Institute for Parasitology and Tropical Veterinary Medicine, Freie Universitaet Berlin, Berlin, Germany.
Department of Parasitology, Bangladesh Agricultural University, Mymensingh, Bangladesh.
Transbound Emerg Dis. 2018 Apr;65(2):e231-e242. doi: 10.1111/tbed.12745. Epub 2017 Nov 8.
Tick-borne diseases are considered a major hindrance to the health and productive performance of cattle in Bangladesh. To elucidate the epidemiology of tick-borne pathogens (TBPs) in local cattle, a cross-sectional study was performed in the 12 subdistricts (Upazilas) of Mymensingh district in Bangladesh. Blood samples and ticks were collected from 384 clinically healthy cattle kept by 135 farmers from 96 randomly selected villages. DNA extracted from the blood samples was subsequently screened by polymerase chain reaction (PCR) and a Reverse Line Blot (RLB) hybridization assay using an in-house prepared chemiluminescence solution for the presence of Anaplasma, Ehrlichia, Rickettsia, Babesia and Theileria spp. A total of 2,287 ticks were collected from 232 infested cattle (60.4%, 232/384) and identified morphologically as Rhipicephalus (Boophilus) microplus (n = 1,432, 62.6%) and Haemaphysalis bispinosa (n = 855; 37.4%). The RLB results demonstrated that the majority of the cattle (62.2%) were infected with at least one TBP. Theileria orientalis infections were most common (212/384, 55.2%) followed by infections with Anaplasma bovis (137/384, 35.67%), Anaplasma marginale (16/384, 4.17%), Babesia bigemina (4/384, 1.04%) and Babesia bovis (2/384, 0.52%). A previously uncharacterized Anaplasma sp. (Anaplasma sp. Mymensingh) and Babesia sp. (Babesia sp. Mymensingh), which are genetically closely related to Anaplasma platys and B. bigemina, were detected in 50 of 384 (13.0%) and 1 of 384 (0.3%) of the blood samples, respectively. Key risk factors for the occurrence of T. orientalis, A. marginale and Anaplasma sp. Mymensingh were identified. In conclusion, this study revealed that cattle in Mymensingh district are mainly infested with R. microplus and H. bispinosa ticks and may carry multiple TBPs. In addition, two previously uncharacterized pathogens were detected in the bovine blood samples. The pathogenicity of these species remains to be determined.
在孟加拉国，蜱传疾病被认为是影响牛群健康和生产性能的主要因素。为了阐明当地牛群中蜱传病原体（TBPs）的流行病学情况，在孟加拉国迈门辛县的 12 个分区（Upazilas）进行了一项横断面研究。从 135 名农民饲养的 384 头临床健康牛中采集了血液样本和蜱虫。从血液样本中提取的 DNA 随后通过聚合酶链反应（PCR）和使用内部制备的化学发光溶液进行的反向线杂交（RLB）分析，以检测是否存在无形体、埃立克体、立克次体、巴贝虫和泰勒虫属。从 232 头受感染的牛（60.4%，232/384）中总共采集了 2287 只蜱虫，这些蜱虫通过形态学鉴定为璃眼蜱（Boophilus）微纤体（n=1432，62.6%）和双扇硬蜱（n=855；37.4%）。RLB 结果表明，大多数牛（62.2%）至少感染了一种 TBP。东方泰勒虫感染最为常见（212/384，55.2%），其次是牛无形体感染（137/384，35.67%）、边缘无形体感染（16/384，4.17%）、双芽巴贝斯虫感染（4/384，1.04%）和牛巴贝斯虫感染（2/384，0.52%）。在 384 份血液样本中，检测到了一种以前未被描述的无形体（迈门辛无形体）和一种巴贝斯虫（迈门辛巴贝斯虫），这两种病原体与边缘无形体和双芽巴贝斯虫在基因上密切相关，分别在 50 份（13.0%）和 1 份（0.3%）血液样本中被发现。确定了东方泰勒虫、边缘无形体和迈门辛无形体发生的关键风险因素。总之，本研究表明，迈门辛地区的牛主要感染璃眼蜱和双扇硬蜱，并可能携带多种 TBPs。此外，在牛的血液样本中还检测到了两种以前未被描述的病原体。这些物种的致病性还有待确定。
