Table_1_Serotyping and Seroprevalence of Mannheimia haemolytica, Pasteurella multocida, and Bibersteinia trehalosi and Assessment of Determinants of Ovine Pasteurellosis in West Amhara Sub-region, Ethiopia.DOCX

A cross-sectional study was undertaken in four (4) districts of the West Amhara sub-region of Ethiopia with the aim of assessing the diversity and distribution of serotypes of Pasteurella species, their seroprevalence, and associated risk factors, and knowledge, attitude, and practice of farmers toward ovine pasteurellosis. A total of 600 sheep sera were collected using multistage cluster sampling. Each sample was examined for the presence of six (6) serotype-specific antibodies using an indirect haemagglutination test. We are reporting a higher seroprevalence of 90.17% (541/600) in which all seropositive animals were shown to have been co-infected with multiple serotypes. Individual serotype prevalence showed that serotype A7 has the highest prevalence of 77.83% followed by A2 (74.33%), T15 (64%), T4 (62%), PA (60%), and A1 (39.17%). In this study, being female [odds ratio (OR): 2.45, 95% CI (1.09–5.52), p = 0.031] and living in high altitude areas [OR: 20.29, 95% CI (2.54–161.95), p = 0.004] were found to be significantly associated with sero-positivity. A questionnaire survey (n = 384) employed in a face-to-face interview was used to assess the knowledge, attitude, and practice of farmers related to ovine pasteurellosis. Accordingly, the majority (72.4%) of respondents had an inadequate knowledge level of the disease. The proportion of farmers with a favorable attitude and good practices toward the disease was 50.26 and 77.6%, respectively. This study is highly indicative that ovine pasteurellosis is a ubiquitous disease in the study area challenging the sheep production sector. The existence of diverse serotypes reported to lack cross-protective immunity is likely to explain why the current vaccination practice with the mono-serotype Pasteurella multocida biotype A vaccine is not providing adequate protection against outbreaks of the disease. Prioritization of one or more serotypes for inclusion in a multivalent vaccine should be dictated by the abundance and distribution of a particular serotype, its clinical importance, and its resultant economic impact. Furthermore, training farmers on key aspects of the disease is vital in the implementation of effective disease management strategies through a participatory approach. Data from the remaining regions of the country could help realize the development of an effective vaccine that works best at the national level.

本研究于埃塞俄比亚阿姆哈拉州西部片区的4个行政区开展横断面研究，旨在评估巴斯德菌属（Pasteurella）血清型的多样性与分布特征、血清阳性率及相关危险因素，同时调查养殖户对羊巴氏杆菌病的知识、态度与行为。研究采用多阶段整群抽样法，共采集600份绵羊血清样本。通过间接血凝试验，对每份样本的6种血清型特异性抗体进行检测。结果显示，样本血清阳性率高达90.17%（541/600），所有血清学阳性动物均呈现多重血清型混合感染。各血清型的阳性率分别为：A7型最高（77.83%），其次为A2型（74.33%）、T15型（64%）、T4型（62%）、PA型（60%）及A1型（39.17%）。本研究发现，雌性绵羊[比值比（odds ratio, OR）=2.45，95%置信区间（95% CI）=1.09~5.52，p=0.031]与居住在高海拔地区的绵羊[OR=20.29，95% CI=2.54~161.95，p=0.004]的血清阳性率显著更高。本研究通过面对面访谈开展问卷调查（n=384），以评估养殖户对羊巴氏杆菌病的知识、态度与行为。结果显示，多数受访者（72.4%）对该疾病的知识水平不足；对该疾病持积极态度、拥有良好行为的养殖户占比分别为50.26%与77.6%。本研究结果充分表明，羊巴氏杆菌病在研究区域内广泛流行，对绵羊养殖业造成了严峻挑战。现有研究显示，不同血清型之间缺乏交叉保护性免疫，这或可解释为何当前使用单血清型多杀性巴氏杆菌A生物型疫苗的免疫策略，无法为疾病暴发提供充分防护。在研发多价疫苗时，应优先选取当地优势血清型，结合其临床重要性与所造成的经济影响，确定纳入疫苗的血清型种类。此外，通过参与式方法对养殖户开展疾病相关核心知识培训，对实施有效的疾病管理策略至关重要。该国其他区域的相关数据，将有助于开发适用于全国范围的高效疫苗。