APPLICATION OF POLYMERASE CHAIN-REACTION TO DETECT ANIMALS LATENTLY INFECTED WITH AGENTS OF MALIGNANT CATARRHAL FEVER

Oligonucleotide primers derived from alcelaphine herpesvirus 1 (AHV-1) isolate WC11 DNA, the first identified agent of malignant catarrhal f ever (MCF), were used to assay blood lymphocyte DNA using the polymera se chain reaction (PCR). Multiple species of exotic ruminants were exa mined to determine the suitability of this technique for detecting ani mals that may be latently infected. To correlate the PCR results with those of serology, serum samples were obtained from each animal concur rently with lymphocyte collection and subjected to an AHV-1 virus-neut ralization assay (VNA). A total of 86 MCF-susceptible animals were tes ted, and the results of the VNA and PCR assays were compared. PCR resu lts were positive for 44 animals. Of these, 13 were positive by VNA. A nimals positive by both VNA and PCR were all wildebeest, the asymptoma tic carriers of AHV-1, confirming the ability of the primers to amplif y AHV-1 sequence. Positive PCR results from species other than wildebe est may represent sequence amplified from viruses related to AHV-1, wh ich may not induce antibodies capable of neutralizing the WC11 isolate used in the VNA. This study demonstrates that PCR is capable of detec ting the presence of MCF agents in various populations of captive rumi nants prior to the appearance of clinical MCF so that the sources of i nfection can be more reliably ascertained.