Tydén Eva, Enemark Heidi Larsen, Franko Mikael Andersson, Höglund Johan, Osterman-Lind Eva
Swedish University of Agricultural Sciences, Department of Biomedical Sciences and Veterinary Public Health, Section for Parasitology, Uppsala, Sweden.
Norwegian Veterinary Institute, Department of Animal Health and Food Safety, Oslo, Norway.
Vet Parasitol X. 2019 May 26;2:100013. doi: 10.1016/j.vpoa.2019.100013. eCollection 2019 Nov.
is considered the most pathogenic nematode parasite of the horse. Frequent deworming programs since the 1970s have reduced the prevalence of to low levels, but to the price of widespread benzimidazole resistance in the small strongyles (cyathostominae) and ivermectin resistance especially in the equine roundworm spp. To slow down the progression of anthelmintic resistance in Sweden, horse anthelmintics were made prescription only medicine in 2007 and selective therapy principles were introduced. This means that only individuals with high egg excretion or clinical signs of helminth infection were treated instead of blanket treatment of all horses on a farm. The aims of this study were to investigate the prevalence and risk factors associated with infection in Sweden ten years after the introduction of a selective therapy regime. A total of 529 faecal samples from 106 farms were collected during March to June in 2016 and 2017. A web-based questionnaire was used to collect information about deworming routines. Strongyle faecal egg counts (FEC) were performed by McMaster and presence of was demonstrated with a specific PCR on individual larval cultures. Results were analysed by mixed logistic ( prevalence) or linear (FEC) regression models, where farm was included as random factor. The overall prevalence of at individual and farm levels was 28% and 61%, respectively. We observed a 2.9 increased odds risk of infection on farms that based their treatment on strongyle FEC only as compared to farms that complemented strongyle FECs with larval cultures or dewormed regularly, 1-4 times per year, without prior diagnosis. We found no association between the prevalence of and strongyle FEC level, horse age, geographical region or signs of colic. The prevalence of was 25% in horses shedding ≤150 eggs per gram. Thus horses with low strongyle FECs that are left untreated could be an important source of infection. This may be an important reason for the approximately three-fold increase in prevalence since 1999 in Sweden. However, our combined results indicate that selective therapy based on a combination of strongyle FECs and larval cultivation was not associated with an increased risk of infection. Still, needs to be monitored continuously and should be taken into careful consideration when the treatment frequency is reduced.
被认为是马最具致病性的线虫寄生虫。自20世纪70年代以来频繁的驱虫计划已将其流行率降低到低水平，但代价是小型圆线虫（杯口线虫亚科）对苯并咪唑广泛耐药，尤其是马蛔虫对伊维菌素耐药。为了减缓瑞典驱虫抗性的发展，马用驱虫药在2007年成为仅凭处方购买的药物，并引入了选择性治疗原则。这意味着只对虫卵排泄量高或有蠕虫感染临床症状的个体进行治疗，而不是对农场所有马匹进行全面治疗。本研究的目的是调查在引入选择性治疗方案十年后瑞典马感染该寄生虫的流行率及相关危险因素。在2016年和2017年3月至6月期间，从106个农场共收集了529份粪便样本。使用基于网络的问卷收集有关驱虫程序的信息。通过麦克马斯特法进行圆线虫粪便虫卵计数（FEC），并通过对单个幼虫培养物进行特异性PCR来检测该寄生虫的存在。结果通过混合逻辑（流行率）或线性（FEC）回归模型进行分析，其中将农场作为随机因素纳入。个体和农场层面该寄生虫的总体流行率分别为28%和61%。我们观察到，与那些通过幼虫培养补充圆线虫FEC或每年定期驱虫1 - 4次且无预先诊断的农场相比，仅基于圆线虫FEC进行治疗的农场感染该寄生虫的风险增加了2.9倍。我们发现该寄生虫的流行率与圆线虫FEC水平、马的年龄、地理区域或绞痛症状之间没有关联。在每克粪便中排出≤150个虫卵的马匹中，该寄生虫的流行率为25%。因此，未接受治疗的圆线虫FEC低的马匹可能是该寄生虫感染的重要来源。这可能是自1999年以来瑞典该寄生虫流行率增加约三倍的一个重要原因。然而，我们的综合结果表明，基于圆线虫FEC和幼虫培养相结合的选择性治疗与该寄生虫感染风险增加无关。尽管如此，仍需要持续监测该寄生虫，并且在降低治疗频率时应仔细考虑。
