Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: August 1, 2013
Publication Date: N/A
Technical Abstract: Accurate diagnosis of bovine viral diarrhea virus (BVDV) induced reproductive disease is important to herd health management and BVDV control programs. Diagnosing BVDV, by polymerase chain reaction (PCR), as a cause of reproductive disease may be problematic because viral nucleic acid may be degraded in aborted or stillborn fetuses due to • exposure to the autolytic microenvironment in the time between fetal death and expulsion and • exposure to heat, light and tissue breakdown in the time between expulsion and discovery in pens and pastures. The purpose of this study was to examine the stability of viral nucleic acid in fetal tissues exposed to different conditions. To this end, 7 first calf heifers, 6 naïve and one vaccinated, were exposed to BVDV1b strain CA0401186a at 84 to 86 days gestation. Fetuses were harvested by cesarean section at 115 -117 days of gestation. The 6 fetuses removed from the non-vaccinated heifers were BVDV positive based on virus isolation while the one fetus from the vaccinated animal was negative. The following samples were collected: brain, organ pool A (heart, lungs, thymus), organ pool B (spleen, kidney, intestines), ears, muscle and skin from back leg. These samples were processed as follows; a. No storage – processed immediately b. No storage, inoculate with fecal matter and processed immediately c. 7 days, -80 C d. 7 days, -80 C inoculated with fecal matter e. 7 days, 4 C f. 7 days, 4 C inoculated with fecal matter g. 7 days, room temperature (RMT) h. 7 days, RMT inoculated with fecal matter I. 7 days, 37 C j. 7 days, 37 C inoculated with fecal matter A polymerase chain reaction test based on amplification of sequences from the 5’ UTR was used for detection. Fecal contamination did not appear to decrease detection. No difference in detection by polymerase chain reaction (PCR) was observed in samples stored under conditions a through f. Detection under storage conditions g through j varied by tissue sample with organ pool B samples showing the most variation. These results indicate that BVDV nucleic acid is stable under a wide range of conditions and that PCR based tests can be reliable for detection of BVDV from abortion and stillbirth cases.