Researchers from Baylor College of Medicine and Johns Hopkins School of Medicine have been successful in isolating the first genome of the elephant endotheliotropic herpesviruses (EEHV) that affects both managed and free ranging elephants. Although common in both Asian and African elephants, the virus is associated with a more fatal disease in Asian elephants.
The results of this remarkable discovery appeared in the scientific journal Genome Announcements, indicating that the isolated species of elephant endotheliotropic herpesviruses (EEHV) is so unique in characteristics that it could establish a new herpesvirus subfamily category.
About elephant endotheliotropic herpesviruses (EEHV):
Associate professor of molecular virology and microbiology at Baylor College of Medicine, Dr. Paul Ling suggests that EEVH1A is perhaps the most common viral agent encountered in the hemorrhagic disease reported in Asian elephants that is a leading cause of morbidity as well as mortality.
The two teams from Human Genome Sequencing Center at BCM and Viral Oncology Program at Johns Hopkins School of Medicine under the direction of Dr Paul Ling and Dr. Gary S. Hayward utilized a 12-year old DNA sample to isolate the genomic model.
Ling and his associates discovered that many genetic sequences are unique in EEHV1A, different and distinct from other members of the specie.
“All herpes viruses have certain core regions that are similar in terms of what they do, but with EEHV1A, we identified 60 genes that (appear to be unique relative to) not present in other herpesviruses. At this time, we think a new subfamily, in addition to the three subfamilies which categorize the 8 herpesviruses that infect humans, might be needed as we continue to learn more about this virus.”
EEHV is a notable cause of high mortality in Asian elephants. After initial identification in 1995, it took almost 15 years to develop a sequencing model by using real-time PCR test with the collaboration of Houston Zoo and Baylor College of Medicine. The test helps in identification of viral antigens before symptoms even appear in the elephants. Generally, prognosis is poor in symptomatic elephants.
The identification of genetic sequences of elephant endotheliotropic herpesviruses (EEHV) has opened new ways for early identification and is also expected to help researchers in devising a immunologic or pharmacologic therapy to fight the virus. Ling also believe that the identification and sequencing of genes will also enable researchers to understand the overall health status of elephants.