Comparison of the diagnostic sensitivity of a commercially available culture kit and a diagnostic culture test using Diamond's media for diagnosing Tritrichomonas foetus in bulls

Centre for Animal Parasitology, Saskatoon Laboratory, Canadian Food Inspection Agency, Saskatoon, Saskatchewan S7N 2R3, Canada.

A number of different culture media have been described for use in the diagnosis of Tritrichomonas foetus infection in bulls, and recently, a commercial culture kit has become available. The objective of this study was to compare the sensitivity of 2 culture-based diagnostic tests for T. foetus in bulls. One test used a commercial kit for transport and culture of the samples. The other test used a thioglycollate transport medium (TFTM) for transport and a modified Diamond's medium (MDM) for culture of the samples. Twenty-one bulls infected with T. foetus were sampled repeatedly. On each sampling day, samples collected from the left and right sides of the bull were tested with one of the 2 diagnostic tests being compared. The effect of the type of diagnostic test on the outcome of the test was evaluated with a chi-square test for the calculated odds ratio. Because repeated tests from the same bull cannot be considered independent measures, unadjusted chi-square tests were adjusted for the effect of clustering by bull. Samples tested using the commercial kit were 6.95 times as likely to be positive as samples tested with a diagnostic test using MDM (P < 0.001).