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Rabbit haemorrhagic disease: virus persistence and adaptation in Australia.

Schwensow NI, Cooke B, Kovaliski J, Sinclair R, Peacock D, Fickel J, Sommer S - Evol Appl (2014)

Bottom Line: Together, these data suggest that RHDV survives in the Australian environment through its ability to spread amongst rabbit subpopulations.This is consistent with modelling results that indicated that in a large interconnected rabbit meta-population, RHDV should maintain high virulence, cause short, strong disease outbreaks but show low persistence in any given subpopulation.This new epidemiological framework is important for understanding virus-host co-evolution and future disease management options of pest species to secure Australia's remaining natural biodiversity.

View Article: PubMed Central - PubMed

Affiliation: Department of Evolutionary Genetics, Leibniz Institute for Zoo and Wildlife Research (IZW) Berlin, Germany ; School of Earth and Environmental Sciences, University of Adelaide Adelaide, SA, Australia.

ABSTRACT
In Australia, the rabbit haemorrhagic disease virus (RHDV) has been used since 1996 to reduce numbers of introduced European rabbits (Oryctolagus cuniculus) which have a devastating impact on the native Australian environment. RHDV causes regular, short disease outbreaks, but little is known about how the virus persists and survives between epidemics. We examined the initial spread of RHDV to show that even upon its initial spread, the virus circulated continuously on a regional scale rather than persisting at a local population level and that Australian rabbit populations are highly interconnected by virus-carrying flying vectors. Sequencing data obtained from a single rabbit population showed that the viruses that caused an epidemic each year seldom bore close genetic resemblance to those present in previous years. Together, these data suggest that RHDV survives in the Australian environment through its ability to spread amongst rabbit subpopulations. This is consistent with modelling results that indicated that in a large interconnected rabbit meta-population, RHDV should maintain high virulence, cause short, strong disease outbreaks but show low persistence in any given subpopulation. This new epidemiological framework is important for understanding virus-host co-evolution and future disease management options of pest species to secure Australia's remaining natural biodiversity.

No MeSH data available.


Related in: MedlinePlus

ML tree of rabbit haemorrhagic disease virus (RHDV) sequences (GenBank accession numbers) obtained from rabbits found dead at the Turretfield site (South Australia) between 1999 and 2011. Most variants cluster according to the year. The tree was rooted with the Australian RHDV inoculums strain that was manufactured from Czech CAPM-V351. It has been used since 1996 for biocontrol purpose and was in the same year deliberately released in the Turretfield population. Later, blood analyses showed, however, that the Turretfield population had already experienced a previous virus contact (most likely in 1995 when the virus escaped from an experimental site on Wardang Island, South Australia). Numbers at nodes represent bootstrap support (1000 iterations).
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fig04: ML tree of rabbit haemorrhagic disease virus (RHDV) sequences (GenBank accession numbers) obtained from rabbits found dead at the Turretfield site (South Australia) between 1999 and 2011. Most variants cluster according to the year. The tree was rooted with the Australian RHDV inoculums strain that was manufactured from Czech CAPM-V351. It has been used since 1996 for biocontrol purpose and was in the same year deliberately released in the Turretfield population. Later, blood analyses showed, however, that the Turretfield population had already experienced a previous virus contact (most likely in 1995 when the virus escaped from an experimental site on Wardang Island, South Australia). Numbers at nodes represent bootstrap support (1000 iterations).

Mentions: PCR confirmed the presence of RHDV RNA in 58 of the 63 samples available from dead rabbits collected at Turretfield. There was no evidence that individual rabbits had been infected by more than one virus variant. We identified 24 different RHDV sequences with 2–4 variants per year (Table2, for GenBank accession numbers: see Fig.4). The average number of nucleotide differences among RHDV variants obtained from the same year was 4.21 ± SE 4.45 (=0.9%). However, sequences from the years 1999 and 2011 showed a higher degree of variability than sequences in other years. Sequences isolated from rabbits that died in a given year clustered together (Fig.4). Exceptions were sequences from 1999, which were more diverse, and because of low bootstrap values, their phylogenetic position could not be resolved with confidence to be sure of their exact position in the dendrogram.


Rabbit haemorrhagic disease: virus persistence and adaptation in Australia.

Schwensow NI, Cooke B, Kovaliski J, Sinclair R, Peacock D, Fickel J, Sommer S - Evol Appl (2014)

ML tree of rabbit haemorrhagic disease virus (RHDV) sequences (GenBank accession numbers) obtained from rabbits found dead at the Turretfield site (South Australia) between 1999 and 2011. Most variants cluster according to the year. The tree was rooted with the Australian RHDV inoculums strain that was manufactured from Czech CAPM-V351. It has been used since 1996 for biocontrol purpose and was in the same year deliberately released in the Turretfield population. Later, blood analyses showed, however, that the Turretfield population had already experienced a previous virus contact (most likely in 1995 when the virus escaped from an experimental site on Wardang Island, South Australia). Numbers at nodes represent bootstrap support (1000 iterations).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4231595&req=5

fig04: ML tree of rabbit haemorrhagic disease virus (RHDV) sequences (GenBank accession numbers) obtained from rabbits found dead at the Turretfield site (South Australia) between 1999 and 2011. Most variants cluster according to the year. The tree was rooted with the Australian RHDV inoculums strain that was manufactured from Czech CAPM-V351. It has been used since 1996 for biocontrol purpose and was in the same year deliberately released in the Turretfield population. Later, blood analyses showed, however, that the Turretfield population had already experienced a previous virus contact (most likely in 1995 when the virus escaped from an experimental site on Wardang Island, South Australia). Numbers at nodes represent bootstrap support (1000 iterations).
Mentions: PCR confirmed the presence of RHDV RNA in 58 of the 63 samples available from dead rabbits collected at Turretfield. There was no evidence that individual rabbits had been infected by more than one virus variant. We identified 24 different RHDV sequences with 2–4 variants per year (Table2, for GenBank accession numbers: see Fig.4). The average number of nucleotide differences among RHDV variants obtained from the same year was 4.21 ± SE 4.45 (=0.9%). However, sequences from the years 1999 and 2011 showed a higher degree of variability than sequences in other years. Sequences isolated from rabbits that died in a given year clustered together (Fig.4). Exceptions were sequences from 1999, which were more diverse, and because of low bootstrap values, their phylogenetic position could not be resolved with confidence to be sure of their exact position in the dendrogram.

Bottom Line: Together, these data suggest that RHDV survives in the Australian environment through its ability to spread amongst rabbit subpopulations.This is consistent with modelling results that indicated that in a large interconnected rabbit meta-population, RHDV should maintain high virulence, cause short, strong disease outbreaks but show low persistence in any given subpopulation.This new epidemiological framework is important for understanding virus-host co-evolution and future disease management options of pest species to secure Australia's remaining natural biodiversity.

View Article: PubMed Central - PubMed

Affiliation: Department of Evolutionary Genetics, Leibniz Institute for Zoo and Wildlife Research (IZW) Berlin, Germany ; School of Earth and Environmental Sciences, University of Adelaide Adelaide, SA, Australia.

ABSTRACT
In Australia, the rabbit haemorrhagic disease virus (RHDV) has been used since 1996 to reduce numbers of introduced European rabbits (Oryctolagus cuniculus) which have a devastating impact on the native Australian environment. RHDV causes regular, short disease outbreaks, but little is known about how the virus persists and survives between epidemics. We examined the initial spread of RHDV to show that even upon its initial spread, the virus circulated continuously on a regional scale rather than persisting at a local population level and that Australian rabbit populations are highly interconnected by virus-carrying flying vectors. Sequencing data obtained from a single rabbit population showed that the viruses that caused an epidemic each year seldom bore close genetic resemblance to those present in previous years. Together, these data suggest that RHDV survives in the Australian environment through its ability to spread amongst rabbit subpopulations. This is consistent with modelling results that indicated that in a large interconnected rabbit meta-population, RHDV should maintain high virulence, cause short, strong disease outbreaks but show low persistence in any given subpopulation. This new epidemiological framework is important for understanding virus-host co-evolution and future disease management options of pest species to secure Australia's remaining natural biodiversity.

No MeSH data available.


Related in: MedlinePlus