Veterinary Public Health

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A cross-Sectional Study on Salmonella in Apparently Healthy Slaughtered Sheep and Goats at Addis Bbaba and Modjo Abattoirs, Ethiopia
(Addis Ababauniversity, 2004-06) Molla, Wassie; Molla, Bayleyegn (PhD)
The present study was undertaken on apparently healthy slaughtered sheep and goats, and apparently healthy abattoir personnel at Addis Ababa public and Modjo modern export abattoirs from September, 2003 to February, 2004. The objectives of the study were to determine the prevalence and distribution of Salmonella in sheep and goats and abattoir personnel, to identify and characterize the prevalent Salmonella serotypes and to determine the antimicrobial resistance of Salmonella isolates to selected antimicrobial agents. A total of 1224 samples consisting of faeces (n=204), mesenteric lymph nodes (n=204), liver (n=204), spleen (n=204), abdominal (n=204) and diaphragmatic muscles (n=204) samples from 104 sheep and 100 goats and 117 stool samples from abattoir personnel were collected. The samples were examined for the presence of Salmonella following the techniques recommended by the International Organization for Standardization (ISO 6579, 1998). Salmonellae were isolated from 12 of 104 (11.5% (95% CI = 6.1-19.3)) sheep and 3 of 100 (3% (95% CI = 0.6-8.5)) goats and none of the samples from abattoir personnel were positive for Salmonella. The frequency of isolation and distribution of Salmonella in different tissue and faecal samples of sheep and goats was analyzed. Of the total 624 samples examined from apparently healthy slaughtered sheep, 18 (2.9%) were Salmonella positive. Salmonellae were isolated from 4.8% faecal, 7.7% mesenteric lymph nodes, 1.9% liver and 1.9% abdominal muscle samples. Only one isolate was found from spleen and Salmonella was not detected from diaphragmatic muscle samples. Four (0.7%) Salmonella positive samples were detected from a total of 600 samples from apparently healthy slaughtered goats. Salmonella was isolated from 2% faecal and 2% mesenteric lymph nodes samples whereas in other organs Salmonella was not detected. In both species, the number of positive specimens was higher for faeces and mesenteric lymph nodes samples than others. Serotypes and phage types of Salmonella strains isolated from sheep and goats were identified. All the 22 Salmonella isolates were serotyped and serotypes of S. Typhimurium, S. Heidelberg, S. Typhimurium var. Copenhagen and S. Enteritidis strains were further phage typed. A total of 9 different serotypes were identified from sheep (n=7) and goats (n=3), of which S. Typhimurium (36.4%) and S. Heidelberg (18.2%) were the most prevalent serotype followed by S. Give, S. Poona and S. Reading (each 9.1%). Other serotypes including S. Typhimurium var. Copenhagen, S. Enteritidis, S. Niederoderwitz and S. I: 6, 7, 14:-: enz15 were also detected from sheep and goats. The most common serotypes recovered in sheep were S. Typhimurium (38.9%) and S. Heidelberg (22.2%) and in goats it was S. Poona (50.0%). Three serotypes, S. Poona, S. I: 6, 7, 14:-:enz15 and S. Niededrowtiz were reported for the first time in Ethiopia. The phage types identified include S. Typhimurium phage type 46, S. Typhimurium phage type 193, S. Typhimurium phage type 2, S. Typhimurium phage type 79, S. Typhimurium phage type U285, S. Typhimurium var. Copenhagen phage type 104, S. Enteritidis phage type 5a and S. Heidelberg phage type atypical. Of which S. Heidelberg phage type atypical was the most common phage type in sheep. Salmonella Typhimurium phage type 46 was the most prevalent phage type of S. Typimurium phage types in sheep whereas S. Typhimurium phage type 193 was found both in sheep and goats. All isolates were tested for susceptibility to a group of 24 selected antimicrobials. Out of the 22 isolates tested, 7 (31.8%) were multiple resistant from two to up to nine antimicrobials. Among the isolates, only S. Typhimurium (62.5%) and S. Reading (100%) displayed multiple resistances to ten different antimicrobials. Salmonella Typhimurium isolates were resistant to ampicillin and cephalothin (each 50.0%), sulfisoxazole, streptomycin, sulfamethoxazol-trimethoprim and trimethoprim (each 25.0%), amoxicillin/clavulanic acid, chloramphenicol, spectinomycin and tetracycline (each 12.5%). However, S. Reading isolates showed resistance only to streptomycin, sulfisoxazole and tetracycline (each 100%). The results of this study showed the potential risk of sheep and goats as sources of pathogenic and multi-drug resistant Salmonella serotypes for humans in the study area. This is a significant threat to public health particularly to those who have direct or indirect contact to sheep and goats and consumers who have the habit of eating sheep and goats meat or meat products either raw or under cooked. These findings stressed the need for implementation of Salmonella control and prevention strategies from farm production to consumption of animal and animal products. Key words: Sheep, goats, abattoir personnel, Salmonella, serotypes, prevalence, antimicrobial resistance, Addis Ababa, Modjo
CAMEL MASTITIS AND ITS IMPACT ON QUALITY OF MILK IN GEWANE WOREDA, AFAR REGIONAL STATE, ETHIOPIA
(2007-06) FASIL, MENGISTU; Dr. Bayleyegn Molla
Quarter milk samples (n = 404) from 101 traditionally managed lactating camels (Camelus dromedarius) in Gewane district of Afar region were examined to estimate the prevalence of mastitis, identification of bacterial causes associated with mastitis and determine fat and protein content of camel milk. Twenty one of the 101 (20.8%) camels examined were diagnosed as mastitis cases based on clinical signs. Thirty one of the 101 camels (30.7%) udders examined were infested with ticks and had lesion on the teats and udder skin, 45.2% had mastitis. There were significant association (p< 0.05) between tick infestation and mastitis. Lactating camels at early and mid lactation were found most affected by mastitis (p<0.05) than those at late lactation. One hundred ninety six of the 404 camel quarter milk samples (48.5%) were positive for California mastitis test (CMT). Out of 196 positive quarter milk samples, 164 (83.7%) yielded pathogenic bacteria. A positive correlation (r = 0.76) was observed between CMT positive results and presence of major pathogens in camel milk samples. The main mastitis pathogens isolated were Staphylococcus aureus, Coagulase-negative staphylococci, Streptococcus agalactiae, Streptococcus dysgalactiae and other Streptococcus species, E.coli, Micrococcus species, corynebacterium, Actinomyces species Pasteurella haemolytica and Bacillus species. Twenty CMT-positive and CMT-negative pooled quarter milk samples each were evaluated for fat and protein content. The average mean fat and protein percentage in CMT-negative milk were 3.83% ± 0.081 and 2.85 ± 0.024 respectively. However, in CMT-negative milk it was 1.97 ± 0.071 and 2.91± 0.13 respectively. Fat percentage were lower in all parity number and stage of lactation but it was not statistically significant (p>0.05). Protein percentage were significantly higher in CMTpositive milk samples in different parity (p<0.05). The present study results suggest that mastitis in camels was prevalent in Gewane district of Afar Regional State, North Eastern Ethiopia. California mastitis test has shown to be valuable indicators of udder infection of camels. Gram positive cocci were the dominant species among mastitis pathogens isolated. Tick infestation together with thorny bushes, use of anti-suckling devices and teat or udder lesions were found predisposing factors to the occurrence of mastitis. Although camels in the Afar pastoralist are managed traditionally on poor quality feed and scarce water source, the protein and fat content of the milk were in the normal range. Slight alterations in fat and protein contents were observed in CMT-positive milk samples
ESCHERICHIA COLI O157:H7 ISOLATION FROM FECES, SKIN AND CARCASSES AS WELL AS TOTAL AND FECAL COLIFORMS ON CARCASSES OF SMALL RUMINANTS AT AN EXPORT ABATTOIR, MOJDO, ETHIOPIA
(2008) GASHAW, MERSHA; Dr. Moses N. Kyule, Dr. Daniel Asrat
The purpose of this study was to find out the presence of association between carcass contamination with E. coli O157: H7 and fecal and skin prevalence of E. coli O157: H7 and to estimate coliform loads on before and after wash of sheep and goats carcasses at an export abattoir at Modjo, Ethiopia. A total of 711 samples were examined for the presence of E. coli O157:H7 from fecal samples, skin swabs, carcass swabs before and after wash from sheep and goats slaughtered between October, 2007 and April, 2008. Water samples were also collected for the isolation of E. coli O157:H7 and coliform counts. Total and fecal coliform loads were estimated on same carcasses using Violet Red Bile Agar (VRBA). For the isolation of E. coli O157:H7, all samples were enriched with modified Tryptic Soy broth with novobiocin (mTSB+n) and concentrated using immunomagnetic separation (IMS). The bacteria-bead complex was plated onto cefixime-tellurite containing Sorbitol MacConkey agar (CT-SMAC) and presumptive colonies were confirmed by latex agglutination test as recommended by ISO16654, (2001). E. coli O157:H7 was isolated from feces (4.7%), skin swabs (8.7%), carcass swabs before wash (8.1%), carcass swabs after wash (8.7%) and water samples (4.2%), respectively. A statistically significant association was found between prevalence of carcass contamination with fecal and skin E. coli O157:H7 status. The total coliform counts before and after carcass wash were 3.15 log10CFUcm-2 (SD= 0.77) and 2.97 log10CFUcm-2 (SD = 0.82), respectively. The log10 means of fecal coliforms before and after carcass wash were 2.96 (SD=0.88) and 2.77(SD=0.91) respectively. Statistically significant difference was observed between the means of total coliform counts (P=0.002) and fecal coliform counts (P=0.001) before and after carcass wash. No fecal coliforms were isolated from water samples. PCR analysis identified both stx1 and stx2 genes from one E. coli O157:H7 isolate collected from goat carcass. The identification of this virulent factor indicates the potential of sheep and goats as sources of E.coli O157:H7 for human infection in the country. Control measures to reduce the public health risks arising from E. coli O157 in reservoir animals must be addressed at abattoir levels by reducing skin and fecal sources and carcass contaminations at different stage of slaughter operations. Applications of HACCP system are strongly recommended at the abattoirs.
SEROPREVALENCE STUDY OF TOXOPLASMOSIS IN SMALL RUMINANTS AND HUMANS (HIV/AIDS PATIENTS) IN SELECTED DISTRICTS OF SOUTH WOLLO, ETHIOPIA
(2008-06) YIBELTAL, MUHIE; Dr. Moses Kyule, Dr. Teshale Sori; Dr. Arega Firew
Toxoplasma gondii has been known to be responsible for abortion, still birth and birth of weak offsprings in susceptible hosts such as sheep and goats and cause subsequent economic losses. The parasite also emerged as a serious opportunistic infection associated with acquired immune deficiency syndrome (HIV/AIDS) in humans. A cross-sectional study on toxoplasmosis in small ruminants and humans (HIV/AIDS patients) were conducted in selected districts of South Wollo, Ethiopia between October 2007 and April 2008. Serological survey of antibodies to T. gondii was carried out using modified Direct Agglutination test (MAT) on sheep, goats and humans. Of 426 sheep and 86 goats serum samples analyzed, 45.4% and 37.2% of sheep and goats respectively were found to be positive for anti-T. gondii IgG. Higher seroprevalence of toxoplasmosis 49.2% was recorded in Legambo Woreda than in Dessie Municipality Abattoir 28.9%. The sex and age-specific prevalences were found to be higher in females and older animals than in males and younger ones in both species. History of abortion, neonatal mortality and weak births were significantly associated in sheep (P= 0.000) associated with toxoplasmosis and abortion was the most common problems in sheep and goats in the study area. Of the 260 human serum samples analyzed by Modified Direct Agglutination Test (MAT), seropositivity to toxoplasmosis was found in 76.5%. Out of all of HIV-positive sera, 89.6% were positive for anti-T. gondii IgG. There was significant association between seroprevalence of toxoplasmosis and HIV infection (P= 0.000). The risk factors associated with seropositivity to Toxoplasma infection were consumption of raw/under cooked mutton (P= 0.001) and presence of cat (P= 0.038) in the house holds and more than 68% of the respondents had a history of consumption of raw meat and 25% had close contact with cats. The high seroprevalence of T. gondii antibodies found in the present study suggested widespread exposure of sheep, goats and humans to T. gondii. Therefore, economic impact of toxoplasmosis in small ruminants should be investigated in detail and early detection of the presence of toxoplasmosis in HIV/ADIS patients is helpful for the initiation of early treatment schemes. Veterinarians should provide advice on possible minimization of contact with cats and avoidance of eating raw or undercooked meat.
SERO-PREVALENCE STUDY OF BRUCELLOSIS IN CATTLE AND HUMANS IN DIBATE AND WEMBERA DISTRICTS, METEKELE ZONE, BENISHANGUL GUMUZ REGION
(2008-06) KASSAYE, ERKIHUN; Dr. Girma Zewde, Dr.Getahun Ejeta
A cross-sectional study was conducted in Debate and Wembera districts of Metekele Administrative Zone, Benishangul Gumuze Regional State, between October 2007 and March 2008, 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 technique was employed, by which 12 peasant associations were identified as primary units and 164 individual cattle owners as secondary units. Accordingly, 1152 cattle (164 herds) were sampled. In the sampling, all cattle in the herd above 6 months of age were included. Human risk groups were sampled using purposive sampling method. The study methods involved collection of serum sample, questionnaire surveys and serological tests. 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 herd was said to be positive if at least one animal reacts positively by both RBPT and CFT. The overall individual cattle and herd sero-prevalence of bovine brucellosis the study area were 1% (11/1152) and 4.9 % (n= 8/164), respectively. Within herd sero-prevalence ranged between 0% and 15.4%, While considering only positive herds (n=8), it varied from 5.3%- 15.4%. Both univariable logistic regression and multivariable logistic regression analyses showed that the risk of sero-positivity was increased by increases herd size of the animal (p=0.000, OR=1.34). Brucellosis sero-positivity was statistically different among cattle, which experienced abortion than those, which did not (OR= 6.6, P = 0.013). The reproductive status (lactation, pregnancy, dry cow and heifer) did not show significant difference in the rate of sero-prevalence among the four reproductive statuses. Multivariable logistic regression analysis showed that, the age of cattle was not significantly associated with sero-positivity (P=0.205). With univariable, logistic regression analysis sex was not found to be significantly associated with sero-positivity of cattle in the study area (p=0.994), even though all positive cattle were females. XIII All sampled human serums were found negative for Brucella antibodies. Risk factors are discussed; conclusions are drawn and pertinent recommendations are forwarded.
Bovine tuberculosis: Epidemiologic aspects and public health implications in and around Debre Birhan, Ethiopuia
(2008-06) Shihun, Shimelis; Dr. Gezahegne Mamo, Dr. Gobena Ameni,
A cross-sectional study to assess the epidemiology and zoonotic implication of bovine tuberculosis (BTB) was conducted on 1055 cattle in and around Debre Birhan between December 2006 and October 2007 using a comparative intradermal tuberculin (CIDT) test, abattoir surveillance, bacteriology and molecular typing. Besides, 140 livestock owners were interviewed for the evaluation of the zoonotic potential of BTB. On the basis of the CIDT test, animal and herd prevalence were 2.7% (14/524) and 9.3% (13/140), respectively, while in abattoir-based study the prevalence was 22% (117/531). Male animals were more likely (OR= 1.7; P=0.012; 95% CI: 1.12, 2.55) to exhibit tuberculous lesions as compared to female animals. The proportion of culture positivity was 32% (40/125) in tissue samples. But, because of the scarcity of molecular facilities, only nine isolates were typed in Veterinary Laboratory Agency (VLA), United Kingdom. Out of these, seven isolates were positive for the genus Mycobacterium of which two were identified as M. tuberculosis. The two M. tuberculosis species had the same spoligotype pattern. Awareness of cattle owners about BTB was poor (25.7%) and thus cattle owners were found to consume raw milk, soured milk product (yoghurt) and raw meat. A total of 3407 TB patients received short course therapy in health institutions found in Debre Birhan with in five years, of which 79.9% (2723/3407) were between 15 to 50 years. Thus, detection of BTB both in live and slaughtered animals, lower awareness of cattle owners about the disease and the prevailing habit of consumption of animal products would suggest the potential role of BTB as a zoonosis, while the isolation of M. tuberculosis from animal tissues warrants the existence of transmission of this agent from humans to animals. Therefore, practical and sound control methods such as strict meat inspection, boiling of milk and cooking of meat, and public education to raise the awareness on the transmission of the disease are recommended.
Escherichia Colio157H7 in Fecesskin and Carcasses as wall as Total and Fecal Coliforms on Arcasses of Small Ruminants at an Export Abattoir Mojdo Ethiopian
(Addis Ababa University, 2008-06) Mersha, Gashaw; Abdella, Mohammed(PhD)
The Purpose of this Stud was to Fin out the Presence of Association Between Carcass Contamination
Seroprevalence Study of Bovine Brucellosis and its Public Heath Significance in Western Tigray, Ethiopia
(Addis Ababa University, 2008-06) Haileselassie, Mekonnen; Kyule, Moses (phD)
A Cross Sectional Study Was Conducted to Determine The Seroprevalence and Associations With Potential Risk Factors of Brucellosis in Cattle and Humans in Western Zone of Tigray Regional State Between October 2007 and February 2008. A Two-Stage Cluster Sampling Method Was Used in This Study. A Total of 1968 Cattle Were Examined. of These 1120 Cattle Were Examined From Semiintensive Production System and 848 Cattle From Extensive One. Human Risk Groups To Brucellosis Were Purposively Sampled. Sera Sampling Was Carried Out From all Cattle Above Six Months of Age With No History of Previous Vaccination Against Brucellosis. The Types of Tests Used to Detect The Presence of Brucella Antibodies Were Rose Bengal Plate Test And Complement Fixation Test. The Overall Individual Animal Prevalence Was 4.9%. There Were High Significant Differences (P=O.OOO) in Seroprevalence To Brucella Antibody Between Semi-Intensive And Extensive Production Systems. The Seroprevalence To Brucella Antibodies Among Nine Towns In The Semiintensive and The Three Districts (Hmera, Tsegede And Welkait) at Both Individual and Herd Levels In The Extensive Production System Were Comparable. Seroreactor in Both Sexes of Cattle Were Varied Significantly. Females Were More Infected. Seroprevalence by Categories of Ages and Herd Sizes Were Significantly Different. Higher Risk to Infection Was Found in Barka Breeds Than Arado In The Semi-Intensive Production System But Not in The Extensive Production System. History of Abortion Was Found Significantly (P=0.001) Associated With Brucellosis. Watering Points and Culling Methods of Management and Husbandry Related Factors Were Significantly Associated With Seropositivity to Brucellosis and Brucellosis Increased The Calving Intervals. in A Total Of 246 Vulnerable Groups of Humans to Brucellosis 1.2% Overall Seropositive To Brucella Antibodies Were Obtained With all Positive Reactors Being Herdsmen. There Was A High Risk of Acquiring The Infection During Removal of Retained Fetal Membranes and in Those Who Were Both in Contacts With Animals and Drank Raw Milk. A High Prevalence of Brucellosis In Barka Breeds in The Study Area Indicates That It Might Serve As Source of Infection For Others in The Region. Hence, Before Distributipg This Breed Screening Test For Brucellosis Is Recommended. While In Case of Human Brucellosis, Since Its Presence Is Confirmed and The Risk Factors Were Identified, The Medical Personnel Should Give Attention to Its Differential Diagnosis With Aims of Offering Specific Therapies To True Cases And Creating Awareness Via Education Campaigns to Human Risk Groups. Vlll Key Words: Breed, Cattle, Cross-Sectional Survey, Brucellosis, Human, Production System, Risk Factors, Western Tigray
ZOONOTIC IMPORTANCE OF HYDATIDOSIS IN CATTLE AND HUMANS IN SELECTED AREAS OF TIGRAY REGIONAL STATE
(2008-06) KEBEDE, WOLDEGIORGIS; Dr. Girma Zewede, Dr. Hagos Ashenafi
DETECTION AND DETERMINATION OF OXYTETRACYCLINE AND PENICILLIN G ANTIBIOTIC RESIDUE LEVELS IN BOVINE BULK MILK FROM DEBREZEIT AND NAZARETH DAIRY FARMS
(2008-06) DESALEGNE, ABEBEW; Dr. Moses Kyule, Dr. Kelay Belihu; Dr. Girma Zewda, Dr. Tadelle Dessie
A cross-sectional study was conducted between October 2007 and May 2008 to detect and determine oxytetracycline and penicillin G residue levels in bulk milk of cows in Debre Zeit and Nazareth dairy farms. A total of 400 bulk milk samples were randomly collected from the respective study dairy farms. A questionnaire survey was carried out by personal interviews with dairy farm owners in Delvotest positive farms (cases) and Delvotest negative farms (controls) to identify various risk factors and to determine associations among the occurrence of antibiotic residues in milk. All samples were qualitatively screened for antibiotic residues by Delvotest SP assay. Concentration of the positive samples was determined by high performance liquid chromatography. Concentration was established using linear calibration reference curves. Out of 400 samples analyzed for antibiotic residues, 46 (11.50%) had detectable antibiotic residues. In Debre Zeit dairy farms, 34 (12.19%) and in Nazareth, 12 (9.92%) milk samples were positive for antibiotic residues. The mean residue level of oxytetracycline was 142.00μg/l and 125.25μg/l in Debre Zeit and Nazareth dairy farms and that of penicillin G was 4.77μg/l and 4.52μg/l in the two dairy farms, respectively. Oxytetracycline concentratyions in all samples in Debre Zeit and Nazareth dairy farms ranged at a concentration between 27-251μg/l and 45-192 μg/l, respectively. The antibiotic residues positive samples which showed residue of oxytetracycline above the WTO/FAO/CAC established maximum residue limit of 100gμ/l were 24 (70.58%) and 10 (83.33%) in Debre Zeit and in Nazareth dairy farms, respectively. For penicillin G with maximum residue limit of 4μg/l, they were 7 (20.58%) and 2 (16.66%) in Debre Zeit and Nazareth dairy farms, respectively. Penicillin G was found in some milk samples in Debre Zeit 19(58.8%) and Nazareth 5(41.7%) dairy farms. The results obtained confirmed that oxytetracycline and penicillin G were imprudently used in dairy farms. Results of the present study serve as preliminary base-line information for veterinary authorities, drug administration and quality control, other concerned organizations and professionals to take necessary measures in controlling and preventing of occurrence of drug residues in milk and other food products.
AN EPIDEMIOLOGIC STUDY OF CRYPTOSPORIDIOSIS AND ITS POTENTIAL RISK FACTORS IN DIARRHOEIC CALVES AND HIV/AIDS PATIENTS IN AND AROUND HAWASSA, ETHIOPIA
(2008-06) Etsehiwot, Wondimu
Cryptosporidiosis is an important disease in both animals and in immunocompromised individuals especially those with HIV/AIDS. C. parvum is the most important zoonotic pathogen, mostly transmitted from calves but other zoonotic Cryptosporidium spp. like C. meleagridis, C. felis, C. canis, C. muris, C. suis can also be found to be important opportunistic infection in HIV/AIDS patients. The epidemiology of cryptosporidiosis in humans is not well understood due to the existence of multiple transmission pathways such as person-to-person, animal-to-person, waterborne, food-borne, and possible airborne transmission, which limits the implementation approaches like prevention, and control of the disease. In this study, the prevalence and potential risk factors of cryptosporidiosis in calves and HIV/AIDS patients were determined. The results of this study indicated that the prevalence of cryptosporidiosis among HIV/AIDS patients attending Hawassa Referral Hospital for gastro-intestinal illness with diarrhoea was 43.9% by modified acid-fast staining procedure. Among the positive samples for Cryptosporidium spp., C. felis and C. canis were found to be 3% and 1% respectively based on oocyst sizes while; other Cryptosporidium oocysts were undifferentiated because of similarities in oocyst sizes. The presence of diarrheic calves and animal contacts were significantly associated (p<0.05) with human cryptosporidiosis. Other factors like education, sex, water sources and the presence of diarrheic individuals at homes were not (p>0.05). Among the 62 individuals with direct contacts with diarrheic calves, the calves were found to be risk factors (OR= 5.227). The prevalence of cryptosporidiosis due to C. parvum in sampled diarrheic calves of age less than six months was 39.4%. Chi square test were done to see if there is association between risk factors and ELISA result. Results showed that housing, water source, feeding, animal wastes disposal and production systems were significantly associated (p<0.05) with calf cryptosporidiosis due to C. parvum. Based on this study results, contacts with cattle and diarrheic calves were identified as the most important risk factors for cryptosporidiosis in HIV/AIDS individuals.
ISOLATION, PREPARATION AND EFFICACY TRIAL OF ADJUVATED FORMALIN INACTIVATED FOWL CHOLERA VACCINE FROM LOCAL ISOLATES OF PASTEURELLA MULTOCIDA IN LAYER CHICKENS
(2008-06) MOLALEGNE, BITEW; Dr. Moses Kyule, Dr. Kelay Belihu; Dr. Berhie Gebre-Egziabher
Crossectional and experimental studies were undertaken with the objectives of isolating, producing and efficacious trials of adjuvated formalin-killed fowl cholera vaccine from local isolates of P. multocida on layer chickens at the Department of Vaccine Production and Microbiology laboratory of the National Veterinary Institute in collaboration with Addis Ababa University, Faculty of Veterinary Medicine between September 2007 and May 2008. The study used 384 chickens having typical clinical signs of fowl cholera from commercial poultry farms and backyard poultry to detect P. multucida. A total of 300 Bovans Gold-line breed layer chickens were used for the experimental trial. A total of 3 local isolates of Pasteurella multocida (Kombolch state farm, Genesis Farm and Tadesse Farm) were identified and characterized from the natural fowl cholera out-breaks. The best growth of the isolates was in the dextrose starch agar with 5% chicken serum. All the isolates were studied for their virulence in chickens at the age of 4 weeks and found that Kombolcha State Farm isolate was highly virulent with a mortality of 100% and mortality rate of 2 chicken-day-at risk, followed by Genesis Farm isolate with a mortality of 90% and a mortality rate 1.63 chicken-day -at risk. The least virulent isolate was from Tadesse Farm, which showed no mortality. Three adjuvanted (Montanide ISA 50, Al (OH) 3 and AlK (SO4) 2) formalin inactivated fowl cholera vaccines were prepared using three doses of bacterial loads (106, 109and 1012) from Kombolch State Farm isolate. The efficacy performances of these vaccines were evaluated and compared with each other. There were significant differences in geometric means of the antibody IHA titers between bacteria doses of 106, 109and 1012. The dose level of 1012 CFU elicited highest antibody response followed by 109 and 106. The three kinds of adjuvants used did not significantly differ in levels of immune responses. This study found that there was association between IHA log10 titers with bacteria doses (loads) and adjuvants. The linear regression indicated that the IHA log10 titers were associated with bacterial doses used. Multivariable correlation matrix showed very strong associations between IHA log10 titers and bacteria loads (r = 0.729). This correlation was significant. The experimental challenge protection test indicated that double doses of Aluminium potassium sulphate and Montanide ISA 50 adjuvanted vaccines gave better geometric mean antibody IHA titers and better protection (PI= 91.6% for both vaccines) as compared with aluminium hydroxide adjuvanted vaccine with PI = 83.9%. In the unvaccinated control groups 86% of mortality was recorded. This study XII indicated that AlK (SO4) 2 adjvanted vaccine at a bacterial dose of 1012 gave better IHA titers in comparison with other adjuvant and bacterial load vaccines. Although inactivated fowl cholera vaccines have been produced in other countries, the poultry enterprises in Ethiopia continue to experience problems associated with the disease due to unavailability of cost-effective vaccines. To alleviate this problem, the adaptation of this technique used in this trial with eventual production of the vaccines at the National Veterinary Institute is highly recommended.
SEROPREVALENCE STUDY OF BOVINE BRUCELLOSIS AND ITS PUBLIC HEATH SIGNIFICANCE IN WESTERN TIGRAY, ETHIOPIA
(2008-06) MEKONNEN, HAILESELASSIE; Dr. Moses Kyule, Dr. Kelay Belihu; Dr. Shewit Kalayou
A cross sectional study was conducted to determine the seroprevalence and associations with potential risk factors of brucellosis in cattle and humans in western zone of Tigray Regional State between October 2007 and February 2008. A two-stage cluster sampling method was used in this study. A total of 1968 cattle were examined. Of these 1120 cattle were examined from semi-intensive production system and 848 cattle from extensive one. Human risk groups to brucellosis were purposively sampled. Sera sampling was carried out from all cattle above six months of age with no history of previous vaccination against brucellosis. The types of tests used to detect the presence of Brucella antibodies were Rose Bengal Plate Test and Complement Fixation Test. The overall individual animal prevalence was 4.9%. There were high significant differences (P=0.000) in seroprevalence to Brucella antibody between semi-intensive and extensive production systems. The seroprevalence to Brucella antibodies among nine towns in the semi-intensive and the three districts (Hmera, Tsegede and Welkait) at both individual and herd levels in the extensive production system were comparable. Seroreactor in both sexes of cattle were varied significantly. Females were more infected. Seroprevalence by categories of ages and herd sizes were significantly different. Higher risk to infection was found in Barka breeds than Arado in the semi-intensive production system but not in the extensive production system. History of abortion was found significantly (P=0.001) associated with brucellosis. Watering points and culling methods of management and husbandry related factors were significantly associated with seropositivity to brucellosis and brucellosis increased the calving intervals. In a total of 246 vulnerable groups of humans to brucellosis 1.2% overall seropositive to Brucella antibodies were obtained with all positive reactors being herdsmen. There was a high risk of acquiring the infection during removal of retained fetal membranes and in those who were both in contacts with animals and drank raw milk. A high prevalence of brucellosis in Barka breeds in the study area indicates that it might serve as source of infection for others in the region. Hence, before distributing this breed screening test for brucellosis is recommended. While in case of human brucellosis, since its presence is confirmed and the risk factors were identified, the medical personnel should give attention to its differential diagnosis with aims of offering specific therapies to true cases and creating awareness via education campaigns to human risk groups.
STUDY ON THE PREVALENCE OF THERMOPHILIC CAMPYLOBACTER SPECIES IN SHEEP AND GOAT CARCASSES AT HELIMEX EXPORT ABATTOIR
(2008-06) TEFERA, WOLDEMARIAM; Dr. Girma Zewde, Dr. Daniel Asrat; Dr. Getahun Ejeta
Campylobacter jejuni and C. coli are frequent worldwide causes of food-borne gastroenteritis in humans. A study on the prevalence of thermophilic Campylobacter species from the carcasses of slaughtered sheep and goats was undertaken at Hashim Nuru Jiru Ethiopia livestock and meat import-exporter (HELMIX) export abattoir in Debre-Zeit, Ethiopia from November 2007 to April 2008. A total of 218 sheep and 180 goat carcasses (398 total carcasses) were examined from carcass swabs taken from crutch, abdomen, thorax and breast areas. From each slaughtered animal, carcass swab was taken only from one of these sites on the carcass but each swabbing site was swabbed for three different operations in the abattoir namely before evisceration, after evisceration and after washing. A total of 654 swab samples were collected from 218 sheep carcasses comprised of 56 crutch swabs, 49 abdomen swabs, 50 thorax swabs and 63 breast swabs before evisceration, after evisceration and after washing. Similarly, 540 swabs from 180 goat carcasses were collected consisting of 52 crutch swabs, 46 abdomen swabs, 42 thorax swabs and 40 breast swabs from each of the three slaughter operations. Thus from the three operations a total of 1194 swabs were analyzed. Bacteriological analysis of the samples was conducted in the Microbiology laboratory, Faculty of Veterinary Medicine, Debre-Zeit following the techniques recommended by the International Organization for Standardization (ISO, 2002). From a total of 398 carcasses examined, 40 carcasses were positive for Campylobacter with contamination rate of 10%. Per contamination rate with either C. jejuni or C. coli were 10.6% (n=218) and 9.4% (n=180) for sheep and goat carcasses, respectively. However, statistically significant difference was not detected in the rate of carcass contamination between sheep and goat carcasses (p=0.72). The most prevalent thermophilic Campylobacter species recovered from the sheep and goat carcasses was C. jejuni accounting for 7.3% (n=398), followed by C. coli 2.7% (n= 398). Out of the 40 positive samples the proportion of the Campylobacter species was 72.5% and 27.5% for C. jejuni and C. coli respectively. This variation in the isolation rate between the two Campylobacter species was statistically significant (P=0.003). Though there was no statistically significant difference (P=0.57) in the rate of carcass contamination among the four swabbing sites, the highest contamination rate was observed in the breast area at a rate of 12.6% (n=103) followed by abdomen with contamination rate of 11.6% (n=95). Highest rate of carcass contamination was observed after evisceration as compared to prior evisceration and after x washing (p=0.000). Washing of the carcass did not reduce carcass contamination in the slaughtered sheep (2=0.18; P=0.68), however there was a substantial reduction in the level of carcass contamination after washing in goat carcasses ((2=10.72; P=0.001). The present study revealed the existence of severe cross contamination during slaughter operations particularly during evisceration. Carcass contamination by Campylobacter can be reduced, and thus its public health impact, through good hygienic practices in the abattoir.
EPIDEMIOLOGY AND ECONOMIC IMPORTANCE OF FASCIOLOSIS OF DOMESTIC RUMINANTS IN SELECTED SITES OF TIGRAY REGIONAL STATE, NORTHERN ETHIOPIA
(2008-06) GEBRU, LEGESSE; Dr. Yilkal Asfaw, Dr. Yacob Hailu,
A 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.
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; Dr. Yilkal Asfaw, Dr. Mesfin Sahle,
Seven 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.
Study on the Contamination Rate of Sheep and Goat Carcasses with Campylobacter Species at Exportrt Abattoir
(Addis Ababa University, 2008-06) Woldemariam, Tefera; Zcwdc, Girma (phD)
Campy/obaeter jejlmi and C. coli arc frequent worldwide causes of footl-borne gastroenteritis in humans. A study on the prevalencc of thcrmophilic Celllifly/obaeter specics frum thc carcusses of slaughtered sheep and goats were undertaken at Hashim Nuru Jiru Ethiopia livestock and meat import-exporter (HELM IX) export abattoir in Oebre-Zeit, Ethiopia from November 2007 to April 2008. A total of 218 sheep and 180 goat carcasses (398 totul sumplcs) were cxamincd fcoin carcass swabs taken from crutch, abdomcn, thorux and breust areas. Frum. cuch slaughtcred animal, carcass swab was taken only from one of these sites on the carcass but each swabbing site was swabbed for three different operations in the abattoir namely before evisceration, after evisceration and after washing. A total of 654 swab samples were collected from 218 sheep carcasses comprised of 56 crutch swabs, 49 abdomen swabs, 50 thorax swabs and 63 breast swabs before evisceration, after evisceration and after. washing. Similarly, 540 swabs from 180 goat carcasses were collected consisting of 52 crutch swabs, 46 abdomen swabs. 42 thorax swnbs and 40 breast swabs from each of the three slaughter operations. Thus from the three operations a total of 1194 swabs were analyzed. Bacteriological analysis of the samples was conducted in the Microbiology laboratory, Faculty of Veterinury Medicine, Dehre-Zcit flllluwing the techniques recommended by the International Organization for Standardization (ISO, 2002). From a total of 398 carcasses examined, 40 carcasses were positive for Campylobactcr with contamination rate of 10%. Per species contamination rate with either C. jejzmi or C. coli were 10.6% (n=218) and 9.4% (n=180) for sheep and goat carcasses respectively. However, statistically significant difference was not detected in the rate of carcass contamination between sheep and goat carcasses (p=0.72). The most prevalent thermophilic .C ampylob(lcter species recovered from the sheep and goat carcasses was C. jejl/Ili accounting for 7.3% (n=398), followed by C. coli 2.7% (n= 398). Out of the 40 positive samples the proportion of the C~pylobacter species was 72.5% and 27.5% for C. jejl/Ill and C. coli respectively. This variation in the isolation rate between the two Campylobacter species was slutistically significant (P:=O.003). Though there was no statistically significant difTcrence (1'=0.57) in the rate of carcass contamination among the four swabbing sites, the highest contamination rate was observed in the breast area at a rate of 12.6% (n=103) followed by abdomen with contamination rate of 11.6% (n=95). Hilihest rate of carcass contamination was observed after evisceration as compared to prior evisceration and after washing (p=O.OOO). Washing of the carcass did not reduce carcasscontmnination in the slaughtered shcep (x,2=O. 18; P=O.68). however there was n substantial reduction in the level of curcuss contllJlli.mtiulI uOcr wushing in gmit e .. reusses «x,2;,;; 10.72: P=O.OOI). 'Ine present study revealed the existence of severe cross contuminutiun during shlllghier operations particularly during evisceration. Carcass contamination by Campylobacter can be reduced, and thus its public health impact, through good hygienic practices in the ub.lltoir. Keywords: Abattoir, C.jejrmi, C. coli, Debre-Zeit, Ethiopia, sheep and goat carcass. x
Studies on Prevalence, Economic and Public Health Importance of Hydatidosis in Slaughtered Animals at Addis Ababa Abattoir, Ethiopia
(Addis Ababa University, 2008-06) Erbeto, Kebebe; Zewde, Girma
A cross sectional survey was conducted from November 2007 to April 2008 with the objective to determine the prevalence of hydatidosis in food animals slaughtered at Addis Ababa Abattoir, study the effect of risk factors on the prevalence of hydatidosis, evaluate the size, fertility and viability of the cysts, assess the economic losses and the public health significance of the disease. Routine meat inspection procedures was· conducted whereby livers, lungs, hearts, kidneys and spleens were visualized, palpated and incised to detect the presence of the cysts. The sizes of the cysts was determined by measuring the diameter in cm. Fertility was evaluated by observing the presence of protoscoleces under the microscope and viability was determined by staining the protoscoleces with 0.1 % aqueous solution of eosin. Protoscoleces which took up the stain were considered as non viable. The annual economic loss was calculated by multiplying the number of annually condemned organs with the current market value of organs . The public health significance was assessed by employing structured questionnaire. Out of the total of 3430 cattle, sheep, goats and pigs slaughtered and inspected at Addis Ababa Abattoir during the study period, 639 (18.6 %) of them were found to be infected with hydatidosis. Prevalence of254 (21 %),206 (19.9 %),102 (16 %) and 77 (14 %) were recorded in cattle, sheep, goats and pigs, respectively. Prevalence of 132 (20.9 %),85 (22.4 %) and 37 (18.7 %) was registered in cattle of Borana, Arsi and Abyssinian Zebu breeds, respectively. There was no significant variation in cattle of different breeds. Even though higher prevalence was detected in cattle from midland areas 124 (21.3 %) than in cattle originated from lowland areas 130 (20.5 %), there was no significant difference in prevalence in cattle from the two origins. The prevalence in cattle above 6 years old 117 was higher (95.9 %) than in cattle less than 2- 4 years old 11 (2.6 %). Prevalence of 88 (8.5 %),53 (5.1 %) and 65 (6.3 %) was recorded in Black Head - Ogaden, Adal and Abyssinian sheep breeds, respectively. Sheep under less than 1 year 77 (7.4 %) was more infected than sheep above 3 years of age 11 (1.1 %) and the difference in prevalence was significant. The prevalence of hydatidosis in ArsiBale and Keffa goat breeds was 53 (8.3 %) and 49 (7.6 %), respectively. The frequency of infection rate was higher in pigs kept at backyard 55 (10 %) than those managed under intensive husbandry system 22 (4 %). Out of the total 2071 cysts isolated from the different organs of cattle, 1007 (48.6 %) were small, 711 (34.3 %) medium and 353 (17 %) were large. VIIi More cysts were counted in the lungs of cattle, sheep and goats, but more cysts were found in swine's liver than in lung. Out of the total of 396 cysts isolated from organs of cattle, 217 (54.8 %) were fertile, 133 (33.6 %) sterile and 46 (11.6 %) were calcified. Out of the 217 fertile cysts, 185 (85.3 %) were viable and 32 (17.3 %) were none viable. The annual economic loss was estimated to be 10,923,601.00 Ethiopian Birr, which is equivalent to 1,139,061.63 USD. 234 cases of human hydatidosis were surgically treated at the Tikur Anbassa Referral Hospital in Addis Ababa. The economic and public health significance of the disease is discussed and pertinent conclusions are drawn.
STUDY ON THE EFFECT OF ACETIC ACID SPRAY ON ESCHERICHIA COLI LOAD AND MEAT QUALITY AT AN EXPORT ABATTOIR, MODJO, ETHIOPIA
(2012-06) AMSALU, WUDIE; Dr. Girma Zewde
The study was conducted to determine the effect of acetic acid (2.5%) spray on E. coli load in goat carcasses slaughtered in an export abattoir in Modjo, Ethiopia. A total of 144 swabbed samples were taken from 24 carcasses. Forty eight swabs were taken from front leg and hind leg areas before acetic acid spray, immediately after spray and after 24 hrs of chilling at 2±1oC. Following incubation of the samples at 37 oC for 48 hrs, loads of E. coli was visually counted in CFU/cm2. A portable hand pH meter was used to measure pH of carcass at 15 minutes after slaughter and at 24 hrs chilling at 2±1°C. Color changes of acetic acid sprayed carcass were monitored subjectively after 24 hrs of chilling at 2±1°C. The log mean of E. coli count before acetic acids spray, immediately after spray and after chilling were 2.53log10 CUF/cm2, 1.35log10 CUF/cm2 and 1.97log10CUF/cm2, respectively. The number of E. coli counts before acetic acid spray was higher in samples from front leg than hind leg area. Paired t-test comparison for means of E. coli counts before and after acetic acid spray showed significant difference (p<0.05). The log mean of E. coli counts for sprayed and chilled carcasses were higher when compared with sprayed carcasses; this variation was statistically significant (P< 0.05). Relatively lower pH were measured in sprayed chilled carcasses (with mean pH=5.77) than non-sprayed chilled carcasses (Mean pH=5.98). Mean pH of for non-sprayed chilled carcass and sprayed chilled carcasses were compared using a paired t-test; statistically, the result were significantly different (p<0.05). Goat carcasses after spray and chilling showed less darkness this was not appreciable in magnitude. It could be suggested that 2.5 % acetic acid spray with written sanitation standard operating procedures, with implementation of food safety management systems/hazard analysis and critical control points, reduce E.coli load, lowers the pH and reduces the darkness of carcasses.
RISK ASSESSMENTS OF PRIORITIZED TRANSBOUNDARY DISEASES IN BORENA BULLS MARKET CHAIN AND ITS IMPLICATION FOR INTERNATIONAL TRADE
(2012-06) GEZAHEGN, ALEMAYEHU; Dr. Girma Zewde, Dr. Brehanu Admassu
Risks of introduction of transboundary animal diseases (TADs) such as foot and mouth disease (FMD), lumpy skin disease (LSD) and contagious bovine pleuropnumonia (CBPP) through traded Borena bulls to market chain and its consequences were assessed. The assessment used the framework that has been recommended by the World Animal Health Organization (OIE) for risk analysis. Likelihoods for release and exposure were estimated by a qualitative scale ranging from negligible to very high. Whereas, the consequences resulted from diseases occurrences were assessed quantitatively. Fattened bulls intended to export originated mainly from Borena pastoral system where these transboundary animal diseases were endemically established. The likelihood of the introduction of TADs to the market chain through traded Borena bulls is found to be high for FMD and LSD and medium for CBPP. The probability of bulls in the feedlots becoming exposed to FMD virus and Mycoplasma mycoides subsp. mycoides small-colony type (MmmSC) bacteria is also high and very high for LSD virus. Biological consequence such as prevalence and incidence and economic loss were assessed. From the total of 11189 bulls observed during outbreak investigation of LSD in six sites of feedlot operation in and around Adama, 681(6.1%) and 204(1.8%) bulls were found affected and dead with LSD, respectively. From the total of 38187 bulls examined for FMD and CBPP antibodies, 5536(14.5%) and 150(0.4%) were found positive and subsequently rejected from international market in 2011, respectively. The total annual (2011) economic loss due to prioritized TADs was estimated to be 4,081,972.2 USD which is equivalent to 69,230,245.12 ETB (1USD= 16.96 ETB). The analysis of matrix scoring showed strong agreement (W=0.837 to 0.989; P=0.000) among the 10 informant groups for the disease indicators. The introduction of those diseases to the market chain of Borena bull for export is discussed in terms of international markets and trade disruptions. The risk estimates for all prioritized transboundary diseases are greater than negligible, therefore, transboundary diseases prevention strategy along the chain should be carefully considered by the Ethiopian veterinary services.

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