A cross-sectional study was carried out to determine foot-and-mouth disease (FMD) seroprevalence and identify risk factors of exposure among cattle herds raised in three zones with different types of land use and progressively distant from the Maasai Mara National Reserve (MMNR) boundary. We selected five villages purposively; two in zone 1 (area < 20 km from the MMNR), another two in zone 2 (area between 20-40 km away from the MMNR) and one in zone 3 (area >40 km away from the MMNR). A total of 1170 cattle sera were collected from 390 herds in all the zones and tested for antibodies against the non-structural proteins (NSPs) of FMD virus (FMDV) using two 3ABC-based Enzyme-Linked Immunosorbent Assay ELISA kits. All sera samples were also screened for serotype-specific antibodies using Solid Phase Competitive ELISA (SPCE) kits (IZSLER, Italy). We targeted FMDV serotypes A, O, South African Territory [SAT] 1 and SAT 2, known to be endemic in East Africa including Kenya. Data on putative risk factors for FMD seropositivity in cattle were collected using a questionnaire. The overall apparent animal-level FMD seroprevalence based on the parallel comparison of the two anti-NSPs ELISA kits was 83.8 % (95 % CI; 81.8-85.9), and differed significantly across zones. Zone 1 had a higher seroprevalence than zones 2 and 3 (χ2 = 116.1, df = 2, p < 0.001). In decreasing order, the overall seroprevalences of FMDV serotypes A, SAT 2, O and SAT 1 were 26.3 % (95 % CI; 23.5-29.2), 21.4 % (95 % CI; 18.8-24.0), 21.2 % (95 % CI; 18.7-23.9) and 13.1 % (95 % CI; 11.1-15.3), respectively. The distribution of these serotypes differed significantly between zones (p < 0.05) except for SAT 2 serotype (χ2 = 0.90, df = 2, p = 0.639). Both serotypes A and O were more prevalent in zones 1 and 2 than zone 3 while serotype SAT 1, was higher in zone 3 compared to other zones. The results of multivariable analyses identified animal sex (i.e., female), raising of cattle in zones 1 and 2 (areas < 40 km away from the MMNR); mixing of cattle from multiple herds at watering points, and pastoral husbandry practices, as significant predictors of animal-level FMD seropositivity. This study established that FMD seroprevalence declined with distance from the MMNR.

中文翻译：

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肯尼亚马赛马拉生态系统中饲养的牛群中口蹄疫病毒的血清流行率。

进行了一项横断面研究，以确定口蹄疫（FMD）的血清流行率，并确定在三个不同土地利用类型且距马赛马拉国家野生动物保护区（MMNR）逐渐远离的地区饲养的牛群中暴露的危险因素）边界。我们有目的地选择了五个村庄。1区中的两个（距MMNR <20 km的区域），2区中的另外两个（距MMNR 20-40 km的区域）和3区中的一个（距MMNR> 40 km的区域）。从所有区域的390个牛群中收集了总共1170头牛血清，并使用两个基于3ABC的酶联免疫吸附测定ELISA试剂盒测试了针对FMD病毒（FMDV）的非结构蛋白（NSP）的抗体。还使用固相竞争ELISA（SPCE）试剂盒（IZSLER，意大利）对所有血清样品进行了血清型特异性抗体筛选。我们针对FMDV血清型A，O，南非领土[SAT] 1和SAT 2，已知在包括肯尼亚在内的东非流行。使用问卷收集了关于牛口蹄疫血清阳性的推定危险因素的数据。根据两种抗NSP ELISA试剂盒的平行比较，总体表观动物水平的FMD血清阳性率为83.8％（95％CI; 81.8-85.9），并且在各个区域之间存在显着差异。1区的血清阳性率高于2区和3区（χ2= 116.1，df = 2，p <0.001）。FMDV血清型A，SAT 2，O和SAT 1的总体血清阳性率以递减顺序分别为26.3％（95％CI; 23.5-29.2），21.4％（95％CI; 18.8-24.0），21.2％（95％CI） ； 18.7-23.9）和13.1％（95％CI; 11.1-15.3）。除SAT 2血清型（χ2= 0）外，这些血清型的分布在区域之间存在显着差异（p <0.05）。90，df = 2，p = 0.639）。与其他区域相比，区域1和2中的血清型A和O在区域1和2中均更为普遍，而区域1中的SAT 1血清型在区域3中则更高。多变量分析的结果确定了动物的性别（即雌性），在1区和2区（距离MMNR <40 km的区域）饲养牛；来自多个畜群在饮水点的牛的混合以及牧业的饲养方式，是动物水平口蹄疫血清反应阳性的重要预测指标。这项研究确定，FMD血清阳性率随距MMNR的距离而下降。距离MMNR 40公里）；来自多个畜群在饮水点的牛的混合以及牧业的饲养方式，是动物水平口蹄疫血清反应阳性的重要预测指标。这项研究确定，FMD血清阳性率随距MMNR的距离而下降。距离MMNR 40公里）；来自多个畜群在饮水点的牛的混合以及牧业的饲养方式，是动物水平口蹄疫血清反应阳性的重要预测指标。这项研究确定，FMD血清阳性率随距MMNR的距离而下降。