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

Jeffrey J. Stanton Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030.

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Jian-Chao Zong Viral Oncology Program, School of Medicine, Johns Hopkins University, Baltimore, MD 21201.

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Erin Latimer Elephant Herpesvirus Laboratory, Smithsonian National Zoological Park, 3001 Connecticut Ave NW, Washington, DC 20013.

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Jie Tan Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030.

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Alan Herron Center for Comparative Medicine and Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX 77030.

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Gary S. Hayward Viral Oncology Program, School of Medicine, Johns Hopkins University, Baltimore, MD 21201.

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Paul D. Ling Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030.

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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.

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.

Contributor Notes

Supported by Houston Zoo Incorporated, Elephant Managers Association, and National Institutes of Health training grant T32-AI-07471.

Address correspondence to Dr. Ling (pling@bcm.edu).
  • 1.

    Ossent PGuscetti FMetzler AE, et al.Acute and fatal herpesvirus infection in a young Asian elephant (Elephas maximus). Vet Pathol 1990;27:131133.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 2.

    Richman LKMontali RJGarber RL, et al.Novel endotheliotropic herpesviruses fatal for Asian and African elephants. Science 1999;283:11711176.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 3.

    Richman LKMontali RJCambre RC, et al.Clinical and pathological findings of a newly recognized disease of elephants caused by endotheliotropic herpesviruses. J Wildl Dis 2000;36:112.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 4.

    Fickel JRichman LKMontali R, et al.A variant of the endotheliotropic herpesvirus in Asian elephants (Elephas maximus) in European zoos. Vet Microbiol 2001;82:103109.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 5.

    Garner MMHelmick KOchsenreiter J, et al.Clinico-pathologic features of fatal disease attributed to new variants of endotheliotropic herpesviruses in two Asian elephants (Elephas maximus). Vet Pathol 2009;46:97104.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 6.

    Ehlers BBurkhardt SGoltz M, et al.Genetic and ultrastructural characterization of a European isolate of the fatal endotheliotropic elephant herpesvirus. J Gen Virol 2001;82:475482.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 7.

    Reid CEHildebrandt TBMarx N, et al.Endotheliotropic elephant herpes virus (EEHV) infection. The first PCR-confirmed fatal case in Asia. Vet Q 2006;28:6164.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 8.

    Metzler AEOssent PGuscetti F, et al.Serological evidence of herpesvirus infection in captive Asian elephants (Elephas maximus). J Wildl Dis 1990;26:4149.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 9.

    Zong JCLatimer EHeaggans S, et al.Analysis of species and strain differences among elephant endotheliotropic herpesviruses by gene subtyping: absence of epidemiological connections among 20 cases of EEHV1 associated with acute hemorrhagic disease in captive Asian elephants, in Proceedings. 2010 Int Elephant Conserv Res Symp 2010; in press.

    • Search Google Scholar
    • Export Citation
  • 10.

    Richman LKMontali RJHayward GS. Review of a newly recognized disease of elephants caused by endotheliotropic herpesviruses. Zoo Biol 2000;19:383392.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 11.

    Schmitt DLHardy DAMontali RJ, et al.Use of famciclovir for the treatment of endotheliotrophic herpesvirus infections in Asian elephants (Elephas maximus). J Zoo Wildl Med 2000;31:518522.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 12.

    Ehlers BDural GMarschall M, et al.Endotheliotropic elephant herpesvirus, the first betaherpesvirus with a thymidine kinase gene. J Gen Virol 2006;87:27812789.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 13.

    Davison AJEberle REhlers B, et al.The order Herpesvirales. Arch Virol 2009;154:171177.

  • 14.

    Zong JCLatimer EHeaggans S, et al.Pathogenesis and molecular epidemiology of fatal elephant endotheliotropic disease associated with the expanding Proboscivirus genus of the Betaherpesvirinae, in Proceedings. 2007 Int Elephant Conserv Res Symp 2008;2335.

    • Search Google Scholar
    • Export Citation
  • 15.

    Wellehan JFJohnson AJChildress AL, et al.Six novel gammaherpesviruses of Afrotheria provide insight into the early divergence of the Gammaherpesvirinae. Vet Microbiol 2008;127:249257.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 16.

    Fickel JLieckfeldt DRichman LK, et al.Comparison of glycoprotein B (gB) variants of the elephant endotheliotropic herpesvirus (EEHV) isolated from Asian elephants (Elephas maximus). Vet Microbiol 2003;91:1121.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 17.

    Pellett PERoizman B. The family Herpesviridae: a brief introduction. In: Knipe DMHowley PM, eds. Fields' virology. Philadelphia: Lippincott Williams & Wilkins, 2007;24792499.

    • Search Google Scholar
    • Export Citation
  • 18.

    Jacobson ERSundberg JPGaskin JM, et al.Cutaneous papillomas associated with a herpesvirus-like infection in a herd of captive African elephants. J Am Vet Med Assoc 1986;189:10751078.

    • Search Google Scholar
    • Export Citation
  • 19.

    Ling PDLednicky JAKeitel WA, et al.The dynamics of herpesvirus and polyomavirus reactivation and shedding in healthy adults: a 14-month longitudinal study. J Infect Dis 2003;187:15711580.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 20.

    Hadinoto VShapiro MSun CC, et al.The dynamics of EBV shedding implicate a central role for epithelial cells in amplifying viral output. PLoS Pathog [serial online] 2009;5:e1000496. Available at: www.plospathogens.org/article/info:doi%2F10.1371%2Fjournal.ppat.1000496. Accessed Jun 14, 2009.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 21.

    Ratcliff RMChang GKok T, et al.Molecular diagnosis of medical viruses. Curr Issues Mol Biol 2007;9:87102.

  • 22.

    Ochert ASBoulter AWBirnbaum W, et al.Inhibitory effect of salivary fluids on PCR: potency and removal. PCR Methods Appl 1994;3:365368.

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