Rahmeto Abebe

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.

Fasciolosis: Prevalence, financial losses due to liver condemnation and evaluation of a simple sedimentation diagnostic technique in cattle slaughtered at Hawassa Municipal abattoir, southern Ethiopia

An abattoir survey was carried out in Mekelle municipal abattoir, Ethiopia to determine the prevalence of concurrent infections of hydatidosis and fasciolosis in cattle. A total of 4,481 slaughtered cattle were studied by ante- and post-mortem examinations. From the total 4,481 slaughtered cattle examined at Mekelle municipality abattoir, 357 (8%) were found to harbor mixed infection of hydatidosis and fasciolosis. While the individual prevalence of hydatidosis and fasciolosis was 32.11% and 24.32%, respectively. Multivariate logistic regression analysis indicated that among the factors considered in the current study, origin of animals had statistically significant ffect on the prevalence of concurrent infection (OR = 1.418, 95% CI = 1.108 - 1.814, p = 0.005), whereas breed and body condition of animals didn’t have significant effect on prevalence of the co-infection. Moreover, month had no statistically significant effect on prevalence of hydatidosis and fasciolosis co-infection (OR= 1.0029, 95% CI = 0.9758 - 1.0306, p = 0.867). Generally this study showed that hydatidosis and fasciolosis are important disease problems in cattle in the study area. The relatively higher prevalence in the occurrence of the concurrent infection of hydatidosis and fasciolosis in this study may suggest that ecological factors that determine the occurrence of the two diseases might be similar. On the other hand, the higher prevalence of the individual or concurrent infection may imply that these diseases have the potential to cause considerable economic and public health problems. Keywords: Coinfection, Fasciolosis, Hydatidosis, Mekelle, Prevalence.

Lungworm infection in small ruminants: Prevalence and associated risk factors in Dessie and Kombolcha districts, northeastern Ethiopia

A cross-sectional study was conducted from November 2008 to March 2009 to estimate the prevalence of lungworm infection and to investigate some of the risk factors associated with small ruminant lungworm infections in Dessie and Kombolcha districts, northeastern Ethiopia. Faecal samples were collected from randomly selected 404 animals (240 sheep and 164 goats) to examine first stage larvae (L(1)) using modified Baerman technique. One hundred and thirty eight animals (113 sheep and 25 goats) were also subjected to postmortem examination to detect the presence of adult lungworm parasites. The overall prevalence recorded by faecal and postmortem examinations were 36.9% and 62.3%, respectively. Prevalence of lungworm infection was significantly higher (OR=2.1, 95% CI=1.2, 3.5) in sheep (40.4%) than in goats (31.7%). The proportions of infection by Dictyocaulus filaria (D. filaria), Mullerius capillaris (M. capillaris) and mixed infection were 1.3% (3/240), 28.3% (68/240) and 10.8% (26/240) in sheep; and 20.1% (33/164) by M. capillaris and 11.6% (19/164) with mixed infection in goats. Animals above one year (OR=8.7, 95% CI=4.8, 15.6), non-dewormed animals (OR=10.4, 95% CI=5.6, 19.3) and those sampled during November (OR=3.6, 95% CI=1.5, 8.6) had higher odds of infection prevalence than animals in corresponding groups. The mean count of L(1) larvae of D. filaria and M. capillaris were 5.4 (95% CI=3.6, 7.3) and 39.3 (95% CI=33.7, 44.9) in ovine and 4.5 (95% CI=3.1, 5.8) and 34.1 (95% CI=27.2, 41.1) in caprine, respectively. The recorded average larval count of the two parasitic species varied significantly in both sheep and goats. This study showed high prevalence of lungworm infections which impairs the productivity of small ruminants, implying the need for control intervention.

Bovine mastitis: prevalence, risk factors and isolation of Staphylococcus aureus in dairy herds at Hawassa milk shed, South Ethiopia

BackgroundMastitis is a disease of major economic importance in dairy industry worldwide. It is of particular concern in developing countries like Ethiopia, where milk and milk products are scarce. The objectives of the study were to estimate the prevalence of mastitis, identify the cow-and herd-level potential risk factors and isolate Staphylococcus aureus, one of etiological agents for contagious mastitis, from cows positive for mastitis. A total of 529 lactating cows selected randomly from 95 herds were screened by California mastitis test (CMT) for sub-clinical mastitis. Also 172 milk samples collected from CMT positive cows were cultured for isolation of S. aureus.ResultsBased on CMT result and clinical examination, the prevalence of mastitis at herd-level was 74.7% (95% CI: 64.5, 82.8). The corresponding cow-level prevalence was 62.6% (95% CI: 58.3, 66.7), of which 59.2 and 3.4% were sub-clinical and clinical mastitis cases, respectively. S. aureus was isolated from 51.2% of the milk samples cultured and 73.2% of the herds affected with mastitis. In the multivariable logistic regression model, the herd-level factors significantly associated (p < 0.05) with the presence of mastitis were herd size, bedding material, and milking mastitic cows last, while at cow-level, breed, parity, stage of lactation, udder and leg hygiene, and teat end shape were noted to have a significant effect on mastitis occurrence.ConclusionThe very high prevalence of mastitis, more importantly the sub-clinical one, in the herds examined revealed the huge potential economic loss the sector suffers. Perhaps this was attributed to lack of implementation of the routine mastitis prevention and control practices by all of the herd owners. The findings of this study warrants the need for strategic approach including dairy extension that focus on enhancing dairy farmers’ awareness and practice of hygienic milking, regular screening for sub-clinical mastitis, dry cow therapy and culling of chronically infected cows.

Prevalence of haemoparasites and associated risk factors in working donkeys in Adigudem and Kwiha districts of Tigray region, Northern Ethiopia

A cross-sectional study was conducted from November 2008 to March 2009 in Adigudem and Kwiha districts of Tigray regional state with the objective of identifying the prevalence of haemoparasites and the associated risk factors in working donkeys. Blood samples were collected from a total of 400 randomly selected donkeys and examined by dark ground/phase contrast buffy coat technique and Giemsa stained blood smears. The overall prevalence of haemoparasites was 2.5% (n =10) without significant variation between the two districts (p>0.05). Babesia and trypansomes were the haemoparasites observed in the donkeys with a prevalence of 1.75% (n=7) and 0.75 % (n=3), respectively. Species identification has indicated the presence of two species of Babesia: Babesia equi (71.43%) and Babesia caballi (28.6%) whereas all the trypanosomes encountered belong to the single species of Trypanosoma vivax. No significant association was observed between the prevalence of either of the two haemoparasites and the hypothesized risk factors (district, sex, age and body condition score) (p>0.05 for all factors). The mean packed cell volume (PCV) of trypanosome infected donkeys (20.67±4.04) was significantly (p 0.05). Moreover, this study has shown that 22% donkeys tested serologically were seropositive for Trypanosoma evansi and Trypanosoma equiperdum. Overall, the prevalence of haemoparasites reported in the current study is low compared with previous studies and might be associated with the study design, the season of study, low sensitivity of the parasitological technique or a better veterinary service provided in the area by a charity organization.

A cross-sectional study of trypanosomosis and its vectors in donkeys and mules in Northwest Ethiopia

A preliminary study was conducted in January 2009 in four peasant associations (PAs) selected from two districts in Benishangul Gumuz Regional State, Northwest Ethiopia to investigate the prevalence and species of trypanosomes infecting donkeys and mules and identify the fly vectors playing a role in the transmission of trypanosomosis. Blood samples were collected from a total of 334 donkeys and 52 mules and examined by dark ground/phase contrast buffy coat technique and Giemsa-stained blood smears. Accordingly, trypanosome species were encountered in 6.3% of the examined donkeys (n = 21) while none of the mules examined was positive for trypanosome infection. Trypanosomes and tsetse flies were detected in two of the four PAs surveyed (Tsetsa adurno and Bamadone) with significant (P = 0.004) difference in prevalence. The inability to find trypanosomes in the other two PAs (Ura and Ashura) was most likely due to the absence of appropriate fly vectors. Three species of trypanosomes were detected in donkeys, which in order of predominance were Trypanosoma congolense (52.4%), Trypanosoma brucei (28.6%), and Trypanosoma vivax (19.05%). There was a significant (P = 0.008) difference in mean PCV between trypanosome infected and non-infected donkeys. The body condition score of the donkeys was significantly associated with both prevalence of infection (P = 0.009) and mean packed cell volume (PCV; P < 0.0001). No significant difference was observed between male and female donkeys regarding both prevalence of infection and mean PCV (P > 0.05 for each factor). The entomological surveys revealed the presence of Glossina morsitans submorsitans and other biting flies of the family Stomoxys, Tabanus, and Haematopota. In conclusion, the prevalence of trypanosomosis obtained in the current study is generally low compared to previous studies. As the present study design was a cross-sectional, one that only depicts a momentary picture of the infection status in the herd, a further longitudinal study that makes use of more sensitive techniques and entomological survey is recommended.

Mange mite infestation in small ruminants in Ethiopia: Systematic review and meta-analysis.

Mange mites are economically important ectoparasites of sheep and goats responsible for rejection or downgrading of skins in tanneries or leather industries in Ethiopia. The objective of this systematic review was to compute the pooled prevalence estimate and identify factors influencing mange mite prevalence in sheep and goats at national level based on the available research evidence. Articles on mange mite infestation of small ruminants in Ethiopia were searched in PubMed, Web of Science, Google scholar and African journals on-line. The review was based on 18 cross-sectional studies carried out between 2003 and 2015 in four administrative states of Ethiopia. Accordingly, the pooled prevalence estimate in a random effects meta-analysis was estimated to be 4.4% (95% CI 3.0, 6.3) although there were evidence of a substantial amount of between-study variance (I(2)=98.4%). In subgroup and multivariable meta-regression analyses, animal species, agro-ecology and administrative state were found to have significant effect on the prevalence estimate (P<0.05) and explained 32.87% of the explainable proportion of the heterogeneity noted between studies The prevalence was found to be higher in goats in lowland agro-ecology. Region wise the highest estimate was calculated for Amhara (6.4%) followed by Oromia (4.7%), Tigray (3.6%) and Southern Nations, Nationalities and People Region (SNNPR) (3.1%). Significant difference was noted between Amhara and SNNPR. The study further revealed that mites of the genus Sarcoptes, Demodex and Psoroptes are the most prevalent mites infesting small ruminants in Ethiopia. Valid studies were lacking from five regional states. As some of these regions are known for their large small ruminant population, further studies are warranted to produce better picture of the infestation at a national level. Meanwhile, the need for monitoring the ongoing control intervention is suggested.

Lungworm infection in small ruminants in and around Wolaita Soddo town, Southern Ethiopia.

This study was conducted between November 2010 to April 2011 to estimate the prevalence of lungworm infection in small ruminants, determine the parasite species and identify the potential risk factors in and around Wolaita Soddo town, Southern Ethiopia. Faecal samples were collected from 360 randomly selected small ruminants (204 sheep and 156 goats) and processed with the modified Baerman technique for the extraction of first stage larvae. Overall, 45 (22.1%) sheep and 30 (19.2%) goats were found infected with lungworms. No significant difference was observed in the prevalence of lungworm infection between sheep and goats (p>0.05). Dictyocaulus filaria was the single lungworm species identified in both sheep and goats. The risk factors analyzed were sex, age, management system (zero-grazing or free-ranging), deworming history and body condition score (BCS). Management system, deworming history and BCS were significantly associated with the prevalence of D. filaria infection in sheep and goats (p 0.05). In conclusion, the association of lungworm infections with the management system and deworming status of the animals in the present study are as expected. The association of infection with BCS requires further research to investigate if improving the nutritional status, thereby improving BCS, will result in lower prevalence of lungworm infection. Also, as the present sample size is thought to be small, further study with a larger sample size is required to determine the effect of age and host species difference in susceptibility to lungworm infection. One of the limitations of this study is that it is a one season survey and thus, a further year-round investigation is warranted to establish the association between seasonal variation and infection.

Prevalence of Epizootic Lymphangitis and Bodily Distribution of Lesions in Cart-Mules in Bahir Dar Town, Northwest Ethiopia

Epizootic lymphangitis (EL) is a debilitating equine disease that in its classical form is characterized by chronic discharging cutaneous nodules. The disease has been reported to be endemic in Ethiopia, a country where equids provide a vital utility and source of income to many people in resource-poor settings. This study was conducted in Bahir Dar town, Northwest Ethiopia to investigate the prevalence, risk factors and bodily distribution of lesions of EL in cart-mules. To this effect, both clinical and microscopic examinations were made on a total of 402 mules and an overall prevalence of 32.84% (132/402) was recorded. The mules had nodular, ulcerative pyogranulomatous lesions following the lymphatic lines of the legs (79.6%), on their neck (9.85%), around the inguinal area (6.82%), on their back (2.27%) and on their perineum (1.52%). None of the risk factors considered (sex, body condition score, use of harness, and presence of wound prior to the disease) were noted to be significantly associated with the presence of EL on mules (p>0.05). Moreover, 34% of the cart-mule owners were reported not to allow mules affected with EL offwork even for a single day. In conclusion, the present study has revealed a high prevalence of EL in mules and it is the second work in Ethiopia disproving the assumption that mules are resistant to the disease. Thus, early detection of the disease and treatment with effective drugs and restriction of movement of affected animals is recommended to prevent the spread of the disease to unaffected equids. Also, future studies are required to find out the factors predisposing mules to EL.

Bovine trypanosomosis and vector density in Omo-Ghibe tsetse belt, South Ethiopia

African animal trypanosomosis (AAT) is a parasitic disease that causes serious economic losses in livestock from anemia, loss of condition, emaciation and death in untreated cases. It is one of the major constraints to improved livestock production and productivity in Ethiopia. Entomological and parasitological surveys were conducted in the Omo-Ghibe tsetse belt of south Ethiopia to estimate the prevalence of bovine trypanosomosis and the apparent tsetse density (AD), and identify the potential risk factors. For the parasitological study, blood samples were collected from 1508 cattle sampled from 11 districts and assayed using the buffy coat technique and Giemsa-stained thin smears. For the entomological survey, a total of 216 biconical and NGU traps were deployed in all districts. The overall animal-level prevalence of trypanosomosis was 7.8% (95% CI: 6.5, 9.3). The trypanosome species identified were Trypanosoma congolense (75.4%), T. vivax (20.3%), T. brucei brucei (1.7%) and mixed T. congolense/T. vivax (2.6%). Regarding the entomological survey result, a total of 2243 tsetse flies were captured which identified to be Glossina pallidipes (85.1%) and G. f. fuscipes (14.9%). Besides, other biting flies of the genus Stomoxys (n=146) and Tabanus (n=17) were also trapped. The AD noted in the present study was 3.5 flies/trap/day. Both the prevalence of trypanosomosis and AD of tsetse flies were significantly (p<0.05) influenced by altitude. The prevalence of trypanosomosis was also significantly (p<0.05) associated with poor body condition score, black coat color and lower mean packed cell volume while no significant prevalence difference was noted along with age and sex category. In conclusion, the present study suggested that trypanosomosis is an important disease of cattle in the Omo-Ghibe tsetse belt in dry season. The disease is mainly caused by the most pathogenic T. congolense and transmission is predominantly by tsetse flies, particularly G. pallidipes. The study warrants the need for strengthening the vector and parasite control interventions in the area.