No abstract

Brucellosis is a zoonotic disease with economic and public health impact, particularly for human and animal populations within developing countries that relay on livestock production. A cross sectional study was conducted between October 2013 and March 2014 in and around Alage district to determine the seroprevalence of bovine brucellosis and associated risk factors. A total of 804 sera samples; 421 from cattle managed under extensive production system and 383 from cattle managed under intensive production system were collected. Multistage cluster sampling method was employed to sample unvaccinated cattle above 6 months of age. Rose Bengal Plate Test and c-ELISA were used in serial for detection of antibodies against Brucella species. The overall seroprevalence was 2.4 %, and herd level seroprevalence was 45.9 %. A prevalence of 3.3 and 1.3 % was recorded in the extensive and intensive farms respectively. Among the three sites, seropositivity of 3.4 % in Naka, 3.3 % in Negelewudisha and 1.3 % in Alage were recorded. Risk factors such as age, sex, number of service per conception, calving interval and reproductive status were associated with serostatus of brucellosis. Taken as a whole, cattle in both intensive and extensive production systems are endemically infected by brucellosis at low level in the study areas. This warrants the need of integrated intervention strategies to minimize the spread of the disease in animals and reduce the risk of transmission to humans.

Peste des petits ruminant (PPR) is an economically important disease of small ruminants with a rapidly expanding geographical distribution. There are fragmented reports to the occurrence and distribution of the disease in Ethiopia. A total of 700 serum samples were collected from goats and sheep to detect the presence of antibody against PPR virus using Competitive Enzyme-Linked Immunosorbent Assay (C-ELISA). An overall PPR seropositivity was reported to be 48.43% in the area. There is no statistically significant difference in the seroprevalence of the disease between sheep and goats (50.85% and 46.68%), respectively. However, there was statistically significant variation (P < 0.05) in the seroprevalence of the disease in young (33.9%) and adult (55.8%) age categories. The seroprevalence in male and female was 42.07% and 50.09%, respectively, where the variation was statistically not significant (P > 0.05). High seroprevalence of Peste des petites ruminants in the study area indicated the virus circulation and endemicity of the disease. The disease causes substantial economic losses by affecting the livelihood of the farmers. Therefore, control measures should be put in place to minimize the loss associated with the disease.

A total of 332 dairy cow's sera samples were collected from Kombolcha and Dessie districts of North Ethiopia to determine the sero-prevalence of infectious bovine rhinotracheitis (IBR), and Brucellosis. Sera samples were split into equal portions and competitive ELISA was used for testing IBR in the first portion while Rose Bengal test (RBT) and Complement Fixation Test (CFT) were used for detection of Brucellosis in the second portion. Sero-positivity was 25.6% (85/332) for IBR and 5.4% (18/332) for brucellosis with RBT which was found to be 0 (0%) by CFT. The prevalence of IBR was significantly influenced (P<0.001; OR=2.880) by parity with higher occurrence in multiparous compared to primiparous cows. IBR sero-positivity was highly associated (P<0.001) with repeat breeding, abortion and retained fetal membrane at odds ratio (OR) 8.833; 13.913 and 12.770, respectively. Similarly, IBR sero-positive animals had significantly higher (P=0.001) average days open, number of service per conception and calving interval than sero-negative animals. Conception rate at first service was higher (P<0.05, 74.4%) in sero-negative cows than in sero-positive dairy cows (25.6%). As latent infections and venereal transmissions are very common in IBR, its impact on the newly emerging urban dairy system would be significant unless an urgent control mechanism is designed. The associations of these reproductive infections with repeat breeding implies that they can seriously undermine the effort toward breed improvement in Ethiopia. Further studies with more detailed evaluation into various reproductive performance parameters should be the next step.

The Ethiopian government has several initiatives to expand and intensify the dairy industry; however, the risk of bovine tuberculosis (bTB) spread is a challenge. To assess the rate of expansion and risk factors for transmission of bTB within-herds, we carried out a repeated cross-sectional survey at two time points, 2016/17 and 2018, in three regional cities, namely, Gondar, Hawassa and Mekelle, representing the emerging dairy belts of Ethiopia. The total number of herds involved was 128, comprising an average of 2303 cattle in each round. The Single Intradermal Comparative Cervical Tuberculin (SICCT) test was used to identify reactor status and data on herd-level risk factors were collected using a structured questionnaire. In the first survey, the apparent prevalence of bTB, as measured by the SICCT test, was 4.5% (95% CI 3.7–5.4%) at the individual animal-level and 24% (95% CI 17.5–32%) at the herd-level. There was no statistically significant change in the overall apparent prevalence or regional distribution at the second survey, consistent with the infection being endemic. The incidence rate was estimated at 3.6 (95% CI 2.8–4.5) and 6.6 (95% CI 3.0–12.6) cases/100 cattle (or herd)-years at the animal- and herd-levels, respectively. Risk factors significantly associated with the within-herd transmission of bTB were age group and within-herd apparent prevalence at the start of the observation period. We noted that farmers voluntarily took steps to remove reactor cattle from their herds as a consequence of the information shared after the first survey. Removal of reactors between surveys was associated with a reduced risk of transmission within these herds. However, with no regulatory barriers to the sale of reactor animals, such actions could potentially lead to further spread between herds. We therefore advocate the importance of setting up regulations and then establishing a systematic bTB surveillance programme to monitor the impact prior to implementing any control measures in Ethiopia.