BACKGROUND In Vietnam, lack of animal health information is considered a major challenge for pig production. The main objective of this study was to assess the seroprevalences of five pathogens [porcine circovirus type 2 (PCV2), porcine reproductive and respiratory syndrome virus (PRRSV), mycoplasma hyopneumoniae (M. hyo), Japanese encephalitis virus (JEV) and leptospirosis] and to better characterize the farm movements through a survey. RESULTS A total of 600 samples were collected from 120 farms from Bac Giang and Nghe An. Among unvaccinated herds, the highest seroprevalence was found for JE with 73.81% (95% CI: 68.39-78.74) in Bac Giang and 53.51% (95% CI 47.68-59.27) in Nghe An. Seroprevalences for PCV2 and M.hyo were 49.43% (95% CI: 45.06-53.80) and 46.06% (95% CI: 41.48-50.69) among unvaccinated animals. Accumulative co-infections for JE (86.25%) showed the highest level followed by M. hyo (66.25%) and PCV2 (62.50%). Three co-infections with JE had the highest positive rate (28.75%) followed by four co-infections (25.0%). Medium farms had relatively higher herd prevalences for all pathogens, except from leptospirosis. Overall, farmers exported/imported their pigs at the most 1-2 times every 6 months. Some respondents (5% for exportation and 20% for importation) had moved pigs more than 6 times over the last 6 months. CONCLUSIONS Our study provided another pool of evidence that showed that PCV2, PRRS and H. hyo are endemic in pigs in Vietnam. Given the economic impacts of these pathogens elsewhere, the findings confirm the need for studies to evaluate the association between antibody response and clinical relevance as well as to assess the economic impact of co-infections at farm level. We also found that high seroprevalences of JE and leptospirosis were detected in pigs. From a pubic health point of view, it is crucial to raise public awareness especially for high risk occupations (mainly pig farm workers).

中文翻译：

---

越南两个省的猪中多种病原体的血清阳性率和猪场运动的描述。

背景技术在越南，缺乏动物健康信息被认为是养猪业的主要挑战。这项研究的主要目的是评估5种病原体的血清流行率[猪圆环病毒2型（PCV2），猪繁殖与呼吸综合征病毒（PRRSV），猪肺炎支原体（h。hyo），日本脑炎病毒（JEV）和钩端螺旋体病]并通过调查更好地表征农场的动向。结果总共从Bac Giang和Nghe An的120个农场收集了600个样本。在未接种疫苗的牛群中，Bac Giang的JE血清阳性率最高，在Nghe An中为73.81％（95％CI：68.39-78.74），在Nghe An为53.51％（95％CI 47.68-59.27）。在未接种疫苗的动物中，PCV2和M.hyo的血清阳性率为49.43％（95％CI：45.06-53.80）和46.06％（95％CI：41.48-50.69）。JE的累积共感染（86.25％）显示最高水平，其次是猪肺炎支原体（66.25％）和PCV2（62.50％）。三种合并感染的JE阳性率最高（28.75％），其次是四种合并感染（25.0％）。中型养殖场除钩端螺旋体病外，所有病原体的猪群流行率均较高。总体而言，农民每6个月最多出口1-2次猪。在过去的六个月中，一些受访者（出口占5％，进口占20％）移动了6次以上。结论我们的研究提供了另一组证据，表明越南的猪中PCV2，PRRS和H. hyo是地方病。考虑到这些病原体对其他地方的经济影响，这些发现证实，有必要进行研究以评估抗体反应与临床相关性之间的关联以及评估农场共同感染的经济影响。我们还发现在猪中发现了高血清阳性率的脑脊髓炎和钩端螺旋体病。从公共卫生的角度出发，至关重要的是提高公众的意识，特别是对于高风险职业（主要是养猪场的工人）。