Comparison of three alternative methods for analysis of equine Faecal Egg Count Reduction Test data.
نویسندگان
چکیده
The Faecal Egg Count Reduction Test (FECRT) is the most widely used method of assessing the efficacy of anthelmintics, and is the only in vivo technique currently approved for use with horses. Equine Faecal Egg Count (FEC) data are frequently characterised by a low mean, high variability, small sample size and frequent zero count observations. Accurate analysis of the data therefore depends on the use of an appropriate statistical technique. Analyses of simulated FECRT data by methods based on calculation of the empirical mean and variance, non-parametric bootstrapping, and Markov chain Monte Carlo (MCMC) are compared. The MCMC method consistently outperformed the other methods, independently of the distribution from which the data were generated. Bootstrapping produced notional 95% confidence intervals containing the true parameter as little as 40% of the time with sample sizes of less than 50. Analysis of equine FECRT data yielded inconclusive results in 53 of 63 (84%) datasets, suggesting that the routine use of prior sample size calculations should be adopted to ensure sufficient data are collected. The authors conclude that computationally intensive parametric methods such as MCMC be used for analysis of FECRT data with sample sizes of less than 50, in order to avoid erroneous inference about the true efficacy of anthelmintics in the field.
منابع مشابه
Evaluating faecal egg count reduction using a specifically designed package "eggCounts" in R and a user friendly web interface.
The seemingly straightforward task of analysing faecal egg counts resulting from laboratory procedures such as the McMaster technique has, in reality, a number of complexities. These include Poisson errors in the counting technique which result from eggs being randomly distributed in well mixed faecal samples. In addition, counts between animals in a single experimental or observational group a...
متن کاملDetermination of anthelmintic resistance of Haemonchus contortus to three classes of anthelmintics in a Kenyan sheep flock based on results from faecal egg count reduction test
متن کامل
Efficacy of ivermectin against gastrointestinal nematodes of cattle in Denmark evaluated by different methods for analysis of faecal egg count reduction
The efficacy of ivermectin (IVM) against gastrointestinal nematodes in Danish cattle was assessed by faecal egg count reduction test (FECRT). Six cattle farms with history of clinical parasitism and avermectin use were included. On the day of treatment (Day 0), 20 naturally infected calves per farm (total n = 120) were stratified by initial faecal egg counts (FEC) and randomly allocated to a tr...
متن کاملThe recovery of added nematode eggs from horse and sheep faeces by three methods
BACKGROUND Nematode infections in horses are widespread across the world. Increasing levels of anthelmintic resistance, reported worldwide in equine parasites, have led to the creation of programs for the control of nematodes based on faecal egg counts (FEC). To improve nematode egg counting in equine faecal samples and establish whether the matrix of equine faeces or the eggs affect the counts...
متن کاملبررسی صحرایی وجود مقاومت نسبت به آلبندازول در نماتودهای دستگاه گوارش گوسفندان استان خوزستان
In this survey, resistance to albendazole was investigated in 15 sheep flocks from different regions of Khozestan province. On each flock, two groups of 15 sheep including control groups (untreated) and Albendazole group (treated with 5 mg/kg of Albendazole) were selected and the investigation was carried out using faecal egg count reduction test(F.E.C.R.T) for 10 days after treatment. P...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Preventive veterinary medicine
دوره 93 4 شماره
صفحات -
تاریخ انتشار 2010