Detection of pathogenic elephant endotheliotropic herpesvirus in routine trunk washes from healthy adult Asian elephants (Elephas maximus) by use of a real-time quantitative polymerase chain reaction assay

Am J Vet Res. 2010 Aug;71(8):925-33. doi: 10.2460/ajvr.71.8.925.

Abstract

Objective: To investigate the pathogenesis and transmission of elephant endotheliotropic herpesvirus (EEHV1) by analyzing various elephant fluid samples with a novel EEHV1-specific real-time PCR assay.

Animals: 5 apparently healthy captive Asian elephants (Elephas maximus) from the same herd.

Procedures: A real-time PCR assay was developed that specifically detects EEHV1. The assay was used to evaluate paired whole blood and trunk-wash samples obtained from the 5 elephants during a 15-week period. Deoxyribonucleic acid sequencing and viral gene subtyping analysis were performed on trunk-wash DNA preparations that had positive results for EEHV1. Viral gene subtypes were compared with those associated with past fatal cases of herpesvirus-associated disease within the herd.

Results: The PCR assay detected viral DNA to a level of 1,200 copies/mL of whole blood. It was used to detect EEHV1 in trunk secretions of 3 of the 5 elephants surveyed during the 15-week period. Viral gene subtyping analysis identified 2 distinct elephant herpesviruses, 1 of which was identical to the virus associated with a previous fatal case of herpesvirus-associated disease within the herd.

Conclusions and clinical relevance: EEHV1 was shed in the trunk secretions of healthy Asian elephants. Trunk secretions may provide a mode of transmission for this virus. Results of this study may be useful for the diagnosis, treatment, and management of EEHV1-associated disease and the overall management of captive elephant populations.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Cloning, Molecular
  • DNA Primers
  • DNA, Viral / blood
  • DNA, Viral / genetics*
  • Elephants / blood
  • Elephants / virology*
  • Gene Amplification
  • Genes, Viral
  • Genome, Viral
  • Genotype
  • Herpesviridae / classification
  • Herpesviridae / genetics*
  • Herpesviridae / isolation & purification
  • Molecular Sequence Data
  • Mycobacterium tuberculosis / isolation & purification
  • Open Reading Frames
  • Plasmids / genetics
  • Polymerase Chain Reaction / methods
  • Polymerase Chain Reaction / veterinary
  • Reference Values
  • Sequence Alignment
  • Sequence Homology, Nucleic Acid

Substances

  • DNA Primers
  • DNA, Viral