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

Abstract

The first two European outbreaks of herpetic pneumonia caused by Psittacid alphaherpesvirus-5 were diagnosed based on gross pathology findings, histological examination, transmission electron microscopy visualization and genome sequencing. The outbreaks, characterized by high morbidity and high mortality rates, involved two parrot species, namely the Indian ringneck parrot (Psittacula krameri) and the Alexandrine parakeet (Psittacula eupatria). Clinical signs observed were ruffled feathers, dyspnea, tail bobbing, open wings while breathing, depression and anorexia. Necropsy was performed on Indian ringneck parrots only, and the most evident and serious gross lesion found in all the birds was a diffuse marked consolidation of the lungs associated with parenchyma congestion and oedema. Histological examination confirmed the existence of bronchopneumonia characterized by the presence of syncytial cells with intranuclear inclusion bodies. In one bird, fibrinous airsacculitis was observed as well. Lung tissue inspection through electron microscopy revealed the presence of virus particles resembling herpesviruses. Viral DNA was extracted, amplified using primers for Alloherpesviridae DNA polymerase gene detection, and then sequenced. BLAST analysis showed a 100% identity with the only previously reported sequence of PsHV-5 (MK955929.1).

A Survey of Diseases in Different Species of Wild, Captive, and Illegally Traded Birds in Brazil

“…A novel Psittacid herpesvirus in collared parakeets ( Psittacula krameri ) caused death in exotic birds in private captivity. In psittacines, Psittacid alphaherpesvirus 3 [ 27 ] and Psittacid alphaherpesvirus 5 [ 28 , 29 ] have been reported as the causative agents of respiratory disease. Birds such as the Bourke’s parakeet ( Neopsephotus bourkii ) in the United States [ 30 ], the Eclectus parrot ( Eclectus roratus ) in Australia [ 27 ], and the rose-ringed parakeet ( Psittacula krameri ) in Brazil [ 8 ] have been diagnosed with respiratory lesions caused by this virus.…”

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

“…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).…”

“…8,12 PsAHV-3 in parrots has been reported in the United States, 11 Australia, 4 and southern Brazil 9 ; these parrots had pneumonia with syncytial cells containing INIBs in the respiratory epithelium, and PsAHV-3 was detected by PCR analysis of lung tissues. A novel pathogenic virus, PsAHV-5, has been described in Australia, 13 Italy, 1 Brazil, 3 and the United States in Indian ringneck parakeets (syn. rose-ringed parakeet; Psittacula krameri ).…”

Psittacid alphaherpesvirus 5 infection in Indian ringneck parakeets in southern California

“… 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. The genetic distances among the PsAHV1 genotypes are more consistent with interspecies differences than intraspecies differences, suggesting that PsAHV1 may be divided in the future.…”