Kuhnert-Paul Y, Schmäschke R, Daugschies A
Institut für Parasitologie, Leipzig.
Tierarztl Prax Ausg G Grosstiere Nutztiere. 2012;40(1):21-6.
Results of parasitological examination of faecal aliquots may vary between diagnostic laboratories. To examine whether inhomogeneous distribution of worm eggs in faecal samples is responsible for this observation, horse faeces provided for routine diagnosis of helminth infection were examined. Distribution of worm eggs was assessed by examining aliquots taken from different locations of the faecal sample by a combined sedimentation-flotation method (KSFV). In addition, it was tested, whether the homogenization of a larger amount (minimum of 40 g) of faeces before performing KSFV improved reproducibility of the method.
51 faecal samples of horses were examined three times in parallel by KSFV with ZnSO4 solution. 10 g aliquots were taken from the margin (R), from inside (I) and from both locations (G). The remaining amount of faeces was weighed, suspended with water 1:1 and homogenized. Subsequently, three subsamples, each consisting of 20 g of this suspension, were taken and examined by KSFV.
The egg numbers of the nematodes (strongyles and Parascaris equorum ) found in samples that originated from different locations were similar and variation was low. The homogenization of a larger amount of faeces had no relevant impact on egg counts of these nematodes.
Nematode infections are relevant and frequently occurring in the horse, and reliable assessment of worm egg excretion is a critical aspect for rational planning of control measures. It could be shown that the distribution of nematode eggs (strongyles and Parascaris equorum ) in horse faeces is quite even and results are in principle reproducible if 10 g faeces are examined by KSFV. The homogenization of a larger amount of faeces does not improve the sensitivity or reproducibility of KSFV, and is thus dispensable. For diagnostic purposes, it is advisable to ship approximately 50g of horse faeces to the laboratory.
粪便等分样本的寄生虫学检查结果在不同诊断实验室之间可能存在差异。为了检验粪便样本中蠕虫卵分布不均是否是导致这一现象的原因，我们对用于蠕虫感染常规诊断的马粪便进行了检查。通过联合沉淀浮选法（KSFV）检查取自粪便样本不同位置的等分样本，评估蠕虫卵的分布情况。此外，还测试了在进行KSFV之前将大量（至少40克）粪便匀化是否能提高该方法的可重复性。
采用硫酸锌溶液通过KSFV对51份马粪便样本进行了三次平行检测。从边缘（R）、内部（I）以及这两个位置（G）采集10克等分样本。称取剩余粪便量，按1:1加水悬浮并匀化。随后，取三个各20克该悬浮液的子样本，通过KSFV进行检测。
来自不同位置的样本中发现的线虫（圆线虫和马副蛔虫）虫卵数量相似，变异程度较低。大量粪便的匀化对这些线虫的虫卵计数没有显著影响。
线虫感染在马匹中较为常见且具有相关性，可靠评估虫卵排泄情况是合理规划防控措施的关键环节。结果表明，马粪便中线虫卵（圆线虫和马副蛔虫）的分布相当均匀，原则上如果通过KSFV检测10克粪便，结果是可重复的。大量粪便的匀化并不能提高KSFV的敏感性或可重复性，因此是不必要的。出于诊断目的，建议向实验室运送约50克马粪便。
