Central Veterinary Laboratory, Kathmandu, Nepal.
Institute of Agriculture and Animal Science, Tribhuvan University, Paklihawa, Nepal.
BMC Vet Res. 2021 Mar 25;17(1):132. doi: 10.1186/s12917-021-02835-8.
Brucellosis is a zoonotic disease caused by Brucella spp. In Nepal, the presence of brucellosis in small ruminants, namely sheep and goats, has impacted farmers' livelihood and the food safety of consumers. A cross-sectional study was conducted in Rupandehi district of Nepal during January to March 2020 to investigate the seroepidemiology and associated risk factors of brucellosis in the sheep and goat population. Altogether, 19 sheep and 60 goat farms in the district were visited. Owners were interviewed to get information on animals, including their management and movement patterns. Three hundred fifty-seven samples (80 sheep and 277 goat samples) were collected proportionately based on farm sizes. Each serum sample was tested with Rose Bengal Test and ELISA to estimate the seropositivity of brucellosis. Logistic regression was carried out to calculate corresponding odds ratios of each variable associated with detection of brucellosis.
At the farm level, 31.6% (6/19; 95% CI: 12, 54%) of sheep farms and 3.3% (2/60, 95% CI: 0.9, 11.4%) of goat farms were seropositive to brucellosis. Out of 80 sheep serum samples, 12 (15%; 95% CI: 8.79-24.41%) and out of 277 goat serum samples, three (1.1%; 95% CI: 0.37-3.14%) were seropositive to brucellosis. Age greater than 1.5 years (OR = 5.56, 95% CI: 1.39, 29.38; p = 0.02) and herd size of greater than 100 (OR = 4.74, 95% CI: 1.23, 20.32, p = 0.03) were identified as significant risk factors for seropositivity of brucellosis in the sheep population. While in the goat population, none of the variables was identified as a significant risk factor.
The study provides evidence that the older sheep and the sheep from the large herds were at higher risk of brucellosis. A control program should be put in place immediately in the sheep population because they may transmit infections to other livestock as they were regularly moved for grazing and selling purposes. Also, strict biosecurity measures should be implemented among pastoralists to prevent brucellosis transmission in them. We suggest further one health-based study to reveal the transmission dynamics of brucellosis between animals and humans.
布鲁氏菌病是一种由布鲁氏菌属引起的人畜共患病。在尼泊尔，小反刍动物（绵羊和山羊）中存在布鲁氏菌病，这对农民的生计和消费者的食品安全造成了影响。本研究于 2020 年 1 月至 3 月期间在尼泊尔的鲁潘德希县进行了一项横断面研究，以调查绵羊和山羊群体中布鲁氏菌病的血清流行病学和相关危险因素。总共访问了该县的 19 个绵羊场和 60 个山羊场。对业主进行了访谈，以获取有关动物的信息，包括其管理和移动模式。根据农场规模，按比例采集了 357 个样本（80 个绵羊样本和 277 个山羊样本）。每个血清样本均采用虎红平板试验和 ELISA 进行检测，以估算布鲁氏菌病的血清阳性率。采用 logistic 回归计算与布鲁氏菌病检测相关的每个变量的相应比值比。
在农场层面，31.6%（6/19；95%CI：12，54%）的绵羊场和 3.3%（2/60，95%CI：0.9，11.4%）的山羊场的血清布鲁氏菌病呈阳性。在 80 个绵羊血清样本中，有 12 个（15%；95%CI：8.79-24.41%）和 277 个山羊血清样本中，有 3 个（1.1%；95%CI：0.37-3.14%）呈布鲁氏菌病血清阳性。年龄大于 1.5 岁（OR=5.56，95%CI：1.39，29.38；p=0.02）和畜群规模大于 100（OR=4.74，95%CI：1.23，20.32，p=0.03）被确定为绵羊群体中布鲁氏菌病血清阳性的显著危险因素。而在山羊群体中，没有一个变量被确定为显著危险因素。
本研究表明，年龄较大的绵羊和来自大畜群的绵羊患布鲁氏菌病的风险更高。应立即在绵羊群体中实施控制计划，因为它们经常为放牧和销售目的而转移，可能会将感染传播给其他牲畜。此外，牧民应实施严格的生物安全措施，以防止布鲁氏菌病在他们之间传播。我们建议进行进一步的基于 One Health 的研究，以揭示动物和人类之间布鲁氏菌病的传播动态。
