Application of a composite faecal egg count procedure in diagnostic parasitology

Egg counts from a simple composite faecal counting procedure using equal amounts of sample from ten sheep were compared statistically against the arithmetic means of the same ten samples prepared by a conventional egg counting method. Forty separate data sets were analysed in an untransformed bivariate plot and after natural logarithmic transformation. A sign test analysis indicated a high degree of similarity between the two data sets. A confidence interval for the composite count (n = 10) was calculated to give a result between five eggs more and 15 eggs less than the arithmetic mean count of the ten samples. When multiple faecal samples are to be examined, the composite method has significant advantages in time saving and increased throughput whilst still providing an accurate result. This technique has been used to monitor gastrointestinal helminthosis and for faecal egg count reduction testing to assess anthelmintic efficacy.