Isolation of chicken anaemia virus from broiler chickens in New Zealand

Stanislawek, W. L.; Howell, Joseph M.

doi:10.1080/00480169.1994.35787

Cited by 10 publications

(5 citation statements)

References 10 publications

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“…Anaemia is a common finding in most reports of birds infected with CAV at 1 day of age, with the PCV reduced between 7 and 14 days after infection (Connor et al, 1991;Imai et al, 1999;von Bulow & Fuchs, 1986). However, there are reports of outbreaks of disease due to CAV in flocks with typical lesions in lymphoid tissues, but no signs of anaemia (Stanislawek & Howell, 1994). As anaemia in birds infected at 1 day of age is transient, it is possible that the lack of anaemia in infected birds in our study was due to the 14 day time interval between infection and sampling.…”

Section: Discussionmentioning

confidence: 74%

“…A haematocrit less than 27 %, and typically between 9 and 23 %, is found at 7-14 days post-infection for chicks infected at 1 day of age (normal 32-37.5 %) (Connor et al, 1991;Imai et al, 1999;von Bulow & Fuchs, 1986). Reports of confirmed outbreaks of CAV in five flocks in New Zealand described the presence of typical CAV-induced lesions in lymphoid tissues, but no changes were observed in the haematocrit (Stanislawek & Howell, 1994). These reports indicate that anaemia is not always found in field CAV infections.…”

Section: Infection With Viruses Mutated In Vp2mentioning

confidence: 68%

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Attenuation of chicken anemia virus by site-directed mutagenesis of VP2

Peters

Crabb

Tivendale

et al. 2007

Journal of General Virology

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Chicken anemia virus (CAV) is a significant immunosuppressive pathogen of chickens, but relatively little is known about the effect of specific mutations on its virulence. In order to study the virulence of CAV, an infection model was developed in embryos. Significant growth depression, measured as a reduction in mean body weight, was found for wild-type CAV infection. Infection with wild-type CAV resulted in a significant reduction in thymic and splenic weights and consistently produced severe lesions in the thymus, spleen and bone marrow, as well as haemorrhages. CAVs mutated in the VP2 gene were infectious for embryos, but were highly attenuated with respect to growth depression and CAV-specific pathology. Relative to wild-type infection, viruses Mut C86R, Mut R101G, Mut H103Y, Mut R129G, Mut Q131P, Mut R/K/K150/ 151/152G/A/A, Mut D/E161/162G/G and Mut E186G were highly attenuated, and viruses Mut L163P and Mut D169G were moderately attenuated. Attenuation of the ability to produce lesions was found consistently for the thymus, spleen and bone marrow, thymic and splenic weights, and for CAV-induced haemorrhage. There was no growth depression associated with infection by the group of highly attenuated mutant viruses and a moderate reduction in mean body weight was only found for virus Mut L163P. These findings show that mutations in the VP2 gene can reduce the virulence of CAV and these mutant viruses may have value as vaccine candidates.

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Section: Discussionmentioning

confidence: 74%

Section: Infection With Viruses Mutated In Vp2mentioning

confidence: 68%

Attenuation of chicken anemia virus by site-directed mutagenesis of VP2

Peters

Crabb

Tivendale

et al. 2007

Journal of General Virology

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“…Other viruses within the genus Gyrovirus are known to infect avian species and cause similar pathology. In particular, Chicken anaemia virus (CAV) is a wellcharacterised pathogenic virus in the Anelloviridae causing anaemia, haemorrhage and immunosuppression in poultry chicks, inflicting significant economic losses to the industry (13,(22)(23)(24). CAV can be transmitted both horizontally and vertically and, as a small circular DNA virus, is highly stable and resistant to most disinfectants (13,(25)(26)(27).…”

Section: Discussionmentioning

confidence: 99%

A novel gyrovirus associated with a fatal respiratory disease in yellow-eyed penguin (Megadyptes antipodes) chicks

Wierenga

Morgan

Hunter

et al. 2022

Preprint

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Yellow-eyed penguins (Megadyptes antipodes), or hoiho in te reo Māori, are predicted to become extinct on mainland Aotearoa New Zealand in the next few decades, with infectious disease a significant contributor to their decline. A recent disease phenomenon termed respiratory distress syndrome (RDS) causing lung pathology has been identified in very young chicks. To date, no causative pathogens for RDS have been identified. In 2020 and 2021, the number of chick deaths from suspected RDS increased four- and five-fold, respectively, with a mortality rate of >90%. Here, we aimed to identify possible pathogens responsible for RDS disease impacting yelloweyed penguins. Total RNA was extracted from tissue samples collected during post-mortem of 43 chicks and subject to metatranscriptomic sequencing. From these data we identified a novel and highly abundant gyrovirus in 80% of tissue samples. This virus exhibited only 41% amino acid identity within VP1 to its closest relative, Gyrovirus 8, discovered in a diseased seabird. No other exogenous viral transcripts, nor pathogenic bacterial, protozoal and fungal organisms, were identified in these tissues. Due to the high relative abundance of viral reads, it is likely that this novel gyrovirus is associated with RDS in yellow-eyed penguin chicks.Author SummaryNew Zealand’s population of yellow-eyed penguins, also called hoiho, are predicted to become extinct in the next 20-30 years, with disease a major factor contributing to their decline. A new disease, causing fluid and bleeding into the lungs, was initially identified in 2019 in very young chicks. It was characterised as causing respiratory distress with a mortality of >90% usually within the first week of life. To date, no causative pathogens of the disease have been identified. We aimed to identify possible pathogens responsible for respiratory disease in these penguin chicks. A metatranscriptomic survey of dead chicks identified a novel and highly abundant gyrovirus present in diseased tissue, with closely related viruses causing disease in other avian hosts. It is, therefore, highly likely that this novel gyrovirus is associated with respiratory disease in these chicks. This finding offers the potential to increase the success of disease management in the critically endangered yellow-eyed penguin and possibly other at-risk penguin species. The potential to lessen mortality and slow the decline of the species is essential in protecting the biodiversity of New Zealand’s fauna and flora.

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“…The disease is present in New Zealand (Julian & McKenzie, 1985) but the prevalence is unknown and it is not believed to be a major problem in this country. Chicken anaemia virus infection is also present in chickens in New Zealand and causes increased mortality, anaemia and atrophy of the lymphoid system, which is likely to predispose affected birds to secondary bacterial, viral and fungal infections (Stanislawek & Howell, 1994). Affected birds may have focal skin lesions characterized by discoloration, skin breakages and exudation (McNulty, 1991), but unlike PBFD, feather and beak abnormalities are not a feature.…”

Section: Discussionmentioning

confidence: 99%

Circovirus-like infection in a southern black-backed gull (Larus dominicanus)

Twentyman¹,

Alley²,

Meers³

et al. 1999

Avian Pathology

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A juvenile black-backed gull (Larus dominicanus) from the Manawatu region of New Zealand was found to have chronic airsacculitis due to Aspergillus spp. Histologically, there was moderately severe in¯ammation in the bursa of Fabricius associated with large, basophilic, intracytoplasmic inclusions, which ultrastructurally had an appearance typical of circovirus inclusions. This ® nding suggests that circoviruses may be more widespread in avian species than previously recognized and may be responsible for diseases associated with immunosuppression in free-living birds.

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Isolation of chicken anaemia virus from broiler chickens in New Zealand

Cited by 10 publications

References 10 publications

Attenuation of chicken anemia virus by site-directed mutagenesis of VP2

Attenuation of chicken anemia virus by site-directed mutagenesis of VP2

A novel gyrovirus associated with a fatal respiratory disease in yellow-eyed penguin (Megadyptes antipodes) chicks

Circovirus-like infection in a southern black-backed gull (Larus dominicanus)

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