Development of in situ hybridization for detection of elephant endotheliotropic herpesvirus in Asian elephants.

Elephant endotheliotropic herpesvirus (EEHV) is one of the most important viral infectious diseases affecting the elephant population worldwide, especially juveniles and young adults. We developed a chromogenic in situ hybridization (ISH) test for detection of EEHV in Asian elephants ( Elephas maximus). Digoxigenin (DIG) DNA probes from the polymerase and terminase genes of EEHV were synthesized using a PCR DIG-labeling method, and detection of hybridized probe to target EEHV DNA was carried out by anti-DIG immunolabeling. Distribution of EEHV-1A and EEHV-4 genomes was found to be prominent in mononuclear phagocytic cells of spleen and endothelial cells of visceral organs. ISH enables the detection of EEHV infection and has applications in understanding pathogenesis of EEHV in Asian elephants.