6 Variables Districts Chifra Dubti Afambo Amibara Herd size ≤25 11 < X ≤ 50 >50 Production system Agropastoral Pastoral CI: conﬁdence interval. 18 13 6 66 52 34 17 8 95 10 (55.6) 9 (69.2) 2 (33.3) 27 (40.9) 19 (36.5) 19 (55.9) 10 (58.8) 3 (37.5) 45 (47.4) Table 3: Multivariable logistic regression analysis of herd TB positivity with selected risk factors at ≥2 mm cut-oﬀ point. Number of herds examined Number of positive herds (%) Crude odds ratio (95% CI) Adjusted odds ratio (95% CI) Veterinary Medicine International 1.8 (0.40–8.07) 0.40 (0.06–2.77) 0.55 (0.19–1.58) 2.2 (0.91–5.31) 2.48 (0.81–7.59) 1 1 1 2.59 (0.49–13.73) 2.70 (0.06–114.64) 0.45 (0.14–1.39) 3.23 (1.21–8.60) 2.48 (0.76–8.09) 1 1 1 1.5 (0.34–6.64) 6.88 (0.28–170.32) a potential factor for transmission from human patient to animals. Previous studies in cattle of Ethiopia demonstrated that Mycobacterium tuberculosis was commonly isolated from tuberculous lesions of cattle in diﬀerent regions of Ethiopia [38, 39]. In sheep, we observed 1.44% prevalence of TB at 2 mm cut-oﬀ point and no at 4 mm cut-oﬀ point. The result was in agreement with previous studies where sheep TB has been reported both with tuberculin skin test and postmortem examination results [3, 4, 9, 10, 12, 16]. In conclusion, this study revealed a moderately low prevalence of TB in goats and sheep of Afar Pastoral Region of Ethiopia. Mycobacterium tuberculosis and nontuberculosis mycobacteria were isolated as causative agents of TB in goats of the region. The isolation of the Mycobacterium tuberculosis in goat indicates the need for further studies to understand the interspecies transmission dynamics of Mycobacterium tuberculosis and the role of small ruminants in the epidemi- ology of human tuberculosis in pastoralist setting where potential epidemiological risk factors for infection and transmission between livestock and human exist. In addition, the identiﬁcation of nontuberculosis mycobacteria from tuberculous lesions in goats indicates their importance in the epidemiology of small ruminant TB and further research is needed to identify the species and their public health signiﬁcance for the pastoralist communities of the region. In general, similar to the previous studies carried out in cattle and camel of pastoral regions of Ethiopia [18, 20–22, 36] which have indicated the endemic nature of tuberculosis in these species, the result of this study also indicated the impor- tance of tuberculosis in small ruminants of Afar Pastoral Region which further emphasizes the need to design a fea- sible national TB control strategy in livestock of the country. Authors’ Contribution G. M. Kassa contributed to the design of the study, par- ticipated in collection, analysis, and interpretation of data, drafted and revised the paper. F. Abebe contributed to the design of the study, interpretation of data, and critically Figure 1: Tuberculous lesion from goat lung caused by Mycobac- terium tuberculosis. the other districts, which can favor a potential transmission of mycobacterial species between cattle and goat. Older goat and sheep showed higher proportion of positivity in tuberculin test results which might be related to the fact that older animals have longer duration and repeated chance of exposure to mycobacterial infection with their age. Similar results have been reported by other researchers in cattle [34, 35]. Female animals with more parity number showed higher proportion of positivity in tuberculin test results than in those with lower parity number. This might be related to the age of the animals as animals with high parity number were older in their age which increases their chance of exposure to mycobacterial infection in their longer life time. Mycobacteriological culture of the tissue lesions from the ﬁve tuberculin reactors goats had resulted in the isolation of Mycobacterium tuberculosis and nontuberculosis mycobacte- ria species. In this study, Mycobacterium tuberculosis strain SIT149 was isolated from a goat suggesting the possibility of its transmission from human to goat. Similar strain has been isolated in camel from pastoral region in south east of Ethiopia [36]. The SIT149 strain of Mycobacterium tuberculosis is a dominant strain in Ethiopia [37], and it was a common isolate in human pulmonary TB patients from the same Afar Pastoral Region indicating that the isolate has been circulating in the area. Afar pastoralists have close contact with goats and sheep and often keep young goats and sheep in their house at night which might be