Herpesvirus Encephalitis in a Little Blue Penguin (Eudyptula minor)

Abstract

<jats:p> An 11-day-old little blue penguin ( Eudyptula minor) died unexpectedly. Prior to hatching, the egg experienced trauma and resultant defects were repaired. The chick hatched without complication and was clinically normal prior to death. Necropsy revealed congested lungs. Histologic examination showed moderate nonsuppurative encephalitis with focally extensive neuronal necrosis and intranuclear inclusions in neurons within necrotic foci. Herpesvirus DNA was detected in brain tissue with a generic herpesvirus polymerase chain reaction. Sanger sequencing demonstrated 100% and 98% sequence homology to sphenicid alphaherpesvirus 1 and penguin herpesvirus 2, respectively. In situ hybridization demonstrated large amounts of herpesvirus nucleic acid in intranuclear inclusions and neuronal nuclei. Combined histology, polymerase chain reaction, Sanger sequencing, and in situ hybridization results were most consistent with herpesviral encephalitis, most likely caused by sphenicid alphaherpesvirus 1. To our knowledge, this is the first report of a herpesvirus infection causing encephalitis in a penguin and the first report of herpesvirus in this species. </jats:p>

Development and analytical characteristics of a quantitative real-time PCR assay for detection of spheniscid alphaherpesvirus 1 in penguins

“…Occurrence and severity of herpesviral infection depends on the host immune status, hostvirus co-evolutionary history, and comorbidities. 9,14,16 Numerous herpesviruses have been detected in taxonomically diverse avian families; however, only 8 avian herpesvirus species in the genera Iltovirus and Mardivirus are currently recognized by the International Committee on Taxonomy of Viruses (ICTV; https://ictv.global/taxonomy): gallid alphaherpesvirus 1 (GaAHV1; syn. infectious laryngotracheitis virus; Iltovirus gallidalpha1), gallid alphaherpesvirus 2 (GaAHV2; syn.…”

“…For example, SpAHV1 has also been detected in a hatchling little blue penguin (Eudyptula minor) with encephalitis, demonstrating that this virus may be clinically important for a variety of penguin species. 16 Virus isolation and conventional consensus PCR have been used to detect SpAHV1; however, the conventional consensus PCR assay used to detect SpAHV1 has a variable limit of detection (LOD) depending on the herpesvirus. 14 Additionally, this assay is not specific for SpAHV1, and DNA sequencing is required to confirm the identity of positive PCR products.…”

“…Occurrence and severity of herpesviral infection depends on the host immune status, host–virus co-evolutionary history, and comorbidities. 9,14,16…”

“…At least 3 genetically distinct herpesviruses have been identified in penguins ( Sphenisciformes , Spheniscidae ): magellanic penguin herpesviruses 1 and 2 (MPHV1, MPHV2) 12 and SpAHV1. 16 MPHV1 was associated with severe, hemorrhagic respiratory disease in 98 oiled juvenile Magellanic penguins ( Spheniscus magellanicus ) presented to a wildlife rehabilitation center in Brazil in June–July 2011. MPHV2 was detected in 5 of 31 (16%) nestling and 4 of 142 (2.8%) adult Magellanic penguins sampled at 4 nesting sites in Argentina during January 2014.…”

Herpesvirus, Flavivirus, and Coronavirus Surveillance in Magnificent Frigatebirds (Fregata magnificens), Alcatrazes Archipelago, Southeastern Brazil

“…The Magnificent Frigatebird herpesviral sequences clustered with other Mardivirus sequences, a genus that includes highly pathogenic viruses such as Gallid alphaherpesvirus 2 , responsible for Marek's disease in poultry (Morrow and Fehler 2004). In seabirds, herpesviruses have been reported and, at times, associated with mortality outbreaks in Suliformes (de Thoisy et al 2009; Niemeyer et al 2017; Sebastiano et al 2017a), Charadriiformes (Sebastiano et al 2020), and Sphenisciformes (Niemeyer et al 2017; Tuxbury et al 2020).…”