Olmo L, Dye M T, Reichel M P, Young J R, Nampanya S, Khounsy S, Thomson P C, Windsor P A, Bush R D
The University of Sydney, Sydney School of Veterinary Science, 425 Werombi Road, Camden, NSW 2570, Australia.
The University of Sydney, Sydney School of Veterinary Science, 425 Werombi Road, Camden, NSW 2570, Australia.
Acta Trop. 2018 Jan;177:118-126. doi: 10.1016/j.actatropica.2017.10.007. Epub 2017 Oct 9.
N. caninum, bovine viral diarrhoea virus, Brucella abortus and Leptospira interrogans serovar Hardjo are globally significant reproductive pathogens that cause abortion and reproductive loss in large ruminants. Prevalence information is lacking in Lao People's Democratic Republic (Laos) despite the poor reproductive performance of cattle and buffalo. Serological examination of frozen cattle (n=90) and buffalo (n=61) sera by commercially available enzyme-linked immunosorbent assays provided the first reported screening of some of these pathogens in Laos. Seroprevalence differed amongst these large ruminant species, with N. caninum, BVDV and L. interrogans serovar Hardjo antibodies found in 68.9% (95% CI±11.6), 4.9% (95% CI±5.4) and 3.3% (95% CI±4.5) of buffalo sera, respectively, and in 7.8% (95% CI±5.5), 10.0% (95% CI±6.2) and 22.2% (95% CI±8.6) of cattle sera, respectively. Buffalo sera had a significantly higher seroprevalence of N. caninum compared to cattle (p<0.001) and cattle sera had a significantly higher seroprevalence of L. interrogans serovar Hardjo compared to buffalo (p=0.003). Variability was also observed across provinces for N. caninum in buffalo (p=0.007) and for L. interrogans serovar Hardjo in cattle (p=0.071), suggesting provincial risk factors conducive to pathogen transmission. BVDV and N. caninum seropositivity were negatively associated in buffalo (p=0.018) and cattle (p=0.003). In buffalo, L. interrogans serovar Hardjo and BVDV seropositivity were associated (p=0.035, p=0.039). The identification of antibodies against three major abortifacient pathogens in Laos prompts further research to determine if infection is associated with low reproductive efficiency and the risk factors for infection. This is needed for the development of evidence based prevention strategies for improved large ruminant reproductive management among smallholders in Laos.
犬新孢子虫、牛病毒性腹泻病毒、布鲁氏菌和问号状钩端螺旋体哈德乔血清型是全球重要的繁殖性病原体，可导致大型反刍动物流产和繁殖损失。尽管老挝的牛和水牛繁殖性能较差，但该国缺乏相关流行率信息。通过市售酶联免疫吸附试验对冷冻牛（n = 90）和水牛（n = 61）血清进行血清学检测，首次报道了老挝对其中一些病原体的筛查情况。这些大型反刍动物物种的血清阳性率有所不同，水牛血清中犬新孢子虫、牛病毒性腹泻病毒和问号状钩端螺旋体哈德乔血清型抗体的检出率分别为68.9%（95%置信区间±11.6）、4.9%（95%置信区间±5.4）和3.3%（95%置信区间±4.5），牛血清中的检出率分别为7.8%（95%置信区间±5.5）、10.0%（95%置信区间±6.2）和22.2%（95%置信区间±8.6）。水牛血清中犬新孢子虫的血清阳性率显著高于牛（p < 0.001），牛血清中问号状钩端螺旋体哈德乔血清型的血清阳性率显著高于水牛（p = 0.003）。在水牛中，犬新孢子虫在不同省份的情况存在差异（p = 0.007），在牛中问号状钩端螺旋体哈德乔血清型也存在差异（p = 0.071），这表明存在有利于病原体传播的省级风险因素。在水牛（p = 0.018）和牛（p = 0.003）中，牛病毒性腹泻病毒和犬新孢子虫血清阳性呈负相关。在水牛中，问号状钩端螺旋体哈德乔血清型和牛病毒性腹泻病毒血清阳性相关（p = 0.035，p = 0.039）。在老挝鉴定出针对三种主要流产病原体的抗体，促使开展进一步研究，以确定感染是否与低繁殖效率及感染风险因素有关。这对于制定基于证据的预防策略以改善老挝小农户大型反刍动物的繁殖管理是必要的。
