ted area. B comparison with the infested area oxen in the controlled area \.vere 0% and 31 % more efficient in the a erage work hour per day and in the a erage area culti" ated per 0 re pecti el . Anal is of the econdary source data howed that the number of cattle and draught oxen has increased b 323% and b 260% re pecti el 0 er 15 ear ben, een 19 and 2003. The increase in animal traction has in tum brought about change in culti ation practice with ubsequent increase in a erage area ploughed under animal traction b almo t 00% increa e and an a erage area cultivated per hou ehold b 00%. The a erage cultivated land per hou e hold increased b 1 5% a compared to the infe ted area. Be ide the population growth in the controlled area between 19 and 2003 " 'a found to be rapid at .2% annual growth rate. Based on the re ults of the pre ent tud it \-vas concluded that a reduction in trypano orne prevalence in cattle as ociated "',lith reduction In et e densitie and the di appearan e of G. m. submor itan a a re ult of t etse control improyed the ocio-economic activitie of the people in the tudy area.
A Description of the Primary Animal Health Prograivimes in Selected Areas of Southern Sudan and Ethiopia and a first Assessment of Programme Impacts
(AAU, 2001-12) Nimaya Kenyi; Mekonnen Hailemariam
In selected areas of southern Sudan (juba, Tcrekeka. Kapoeta) and Ethiopia (Afar. Zone 3 and 5; North Wollo) a study Wa!) conducted with the objectives to describe primary ammal heJ..lth care activities and approaches. to determine the level of community participation in anima] health services delivery. to assess the efficiency of primary animal health care workers and, thus. to provide a first assessment of the impact of PAHC activities on livestock disease control and livestock production Jote the study areas In u!:.lng partiCipatory appraisal (PA ) methods as well as structured questionnaires active data were collected through 90 and 30 livestock owner group imerviews. as well as through 53 and 9 CAH\V and 15 and 22 government animal health worker questionnaires during January to May 2001 in southern Sudnn and during July and August 2001 in Ethiopia. respectively PA data collected on iniciuded disease changes. milk uses and ocher benerits obtamed from healthy anlmals. community pamcipation in PAHC implementation and preferences In animal health sen Ices delivery Triangulation was used for the PA data collected in the fidd: for il!Hll~SIS of quantionaires PA data so factor changes were dtterrmned Structured questionnaire data were collected on demographics. activties and work Constnunts of CAHW and government vetenanry workers Addiuonally. government vetennary~ statt was(., asked on the lives.tock disease situation as well as on their aisessment of communir animal health care delivery in the respecuve .study areas. Acuvlty rauos were calculated to quantify and :ompare CAHW trealtmeni and vccination activitIes
Detection And Determination of Tetracycline Residue Levels in Beefg at Addis Ababa, D/Z, & Nazareth Slaughtered Houses
(2007-06) Addisalem Hunde; Bayleyegn Molla
A cross-sectional study was conducted from October 2006 to May 2007 to investigate the proportion of tetracycline residue levels in beef at Addis Ababa, Debre Zeit and Nazareth slaughterhouses. A total of 384 muscle and kidney samples were randomly collected from slaughtered cattle in the respective slaughterhouses. The samples were qualitatively screened for tetracycline residues by thin layer chromatography using a suitable silica gel (Merck silica gel 60 plates).The positive samples were then further analyzed by using high performance liquid chromatography (HPLC) Shimadzu Model Class-VP series with an electron diode array detector. The result of this study indicated that oxytetracycline residues previously detected in thin layer chromatography were detected in all samples by HPLC. A given sample was regarded as positive for tetracycline if its retention time and peak corresponded to that of the standard. Out of the 384 samples that were analyzed for tetracycline residues 274 (71.35%) had detectable oxytetracycline residues. Tetracycline and doxycycline were not detected. At Addis Ababa slaughterhouse, 120 (93.75%) of kidney and beef samples were positive for oxytetracycline. In Debre Zeit 48 (37.5%) of kidney and beef samples were also positive for oxytetracycline while from Nazareth slaughterhouse 106 (82.81%) of kidney and beef were positive for oxytetracycline. The mean (p>0.05) residue levels of oxytetracycline for the three slaughterhouses studied in muscle were as follows: Addis Ababa 108.34μg/kg, Nazareth 64.85μg/kg and 15.916μg/kg at Debre Zeit while in kidney samples were (p<0.05): 99.02 μg/kg in Addis Ababa, 109.35μg/kg in Nazareth and 112.53μg/kg in Debre Zeit slaughterhouses. The oxytetracycline positive samples, which showed residues of oxytetracycline above maximum residue limits (100μg/kg) in muscle samples, were 58 (48.33%) at Addis Ababa slaughterhouse and 51 (48.11%) at Nazareth slaughterhouse and 1 (0.9%) in the kidney samples of Nazareth slaughterhouse. At Debre Zeit slaughterhouse no samples were above the maximum residue limit. The results obtained confirmed that oxytetracycline was heavily and indiscriminately used in the fattening farms, small scale fattening farms, pastoralists and other animal owners. The results also suggest that the recommended withdrawal time was not strictly applied. Results of the present study could serve as a preliminary base line information for veterinary authorities, drug administration and quality control authority, other concerned organizations and professionals to take measures on control x and prevention of drug residues; as well as the consumer to be aware of the possible drug residue risks through consumption of unsafe animal products.
Detection of Rift Valley Fever virus from mosquito vectors and Mosquito distribution model Based Rift Valley Fever Risk Mapping in Ethiopia
(2019-06) Megarsa Bedasa; Haileleul Negussie
Mosquito-borne arboviral diseases are a big health challenge worldwide. Rift Valley Fever virus (RVFV) is one of the most important mosquito-borne emerging diseases that threaten human and animal health particularly in Africa. So far, the status of RVFV circulating in mosquito vectors is unknown in Ethiopia. Thus, this study was conducted with the aims of investigating RVFV vector mosquitoes, viral detection, and RVF risk mapping based on RVF mosquito vector distribution model in Ethiopia. Entomological survey was conducted between December, 2018 and April, 2019 in selected areas of mid-Rift Valley, Borena and Segen Valley, Ethiopia and the result showed diversified species of primary vectors (Aedes spp.) and secondary vectors (Culex, Anopheles, and Mansonia) were collected and identified. A total of 2,322 adult mosquitoes were collected and four genera: Aedes (n = 404; 17.40%), Culex (n = 466; 20.06%), Mansonia (n = 210; 9.04%), and Anopheles (n = 493; 21.23%) were identified while the remaining (746; 32.12 %) mosquitoes were unidentified. Aedes ochraceus (126; 8.0%), Cx. quinquefasciatus (141; 9.01%), the M. uniformis (210; 13.32%) and An. gambiae (64; 4.06%) were predominant species from the four genera. Among identified mosquitoes 45.55% and 22.78% were collected near lake shore and near pond, respectively, while the remaining were collected from others habitats. A total of 38 mosquito pools, containing 20-25 mosquitoes per pool, were tested by reverse transcriptase-PCR using the virus
Deteremination of Optimal Time of Vaccination Against Infectious Bursal Disease (Gumboro) And Molecular Diagnosis of Clinical Cases in Central Ethiopia
(2017-06) Samson Terefe; Teshale Sori
In spite of the intensive and varied vaccination procedures to control Infectious Bursa Disease (IBD), the emergence of a very virulent (vv) IBD pathotype in Ethiopia and post vaccination outbreak have led to high economic losses in the poultry industry. The objectives of this study was to determine optimal time of vaccination against IBD and molecular diagnosis of clinical cases in commercial poultry farms in central Ethiopia. The study was conducted from November 2016 to April 2017 on exotic breed chickens kept under semi-intensive and intensive poultry farms selected randomly by simple random sampling technique in Addis Ababa, Bishoftu, and Adama areas. It was a type of prospective longitudinal study where chickens were followed for a defined period of time until they reached 6 weeks of age for clinical cases. A total of 11 samples from 11 farms were collected from clinical cases of infectious bursal diease in chickens (5 samples from Bishoftu, 3 samples from Adama and 3 samples from Addis Ababa) were analyzed with RT-PCR. Of these 8 samples (72.73%; CI: 39.03 – 93.98) were positive for infectious bursal disease virus RNA. The RNA of IBDV was detected in 4 of 5 (80%) of samples from Bishoftu and 2 of 3 (66.67%) of samples from each of Adama and Addis Ababa. For vaccine experimental study, One hundred eighty, day-old Lohman brown chicks were reared and used for this purpose. The chicks were divided into three groups A, B, C. Groups A were vaccinated via drinking water route at 7th day whereas B were vaccinated at 14th day of age. Group C was acted as control. Blood samples were collected from wing vein of individual chicken at day 1, 7, 14, 21, 28, 40 and serum was harvested. Indirect Enzyme Linked Immunosorbent Assay (IELISA) was employed to measure antibody titration. The proportion of chicks in the unvaccinated group with S/P ratio greater than the protective level continuously fall from 0.90 on day 1 to 0.0 on day 14. At day 21 of age after hatching, the time IBD commonly occurred, 55% of the chicks in group A had protective antibody level with average antibody titre of 1064.61± 748.1621; whereas only 5% of the chicks in group B had protective antibody level with average antibody titre of 123.2321 ± 212.0105. It was concluded that in chickens with low MDA, the 1st vaccination should be given at 7th day and repeat after one week. The effect of vaccination programs on the immune response to IBD vaccine in the farms should be further investigated.
Diagnostic Performance of PCR and Microscopy and Molecular Surveillance of Chloroquine Resistance-Markers in Plasmodium Falciparum Clinical Isolates in Hawassa Sidama Ethiopia
(Addis Abeba University, 2026) Dibora Hailu; Samson Leta
Malaria is still a major public health problem in Ethiopia, particularly in areas with seasonal transmission, such as Hawassa, southern Ethiopia. Accurate diagnosis and continuous monitoring of antimalarial drug resistance are essential for effective control and elimination efforts. This study aimed to evaluate the diagnostic performance of PCR and microscopy and conduct molecular surveillance of CQ resistance markers in Plasmodium falciparum clinical isolates. A cross-sectional study was performed from September 2025 to May 2026 in selected health centers found in Hawassa, southern Ethiopia. A total of 1428 dried blood samples were collected from malaria-suspected individuals. Nested PCR targeting the 18S rRNA gene was used for species confirmation, while genotyping was conducted by restriction fragment length polymorphism (RFLP) to detect mutations in the pfcrt (K76T) and pfmdr1 (N86Y) genes. Statistical analysis was performed using R software version 4.3.2. Logistic regression was used to assess the association between infection status and participants' characteristics, and Cohen‟s kappa was used to assess agreement between microscopy and PCR. Out of 1428 samples, 546 (38.2%) were PCR positive for Plasmodium species, of which 214 were confirmed as P. falciparum. Sex was significantly associated with PCR positivity, with male participants exhibiting higher odds of infection compared to females (OR = 1.33, 95% CI: 1.04–1.69, p = 0.021). Age (as a continuous variable) showed no statistically significant association with malaria infection overall or by species (Pf and Pv), as the odds ratios were close to unity and the confidence intervals included 1 (Overall PCR: OR = 0.99, 95% CI: 0.98–1.00, P = 0.40; Pf: OR = 0.99, 95% CI: 0.98–1.00, P = 0.211; Pv: OR = 0.99, 95% CI: 0.97–1.00, P = 0.30). But age was significantly associated with microscopy positivity, (OR = 0.98, 95% CI: 0.97–0.99, p < 0.001). In conclusion, PCR showed superior diagnostic performance compared to microscopy, particularly for malaria species identification. Microscopy demonstrated moderate agreement for P. falciparum (κ = 0.426) and fair agreement for P. vivax (κ = 0.289), while overall agreement was substantial (κ = 0.611; accuracy = 82.56%). Molecular analysis revealed fixation of the pfcrt K76T mutation (100%) and absence of the pfmdr1 N86Y mutant allele, indicating persistent chloroquine resistance markers despite drug withdrawal. These findings highlight the need for continued molecular surveillance and strengthened malaria diagnosis and treatment monitoring in Ethiopia.
Effect of Failure of Passive Transfer of Immunity on Crude Morbidity and Mortality in Dairy Calves
(2007-06) Ahmed Ibrahim; Alemayehu Lemma
A longitudinal prospective observational study on the concentrations of serum total protein (STP), as a measure of status of passive immunity, and its associations with crude calf morbidity and mortality in dairy farms in Debre Zeit and its surroundings was conducted from October 6, 2006 to May 15, 2007, with the objectives of determining the proportions of calves with failure of passive transfer (FPT) of immunity, describing the incidence rates of crude morbidity and mortality, and investigating the associations of the status of passive transfer of immunity with crude morbidity and mortality in the newborn dairy calves. A total of 354 crossbred dairy calves were included in the study. Serum samples were collected when the calves were from 24hrs to one week of age, and regularly monitored for clinical outcomes (morbidity and mortality) up to the age of six months. The mean STP concentration as measured during the first week of life was 66.4+16.6g/L and the values ranged from 28.8 to 99.8g/L. The proportion of calves with FPT, (where the STP concentrations were less than or equal to 55g/L) was found to be 30.23%. The overall incidence rate of crude morbidity and crude mortality found in this study were 52.3% and 18.9% respectively. A total of 21 potential risk factors were investigated for their associations with FPT, crude morbidity and crude mortality. Among these 9 variables that were considered for their effect on the status of passive transfer, 7 were found to be statistically significantly associated with FPT. Further analysis of these factors using logistic regression indicated that only 4 factors, age of the dam as represented by parity number (OR = 14.6, 95% CI = 6.27-33.84), age at first colostrum ingestion (OR = 7.2, 95% CI = 2.56-20.13), attendant at parturation (OR = 4.4, 95% CI = 1.48-13.10) and sex of the calf (OR = 3.8; 95% CI= 1.61-8.83) were significantly associated with FPT. Univariate analysis of 10 risk factors of crude morbidity showed that 6 factors were significantly associated with crude morbidity, but on multivariate analysis, only STP (OR = 11, 95% CI = 4.4-27.4) and attendant at birth (OR = 2.7, 95% CI = 1.3-7.2) had significant interaction in causing morbidity. Similarly, Cox regression model indicated that STP (p< 0.001), attendant at birth (p< 0.05), age at first colostrum ingestion (p< 0.05) and birth condition (p< 0.05) were significantly viii associated with earlier age at the onset of crude morbidity. The effect of FPT on crude morbidity was further analyzed by partitioning the crude morbidity into 8 STP strata and the highest incidence rates of crude morbidity (>95%) were observed in calves with STP concentrations < 55g/L, but a remarkable drop of crude morbidity was seen in calves with STP concentrations >65g/L. On the other hand, the greatest relative risk (RR = 2.5, 95% CI = 2.07-2.93) of crude morbidity were observed in calves with STP concentrations of < 55g/L. Out of 11 risk factors of crude mortality, 9 were showed significant association on univariate analysis, but when adjusted for their interaction, only age at the onset of morbidity (OR = 27.2, 95% CI = 7.6-97.1), STP (OR = 3.1, 95% CI = 1.4-9.2) and sex (OR = 2.7, 95% CI = 1.3-5.7) were found to be significantly associated with crude mortality. Similarly, Proportional Hazard (Cox) Regression showed that age at the onset of morbidity (p< 0.001), STP concentrations (p< 0.001), sex (p< 0.05) and time of birth (p< 0.05) were significantly associated with mortality at an earlier age of the calf. Furthermore, the highest incidence rate of crude mortality was observed in calves with STP concentrations < 55g/L, while the greatest relative risk (RR = 5.3, 95% CI = 3.73-7.56) of crude mortality was experienced by calves with STP concentrations < 35g/L. Calves with STP concentrations of 35.1-45.0 and 45.1-55.0g/L had lower relative risk (RR = 2.2, 95% CI = 1.32-3.81 and 2.9, 95% CI = 1.86-4.39, respectively) of crude mortality compared to calves with STP concentration < 35g/L. The optimum survival was observed in calves with STP concentrations > 55g/L with insignificant relative risk of crude mortality. Thirty three percent of the total death was attributed to FPT. Calves with lower STP values due to FPT of colostral immunity had increased risk of death and measuring the degree of passive transfer of colostral immunity at the first week of age was very important to proper management of young calves.

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