Comparative Genome Analysis of Four Elephant Endotheliotropic Herpesviruses, EEHV3, EEHV4, EEHV5, and EEHV6, from Cases of Hemorrhagic Disease or Viremia

Abstract

One of the factors threatening the long-term survival of endangered Asian elephants in both wild range countries and in captive breeding populations in zoos is a highly lethal hemorrhagic herpesvirus disease that has killed at least 70 young Asian elephants worldwide. The genomes of the first three types of EEHVs (or probosciviruses) identified have been partially characterized in the preceding accompanying paper (L. K. Richman, J.-C. Zong, E. M. Latimer, J. Lock, R. C. Fleischer, S. Y. Heaggans, and G. S. Hayward, J. Virol. 88:13523-13546, 2014, http://dx.doi.org/10.1128/JVI.01673-14). Here we have used PCR DNA sequence analysis from multiple segments of DNA amplified directly from blood or necropsy tissue samples of six more selected cases of hemorrhagic disease to partially characterize four other types of EEHVs from either Asian or African elephants. We propose that all six types and two chimeric subtypes of EEHV belong to multiple lineages of both AT-rich and GC-rich branches within a new subfamily to be named the Deltaherpesvirinae, which evolved separately from all other mammalian herpesviruses about100 million years ago.