Psittacid herpesvirus 3 infection in rose-ringed parakeets in southern Brazil

Abstract

We diagnosed disease caused by psittacid herpesvirus 3 (PsHV-3), a novel psittacid pathogen, in rose-ringed parakeets ( Psittacula krameri) housed in an exotic psittacine breeding colony in southern Brazil. The disease affected several adult birds. Clinical signs included apathy, tachypnea, and wheezing. Four birds were autopsied, and sections of lungs and liver were examined histologically and by electron microscopy (EM), revealing pulmonary congestion, bronchopneumonia, or multifocal necrosis of tertiary bronchi, with syncytial cells and eosinophilic intranuclear inclusion bodies. Viral particles morphologically compatible with herpesviruses were observed by EM in lung sections. PCR with pan-herpesvirus primers performed on total DNA extracted from paraffinized tissue resulted in a 278-bp product. Sequencing of the amplicon revealed 93% nucleotide identity with a PsHV-3 sequence available in GenBank. Phylogenetic analysis grouped the obtained sequence with the only PsHV-3 DNA polymerase gene sequence available (GenBank accession JX028240) and separated the sequence from psittacid herpesviruses 1 and 2. The clinical, pathologic, and molecular findings support the association of PsHV-3 with pneumonia found in these rose-ringed parakeets in southern Brazil.

Herpetic Pneumonia in Indian Ringneck Parrots (Psittacula krameri): First Report of Novel Psittacid Alphaherpesvirus-5 Infection in Europe

“…The authors also reveal that the clinical signs and the gross and histopathological findings associated with PsHV-5 infection are comparable with those previously reported in the literature [ 16 ], attesting the tropism of this virus for the respiratory tract. Among the known pathogenic herpesvirus species affecting the birds belonging to the Psittaciformes order, PsHV-3 has shown to have a tropism for the respiratory tract [ 11 , 15 , 25 ]. It is worth pointing out that other cases of respiratory diseases in parakeets with a herpesvirus as the putative etiology are reported in the literature [ 8 , 26 ]; however, such cases were not investigated at a molecular level, so the etiology remains uncharacterized.…”

“…In addition, PsHV-1 is either able to cause an acute, fatal hepatic necrosis, or to induce neoplastic lesions of both bile and pancreatic ducts long after they have first encountered their host [ 14 ]. In contrast, PsHV-3 has been shown to have a specific tropism for the respiratory tract in different avian species [ 11 , 15 ]. Recently, a novel avian alphaherpesvirus, named Psittacid alphaherpesvirus-5 (PsHV-5), has been detected for the first time in Australia from Indian ringneck parrots ( Psittacula krameri ) showing severe respiratory disease [ 16 ].…”

Naturally occurring psittacid alphaherpesvirus 3 and probable adenovirus coinfection in an Indian ringneck parakeet in the United States

“…But PsAHV-3 might cover a wide geographic distribution with cases documented in the United States and Asia. 9 Herpesviruses can evolve and have low pathogenicity in their natural host. 2 Therefore, it is possible that PsAHV-3 is globally ubiquitous; the latent infection, viral evolution, and gradually low pathogenicity led to diverse disease severity ranging from subclinical to fatal.…”

“…7 Four disease-associated PsAHVs (-1, -2, -3, -5) have been identified in psittacine birds. 1,4,5,[8][9][10]12,15,16 PsAHV-1 is known to cause fatal systemic disease, also known as Pacheco disease, in birds. 10,15 Among the psittacids, Amazon parrots, macaws, and cockatoos are highly susceptible to PsAHV-1, which frequently targets the liver and leads to hepatic necrosis with syncytial cells and intranuclear inclusion bodies (INIBs).…”

Psittacid alphaherpesvirus 5 infection in Indian ringneck parakeets in southern California

“…In 2020, a herpesvirus was reported from Brazil in captive Indian ringneck parrots with respiratory disease, based on a region of the DNA-dependent DNA polymerase gene (GenBank MK922358), which had only 89.5% nucleotide homology with other reported PsAHV3 and PsAHV5 sequences, consistent with a distinct species. 7 In early 2022, a herpesvirus was reported from Europe in captive Indian ringneck parrots and Alexandrine parakeets ( Psittacula eupatria ) with respiratory disease; partial DNA-dependent DNA polymerase sequences (GenBank OK665682–4) were identical to the viruses from the USA Bourke’s parrot PsAHV3 and Australian Indian ringneck PsAHV5 sequences. 3 The name “Psittacid herpesvirus 3” had previously also been used in GenBank not only with the Brazilian Indian ringneck parrot virus but also what was reported as PsAHV1 genotype 3.…”