Cook Elizabeth A J, Sitt Tatjana, Poole E Jane, Ndambuki Gideon, Mwaura Stephen, Chepkwony Maurine C, Latre de Late Perle, Miyunga Antoinette A, van Aardt Richard, Prettejohn Giles, Wragg David, Prendergast James G D, Morrison W Ivan, Toye Philip
Livestock Genetics, International Livestock Research Institute (ILRI), Nairobi, Kenya.
Centre for Tropical Livestock Genetics and Health (CTLGH), International Livestock Research Insitute (ILRI) Kenya, Nairobi, Kenya.
Front Vet Sci. 2021 Sep 29;8:731238. doi: 10.3389/fvets.2021.731238. eCollection 2021.
Corridor disease (CD) is a fatal condition of cattle caused by buffalo-derived . Unlike the related condition, East Coast fever, which results from infection with cattle-derived , CD has not been extensively studied. We describe in detail the clinical and laboratory findings in cattle naturally infected with buffalo-derived . Forty-six cattle were exposed to buffalo-derived under field conditions at the Ol Pejeta Conservancy, Kenya, between 2013 and 2018. The first signs of disease observed in all animals were nasal discharge (mean day of onset was 9 days post-exposure), enlarged lymph nodes (10 days post-exposure), and pyrexia (13.7 days post-exposure). Coughing and labored breathing were observed in more than 50% of animals (14 days post-exposure). Less commonly observed signs, corneal edema (22%) and diarrhea (11%), were observed later in the disease progression (19 days post-exposure). All infections were considered clinically severe, and 42 animals succumbed to infection. The mean time to death across all studies was 18.4 days. The mean time from onset of clinical signs to death was 9 days and from pyrexia to death was 4.8 days, indicating a relatively short duration of clinical illness. There were significant relationships between days to death and the days to first temperature (chi = 4.00, = 0.046), and days to peak temperature (chi = 25.81, = 0.001), animals with earlier onset pyrexia died sooner. These clinical indicators may be useful for assessing the severity of disease in the future. All infections were confirmed by the presence of macroschizonts in lymph node biopsies (mean time to parasitosis was 11 days). Piroplasms were detected in the blood of two animals (4%) and 20 (43%) animals seroconverted. In this study, we demonstrate the successful approach to an experimental field study for CD in cattle. We also describe the clinical progression of CD in naturally infected cattle, including the onset and severity of clinical signs and pathology. Laboratory diagnoses based on examination of blood samples are unreliable, and alternatives may not be available to cattle keepers. The rapid development of CD requires recognition of the clinical signs, which may be useful for early diagnosis of the disease and effective intervention for affected animals.
走廊病（CD）是一种由水牛源[病原体名称缺失]引起的牛致命疾病。与由牛源[病原体名称缺失]感染导致的相关疾病东海岸热不同，走廊病尚未得到广泛研究。我们详细描述了自然感染水牛源[病原体名称缺失]的牛的临床和实验室检查结果。2013年至2018年期间，在肯尼亚的奥尔佩杰塔自然保护区，46头牛在野外条件下接触了水牛源[病原体名称缺失]。所有动物出现的首个疾病迹象是鼻液（平均发病时间为接触后9天）、淋巴结肿大（接触后10天）和发热（接触后13.7天）。超过50%的动物出现咳嗽和呼吸困难（接触后14天）。较少见的迹象，角膜水肿（22%）和腹泻（11%），在疾病进展后期出现（接触后19天）。所有感染在临床上都被认为很严重，42头牛死于感染。所有研究中平均死亡时间为18.4天。从临床症状出现到死亡的平均时间为9天，从发热到死亡的平均时间为4.8天，表明临床疾病持续时间相对较短。死亡天数与首次体温出现天数之间存在显著关系（卡方 = 4.00，P = 0.046），以及与体温峰值天数之间存在显著关系（卡方 = 25.81，P = 0.001），发热出现较早的动物死亡更快。这些临床指标未来可能有助于评估疾病的严重程度。所有感染通过淋巴结活检中存在大裂殖体得到证实（平均寄生虫感染时间为11天）。在两只动物（4%）的血液中检测到梨形虫，20只动物（43%）血清转化。在本研究中，我们展示了针对牛走廊病进行实验性野外研究的成功方法。我们还描述了自然感染牛中走廊病的临床进展，包括临床症状和病理的出现及严重程度。基于血液样本检查的实验室诊断不可靠，而养牛户可能没有其他可用的诊断方法。走廊病的快速发展需要识别临床症状，这可能有助于疾病的早期诊断和对患病动物的有效干预。
