Systematic review and meta-analysis of metacestodes prevalence in small ruminants in Ethiopia.

Metacestodes, the larval stages of canid cestode parasites, are among the causes of morbidity, mortality and financial losses in small ruminants in Ethiopia as a result of organ and carcass condemnation at slaughter. Several studies have been conducted over the years; however, these studies often had limited scope and coverage. This systematic review and meta-analysis was conducted to collate the information so far available in order to provide a pooled prevalence estimate at national level and identify potential predictors. Published and grey literature written in English and Amharic in the period from, 1st of January 1990 to June 25, 2015 were searched from electronic databases and repositories of academic and research institutions. Relevant animal level data on 67,743 small ruminants was extracted from 23 published articles and one master's thesis resulting altogether in 86 animal level reports that conformed to predefined criteria. The dataset was analyzed using a meta-analytical approach. The pooled prevalence estimate computed for metacestodes infection was 11.8% with a 95% confidence interval (CI) of 9.1, 15.4. The highest prevalence estimate 31.2% (95% CI: 23.1, 40.9) was found for Cysticercus tenuicollis (Taenia hydatigena) followed by cystic echinococcosis (Echinococcus granulosus) 8.8% (95% CI: 5.8, 13.1), Cysticercus ovis (Taenia ovis) 4.9% (95% CI: 2.9, 9.4) and Coenurus cerebralis (Taenia multiceps) 4.6% (95% CI: 1.6, 12.2). Among the predictors considered for heterogeneity analysis only sample size and metacestode type fitted the final multivariable meta-regression model and explained 26.3% of the explainable heterogeneity between studies (p<0.05). The prevalence was noted to decrease with increasing sample size. No significant difference in prevalence was observed between sheep and goats (p>0.05). In conclusion, this review showed a widespread occurrence of metacestodes in small ruminants in Ethiopia. Thus, a holistic approach to break the life cycle of these parasitic stages is suggested, including regulatory interventions that encourage dog owners to keep their dogs confined and prevent backyard slaughter and proper management of abattoir waste disposal.

Bovine trypanosomosis and its fly vectors in three selected settlement areas of Hawa-Gelan district, western Ethiopia.

A cross-sectional study aimed at investigating the species diversity of fly vectors and estimating the prevalence of bovine trypanosomosis was carried out from October 2009 to May 2010 in selected settlement areas of the Hawa-Gelan district in the western Wollega zone of Ethiopia. Standard methods of sampling and identification were employed for both entomological and parasitological examination. Three species of the genus Glossina (Glossina pallidipes, Glossina morsitans submorsitans and Glossina fuscipes) and two genera of biting flies (Stomoxys and Tabanus) were caught and identified. The overall apparent density of Glossina species caught was 10.5 flies per trap per day, with a higher proportion of female flies (57.2%). Out of a total 389 cattle examined, 42 (10.8%; 95% CI: 7.89% - 14.3%) were found infected with trypanosomes. Three trypanosome species were detected in the study area, namely Trypanosoma congolense (54.8%), Trypanosoma brucei (23.8%) and Trypanosoma vivax (21.4%). The prevalence of trypanosomosis was found to be significantly (p < 0.05) higher in cattle with poor body condition. There was an association between mean packed cell volume (PCV) and the occurrence of parasitaemia (χ2 = 49.5, p < 0.05). About 95.2% of cattle that were positive for trypanosomes had a PCV less than the lower limit for cattle. Considering the current result, bovine trypanosomosis seems to be a serious constraint for agricultural activities in the settlement areas of the Hawa-Gelan district and seems to be associated with the presence of Glossina species. Therefore, application of control methods through community involvement to reduce the Glossina species infestation level is likely to increase animal productivity.

A study on seroprevalence of caprine brucellosis under three livestock production systems in southern and central Ethiopia.

Caprine brucellosis in Ethiopia is less commonly reported with limited information on the disease status in the country. The objective of this study was therefore to highlight the status of goat brucellosis in three distinctly different livestock production systems of southern and central Ethiopia. A total 3,315 goats of different age and sex, living with other animals in variable flock size, were sampled from 448 flocks raised in sedentary, pastoral and agro-pastoral production systems. Goats were bled aseptically and sera were collected for serial testing using Rose Bengal Plate Test as screening test and subsequently complement fixation test as confirmatory test. Questionnaire and laboratory data were analysed for descriptive, univariable and multivariable logistic regression analysis both at individual and flock level (STATA 11). The study revealed an overall animal level seroprevalence of 1.9 % (95 % CI 1.5, 2.4). In sedentary production system, the observed seroprevalence was 0.6 % (95 % CI 0.2, 0.9) while 1.9 % (95 % CI 1.1, 2.7) and 7.6 % (95 % CI 5.1, 10.1) were the proportion of seroreactors for agro-pastoral and pastoral production systems, respectively. The observed prevalence difference between the three production systems was statistically significant (P < 0.05). At the flock level analysis, 11.2 % (95 % CI 8.2, 14.1) of the flocks sampled had at least one seropositive goat among themselves. Like individual level analysis, the highest prevalence of 32.5 % (95 % CI 21.9, 43.0) was recorded for pastoral production system, followed by agro-pastoral, 13.0 % (95 % CI 7.0, 19.0) and sedentary production system, 3.6 % (95% CI 1.3, 6.0). Accordingly, the odds of Brucella seropositivity were higher (OR = 12.8) in pastoral followed by agro-pastoral (OR = 4.0) in relation to sedentary production system. Large numbers of seroreactors were observed in adult age living in larger flocks with other livestock species. However, no difference was noted between male and female goats. Finally, the need for nationwide survey and subsequent designing and implementation of appropriate control measure is suggested.

Anthelmintic utilisation practices and prevalence of gastrointestinal helminth infections in sheep kept in the urban and peri-urban areas of Bishoftu Town.

Assessment of the anthelmintic (AH) utilisation practices and estimation of the prevalence of gastrointestinal helminth infections in sheep were carried out from November 2010 to April 2011 in urban and peri-urban areas of Bishoftu Town, central Ethiopia. A structured questionnaire was employed to assess the AH utilisation practices in sheep of 310 owners/households, while floatation and sedimentation techniques were used to study the prevalence of helminth infections. Faecal examinations revealed that 53.9 % of sheep harboured gastrointestinal helminth infections with a high frequency due to strongyles (77.3 %). The questionnaire survey revealed that sources of AH for sheep were government and private veterinary clinics for 98.5 % of urban and 65.4 % peri-urban respondents. In peri-urban areas, AH were also purchased from open markets and illegal dealers. Albendazole was the most common (75.5 %) drug used in sheep followed by ivermectin (18.7 %) and tetramisole (5.8 %). The criteria for selecting AH were: prescription by veterinarians (51.6 %), efficacy (31.9 %), price (12.3 %) and arbitrary reasons (4.2 %). Treatment frequency was minimal with 51.3, 32.3 and 15.8 % of the owners treating their sheep once, twice and less than once per year, respectively. Treatments mainly depended on manifestations of general (45.8 %) and digestive (23.3 %) symptoms. Irrespective of the body weight of the sheep, albendazole was the only drug reported to be given at half bolus/sheep (14.1 %). Owing to this practice, albendazole faces the risk of reduced efficacy or AH resistance due to its wide spread utilisation, handling by untrained personnel and suspected underdosage, which altogether support the perception of sheep owners on its lower effect on the performance of treated sheep.

Occurrence and financial loss assessment of cystic echinococcosis (hydatidosis) in cattle slaughtered at Wolayita Sodo municipal abattoir, Southern Ethiopia.

A cross-sectional study aimed at determining the prevalence and cyst characteristics and estimating the financial loss due to cystic echinococcosis (hydatidosis) in cattle slaughtered at Wolayita Sodo municipal abattoir was conducted from November 2009 to April 2010. Out of 546 cattle examined, 92 (16.85%) were found to harbor visible hydatid cysts. Significantly higher infection was detected in local (P < 0.05) than crossbred cattle. No significant variation was observed with regard to origin, sex, and body condition status of animals. Regarding organ distribution, infections of the lung, liver, spleen, and kidney were 57.78%, 35.46%, 8.75%, and 4.01%, respectively. Of the total 1,097 hydatid cysts counted, 952 (86.78%), 136 (12.4%), and eight (0.82%) were found to be small-sized, medium-sized, and large-sized, respectively. Likewise, out of 450 cysts assessed, 138 (30.67%) were fertile, 241 (53.56%) sterile, and 71 (15.78%) calcified. Of the 138 fertile cysts subjected for viability test, 13 (9.42%) were viable while 125 (90.57%) were nonviable. Moreover, assessment of annual economic loss due to bovine hydatidosis at Wolayita Sodo municipal abattoir from offal condemnation and carcass weight loss was estimated at 410,755.90 Ethiopian Birr (ETB; 30,202.64 US$; 1 US$ = 13.60 ETB). Despite the moderate magnitude of infection detected currently, there seems to be an existing socioeconomic situation favorable for hydatidosis, and hence, it remains one of the most important diseases warranting serious attention for prevention and control actions in Wolayita zone. Hence, establishment of well-equipped standardized abattoirs, creation of public awareness, and control of stray dogs are of paramount importance.

Survey of ixodid ticks in domestic ruminants in Bedelle district, Southwestern Ethiopia.

A survey aimed at determining the status of ticks in cattle, sheep and goats in Bedelle district (Southwestern Ethiopia) was carried out from November 2007 to April 2008. Out of the total 330 animals examined, 314 (95.2%) were found to be infested (harbouring of at least a single tick). High rates of infestations were recorded across all three host species. Factors like month of collection, age and sex of host species did not show significant association with infestation rates. A total of 5,507 ticks belonging to three genera (i.e. Amblyomma, Boophilus and Rhipicephalus) were collected during the study period of which six species were identified. The species of ticks encountered comprise of Amblyomma cohaerens (44.1%), Amblyomma variegatum (13.8%), Amblyomma lepidum (1.2%), Boophilus decoloratus (24.9%), Rhipicephalus evertsi evertsi (14.3%) and Rhipicephalus lunulatus (1.7%). As about 86.7% (4,772) of the ticks were collected from cattle, it was recognised that this could be an evidence of host preference where cattle are serving as principal host while sheep and goats serve as alternative hosts. The role of ecological factors and little attention paid by livestock owners for treatment of animals against ticks are suggested to result in the abundance of ticks. Acaricide spraying should be strategically applied to control ticks. Better result could be achieved if an emphasis is being put on spraying cattle. Studies on tick-borne diseases, involvement of wildlife species as well as related factors are recommended as they may provide a valuable basis for designing and launching an all-round control programme in the country.

Evaluation of Deltamethrin applications in the control of tsetse and trypanosomosis in the southern rift valley areas of Ethiopia.

A study aimed at evaluating the efficacy of Deltamethrin (0.4% impregnated targets and 1% pour-on formulation) in controlling tsetse and trypanosomosis was carried out in two selected 10km x 10km Universal Transverse Mercator Grids of the Southern Tsetse Eradication Project (STEP) area in the southern rift valley of Ethiopia. The Grids selected were H3 (site I) and G5 (site II) in two districts of the Wolaita Zone. The trial was underway from September 2003 to April 2004. The strategy followed to accomplish the trial was a pre-intervention phase (entomology and parasitology) and an intervention phase with insecticide (Deltamethrin 0.4%)-impregnated odour-baited targets in site I and Deltamethrin 1% 'pour-on' application to cattle in site II. The intervention phase was monitored on a monthly basis. Following the deployment of 460 targets at a density of 4 targets per km(2) in trial site I, the relative abundance of tsetse fly (Glossina pallidipes) declined from a pre-intervention mean catch of 1.35 flies per trap per day to 0.05 flies per trap per day at final monitoring. These resulted in an 88.9% overall reduction. Similarly, an 83.25% reduction was recorded in the incidence of trypanosomosis in sentinel cattle as it dropped from 10.75% (first monitoring) to 1.8% (last monitoring). The corresponding measures of packed cell volume (PCV) have shown a significant improvement from a mean of 21.8% (95% confidence interval (CI): 20.7-22.9) at first monitoring to 25.5% (95% CI: 24.3-26.7) of last monitoring (P<0.01). In site II, the trial was started by spraying Deltamethrin 1% pour-on to 409 cattle at a rate of 1ml/10kg body weight. Pour-on treatment was repeated every month throughout the trial period. A sharp drop in the relative abundance of tsetse fly was revealed soon after. The catch was nil at fourth monitoring as it declined from 0.91 flies per trap per day of pre-intervention (P<0.01). A 94.9% overall reduction was achieved. The incidence of trypanosomosis in sentinel cattle also declined from 10% (first monitoring) to 0.95% (last monitoring) with about 90.5% decline. An improvement in the overall mean PCV was seen as it rose from a mean of 24.1% (95% CI: 22.9-25.3) at first monitoring to 27.2% (95% CI: 26.2-28.1) at last monitoring which revealed a significant increase (P<0.01) until the third monitoring and maintained a stable state thereafter. This work finally disclosed that a relatively better efficacy was attained by using Deltamethrin pour-on formulation than targets in controlling tsetse and trypanosomiosis. However, this difference did not prove an apparent significance (P>0.05). So it is recommended to continue the current tsetse suppression by using the integrated approach of both techniques under consideration.

Study on the prevalence of cystic hydatidosis and its economic significance in cattle slaughtered at Hawassa Municipal abattoir, Ethiopia.

A cross-sectional study was conducted from December 2008 to March 2009 to assess the status of cystic hydatidosis in cattle slaughtered at Hawassa Municipal abattoir. Out of the total 632 cattle examined visually and manually (palpation and incision), 333 (52.69%) were found harboring hydatid cysts. A significantly higher infection was detected in older cattle (P < 0.05, chi(2) = 4.36) than young. Regarding body condition score, no significant variation (P > 0.05, chi(2) = 2.148) was observed as the prevalence was 54.55% for lean cattle followed by medium (53.83%) and fat (46.88%). Of the total 333 infected, 123 (36.9%) had hydatid cysts only in the lung, 23 (6.9%) in the liver, 12 (3.6%) in the spleen, five (1.5%) in the heart, and three (0.9%) in the kidney while the rest 167 (50.2%) had multiple organ infections. Of the 530 viscera harboring hydatid cysts, the highest (52.83%) was lung followed by liver (34.15%), spleen (9.06%), heart (3.39%), and kidney (0.56%). Size assessment made on 874 cysts indicated that 308 (35.3%) were small, 251 (28.7%) medium, 89 (10.2%) large, and 226 (25.9%) were calcified. The distribution of characterized cysts in different organs based on their size was found to be statistically significant (P < 0.05). In addition, out of the total 874 cysts collected, 26.9% were fertile, 47.3% sterile, and 25.9% calcified or purulent cysts. There was a significant difference in fertility of cyst from different organs (P < 0.05, chi(2) = 27.96), those of lung origin being highly fertile. Likewise, out of the 121 fertile cysts subjected for viability test, 68 (56.2%) were viable. Considering the current result, the total annual economic loss from organ condemnation and carcass weight loss due to bovine hydatidosis at Hawassa Municipal abattoir was estimated at 1,791,625.89 Ethiopian Birr (ETB; 1USD = 12.93ETB). Results in the study were discussed in light of the situation in different parts of Ethiopia and abroad, and finally, relevant recommendations were forwarded.