Mbindyo Christine M, Gitao George C, Mulei Charles M
University of Nairobi, College of Agriculture and Veterinary Sciences, Department of Veterinary Pathology, Microbiology and Parasitology, P.O. Box 29053-00625, Kangemi, Nairobi, Kenya.
University of Nairobi, College of Agriculture and Veterinary Sciences, Department of Clinical Studies, P.O. Box 29053-00625, Kangemi, Nairobi, Kenya.
Vet Med Int. 2020 Aug 4;2020:8831172. doi: 10.1155/2020/8831172. eCollection 2020.
Bovine mastitis continues to be a leading cause of heavy economic losses in the dairy industry and a public health hazard globally. This cross-sectional study investigated the prevalence, etiologies of clinical and subclinical mastitis, and associated predisposing factors in Embu and Kajiado counties in Kenya. A semistructured questionnaire was administered to 154 smallholder dairy farmers to collect data on management practices, animal factors, and disease history. A total of 395 dairy cows were initially screened for subclinical mastitis using the California mastitis test (CMT), and milk samples were aseptically collected. Both CMT positive and CMT negative samples were analyzed using conventional bacteriological isolation and identification procedures. In the present study, the overall prevalence of mastitis based on CMT and clinical examination was 80% (316/395), out of which 6.8% (27/395) was clinical mastitis, while 73.1% (289/395) was subclinical mastitis. Based on culture, the overall prevalence of clinical and subclinical mastitis was 51.6% (815/1580), 74.4% (294/395), and 76.6% (118/154) at the quarter, cow, and farm level, respectively. From the 1574 milk samples analyzed by cultured, 1016 bacteria were yielded. The predominant bacteria were coagulase-negative (CNS), 42.8% (435/1016), and in decreasing order, , 22.2% (226/1016), , 15.7% (160/1016), and , 5.1% (52/1016), and the least was species, 0.7% (7/1016), while 23.7% of the sample yielded no bacterial growth. Risk factor analysis revealed that milking mastitic cows last (=0.002), using a clean udder drying towel for each cow (=0.033) and previous history of mastitis (=0.046) were significantly associated with presence of mastitis. The current study has shown a relatively high prevalence of subclinical mastitis with CNS as predominant bacteria. Therefore, control measures are urgently warranted. Management factors such as milking mastitic cows last, using a clean towel for udder drying for each cow, and culling mastitic cows should be considered and included in the Kenyan mastitis control programs.
奶牛乳腺炎仍然是乳制品行业经济损失惨重的主要原因，也是全球公共卫生的一大隐患。这项横断面研究调查了肯尼亚恩布县和卡贾多县临床和亚临床乳腺炎的患病率、病因及相关诱发因素。向154位小农户奶农发放了一份半结构化问卷，以收集有关管理措施、动物因素和疾病史的数据。最初使用加利福尼亚乳腺炎检测法（CMT）对395头奶牛进行亚临床乳腺炎筛查，并无菌采集牛奶样本。对CMT呈阳性和CMT呈阴性的样本均采用传统细菌学分离和鉴定程序进行分析。在本研究中，基于CMT和临床检查的乳腺炎总体患病率为80%（316/395），其中临床乳腺炎占6.8%（27/395），亚临床乳腺炎占73.1%（289/395）。基于培养结果，临床和亚临床乳腺炎在季度、奶牛和农场层面的总体患病率分别为51.6%（815/1580）、74.4%（294/395）和76.6%（118/154）。在通过培养分析的1574份牛奶样本中，分离出1016株细菌。主要细菌为凝固酶阴性葡萄球菌（CNS），占42.8%（435/1016），其次依次为金黄色葡萄球菌，占22.2%（226/1016），无乳链球菌，占15.7%（160/1016），停乳链球菌，占5.1%（52/1016），最少的是嗜热栖热菌，占0.7%（7/1016），而23.7%的样本未培养出细菌。风险因素分析显示，最后挤患乳腺炎奶牛的奶（=0.002）、每头奶牛使用干净的乳房擦干毛巾（=0.033）以及既往乳腺炎病史（=0.046）与乳腺炎的发生显著相关。当前研究表明亚临床乳腺炎患病率相对较高，且以CNS为主要细菌。因此，迫切需要采取控制措施。应考虑将诸如最后挤患乳腺炎奶牛的奶、每头奶牛使用干净毛巾擦干乳房以及淘汰患乳腺炎奶牛等管理因素纳入肯尼亚乳腺炎控制计划。
