Detection and characterisation of multiple herpesviruses in free-living Western European hedgehogs (Erinaceus europaeus)

Sporadic cases of herpesvirus-associated disease have been reported in the Western European hedgehog (Erinaceus europaeus), but there has been little surveillance for, nor any sequence characterisation of, herpesviruses in this species to date. A nested pan-herpesvirus polymerase chain reaction (PCR) targeting a region of the DNA polymerase gene was used to test 129 Western European hedgehogs from across Great Britain, 2011–2016; 59 (46%) of which were PCR-positive. In addition, samples from two previously published cases of fatal herpesvirus infection in E. europaeus, from Sweden and Switzerland, were positive using this PCR. No statistically significant relationship was detected between PCR result and sex, age class, year or season for the British hedgehogs tested. In most PCR-positive animals (19/22) from which liver and brain were tested separately, both were PCR-positive. Sanger sequencing of amplicons from 59 British hedgehogs revealed at least two novel viruses within the Gammaherpesvirinae. Thirteen of these hedgehogs had liver and brain tissues screened for microscopic abnormalities, of which one had non-suppurative meningoencephalitis, but neither intranuclear inclusion bodies nor herpesvirus virions (on electron microscopical examination) were identified. Sequencing of the whole DNA polymerase gene confirmed two genetically different Human alphaherpesvirus 1 viruses in the Swedish and Swiss hedgehogs.