Filter-Paper Blood Sampling for Detection of Pathogen Exposure and Pregnancy in Caribou

Pathogens: For all eight pathogens initially investigated, serological testing (detection of antibodies in serum vs. filter paper [FP] samples) was done in duplicate at diagnostic laboratories. Serum and FP data were generated from competitive enzyme-linked immunoassay (c-ELISA) for Brucella, West Nile virus, Neospora caninum; from indirect-ELISA for Brucella, bovine herpesvirus-1, parainfluenza-3 virus, bovine respiratory syncytial virus; and from virus neutralization for bovine viral diarrhea virus types I and II. Quantities of data vary by pathogen. Initial analyses indicate that FP testing is valid (high sensitivity and specificity when FP is compared to serum as the gold standard) for the pathogens and tests noted. Testing continues in order to assess multiple time points (up to a year or longer of storage) and acquire larger sample sizes for some pathogens. A pilot study of collection/storage regimes suggests minimal difference between FP results after frozen storage vs dry storage. A more robust investigation of this is planned.

Progesterone: Initial results indicate that progesterone levels detected from Rangifer FPs are different from (higher than) the levels detected in matched serum samples; however, the difference is consistent. Sample size is small and testing is ongoing but results are promising. It appears reasonable that Rangifer-specific cut-offs could be established to identify animals as "pregnant - yes/no."