title: Zebra Alphaherpesviruses (EHV-1 and EHV-9): Genetic Diversity, Latency and Co-Infections.
abstract: Alphaherpesviruses are highly prevalent in equine populations and co-infections with more than one of these viruses' strains frequently diagnosed. Lytic replication and latency with subsequent reactivation, along with new episodes of disease, can be influenced by genetic diversity generated by spontaneous mutation and recombination. Latency enhances virus survival by providing an epidemiological strategy for long-term maintenance of divergent strains in animal populations. The alphaherpesviruses equine herpesvirus 1 (EHV-1) and 9 (EHV-9) have recently been shown to cross species barriers, including a recombinant EHV-1 observed in fatal infections of a polar bear and Asian rhinoceros. Little is known about the latency and genetic diversity of EHV-1 and EHV-9, especially among zoo and wild equids. Here, we report evidence of limited genetic diversity in EHV-9 in zebras, whereas there is substantial genetic variability in EHV-1. We demonstrate that zebras can be lytically and latently infected with both viruses concurrently. Such a co-occurrence of infection in zebras suggests that even relatively slow-evolving viruses such as equine herpesviruses have the potential to diversify rapidly by recombination. This has potential consequences for the diagnosis of these viruses and their management in wild and captive equid populations.
authors.affiliation: Leibniz-Institute for Zoo and Wildlife Research, Alfred-Kowalke-Strasse 17, Berlin 10315, Germany. azza@izw-berlin.de.
authors.forename: Azza
authors.initials: A
authors.lastname: Abdelgawad
authors.affiliation: Institut für Virologie, Freie Universität Berlin, Robert-von-Ostertag-Str. 7-13, Berlin 14163, Germany. adamiani@zedat.fu-berlin.de.
authors.forename: Armando
authors.initials: A
authors.lastname: Damiani
authors.affiliation: School of Life and Environmental Sciences, University of Sydney, Sydney, NSW 2006, Australia. simon.ho@sydney.edu.au.
authors.forename: Simon Y W
authors.initials: SY
authors.lastname: Ho
authors.affiliation: Tierpark Berlin-Friedrichsfelde, Am Tierpark 125, Berlin 10307, Germany. g.strauss@tierpark-berlin.de.
authors.forename: Günter
authors.initials: G
authors.lastname: Strauss
authors.affiliation: Leibniz-Institute for Zoo and Wildlife Research, Alfred-Kowalke-Strasse 17, Berlin 10315, Germany. szentiks@izw-berlin.de.
authors.forename: Claudia A
authors.initials: CA
authors.lastname: Szentiks
authors.affiliation: Leibniz-Institute for Zoo and Wildlife Research, Alfred-Kowalke-Strasse 17, Berlin 10315, Germany. EAST@izw-berlin.de.
authors.forename: Marion L
authors.initials: ML
authors.lastname: East
authors.affiliation: Institut für Virologie, Freie Universität Berlin, Robert-von-Ostertag-Str. 7-13, Berlin 14163, Germany. no.34@fu-berlin.de.
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Osterrieder
authors.affiliation: Leibniz-Institute for Zoo and Wildlife Research, Alfred-Kowalke-Strasse 17, Berlin 10315, Germany. greenwood@izw-berlin.de.|Department of Veterinary Medicine, Freie Universität Berlin, Oertzenweg 19, Berlin 14163, Germany. greenwood@izw-berlin.de.
authors.forename: Alex D
authors.initials: AD
authors.lastname: Greenwood
keywords: EHV-1; EHV-9; co-occurrence; diversity; latency; zebra