Classical scrapie diagnostic sensitivity per age category in infected goats.

*Mesenteric lymph node.
**Exact one-tailed Cochran-Armitage trend test.
†For official rapid test on obex the analysis included 121 positive cases (17 less than 2 years, 49 between 2 and 3 years and 55 aged 3 years or more).
For each tissue and age category the estimated sensitivity of the diagnostic (Se) and the 95% exact binomial confidence interval (95% CI) of PrPSc detection (assessed using ELISA Biorad TeSeE sheep/goat® results) was computed. The same computation was also done for official rapid tests as performed by state accredited laboratories on obex. Computation relies on data presented in table 1 and assumed that an animal displaying PrPSc accumulation in any of its tissue is scrapie infected.
In all cases, percentages with different letters are significantly different (exact McNemar test p<0.05). For asymptomatic cases, within each row, percentages with different letters are significantly different (Fisher exact test p<0.05).