Elephant endotheliotropic herpesvirus (EEHV) can cause EEHV hemorrhagic disease (EEHVHD),
leading to significant mortality in captive and free-ranging, young Asian and African
elephants. Infection has profound implications for elephant population growth and sustainably.
Knowing which tissues and cells the virus infects (tropism) to elicit disease is critical for
understanding mechanisms of infection, dissemination, and shedding. Because viral inclusions
are rare, however, determination of viral tropism requires sensitive methods. This study utilizes a
novel in-situ hybridization technique (RNAscope®) to detect and localize EEHV1A in Asian
elephant tissues with EEHV-HD lesions. RNAscope® offers enhanced specificity and sensitivity
as compared with conventional protocols especially in archival samples. Results will provide
validation of RNAscope® protocols in elephant tissue for use in future investigations and
possibly for diagnostic testing. Findings will form the foundation for work towards
understanding EEHV-HD pathogenesis. Importantly, knowledge of viral cellular/tissue tropism
may enhance prevention and treatment strategies.