scholarly journals A Potential Atypical Case of Rabbit Haemorrhagic Disease in a Dwarf Rabbit

Animals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 40
Author(s):  
Fábio A. Abade dos Santos ◽  
Carolina Magro ◽  
Carina L. Carvalho ◽  
Pedro Ruivo ◽  
Margarida D. Duarte ◽  
...  
Keyword(s):  
Clinical Signs ◽  
Myxoma Virus ◽  
European Rabbit ◽  
Rabbit Haemorrhagic Disease Virus ◽  
Structural Genes ◽  
Bivalent Vaccine ◽  
Rabbit Haemorrhagic Disease ◽  
Cross Immunity ◽  
Domestic Rabbits ◽  
Haemorrhagic Disease

Rabbit haemorrhagic disease (RHD) is a highly contagious infectious disease of European wild and domestic rabbits. Rabbit haemorrhagic disease virus (RHDV, GI.1) emerged in 1986 in Europe, rapidly spreading all over the world. Several genotypes of RHDV have been recognised over time, but in 2010, a new virus (RHDV2/RHDVb, GI.2) emerged and progressively replaced the previous RHDV strains, due to the lack of cross-immunity conferred between RHDV and RHDV2. RHDV2 has a high mutation rate, similarly to the other calivirus and recombines with strains of RHDV and non-pathogenic calicivirus (GI.4), ensuring the continuous emergence of new field strains. Although this poses a threat to the already endangered European rabbit species, the available vaccines against RHDV2 and the compliance of biosafety measures seem to be controlling the infection in the rabbit industry Pet rabbits, especially when kept indoor, are considered at lower risk of infections, although RHDV2 and myxoma virus (MYXV) constitute a permanent threat due to transmission via insects. Vaccination against these viruses is therefore recommended every 6 months (myxomatosis) or annually (rabbit haemorrhagic disease). The combined immunization for myxomatosis and RHDV through a commercially available bivalent vaccine with RHDV antigen has been extensively used (Nobivac® Myxo-RHD, MSD, Kenilworth, NJ, USA). This vaccine however does not confer proper protection against the RHDV2, thus the need for a rabbit clinical vaccination protocol update. Here we report a clinical case of hepatitis and alteration of coagulation in a pet rabbit that had been vaccinated with the commercially available bivalent vaccine against RHDV and tested positive to RHDV2 after death. The animal developed a prolonged and atypical disease, compatible with RHD. The virus was identified to be an RHDV2 recombinant strain, with the structural backbone of RHDV2 (GI.2) and the non-structural genes of non-pathogenic-A1 strains (RCV-A1, GI.4). Although confirmation of the etiological agent was only made after death, the clinical signs and analytic data were very suggestive of RHD.

scholarly journals Novel Trivalent Vectored Vaccine for Control of Myxomatosis and Disease Caused by Classical and a New Genotype of Rabbit Haemorrhagic Disease Virus

Vaccines ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 441 ◽  
Author(s):  
Sylvia Reemers ◽  
Leon Peeters ◽  
Joyce van Schijndel ◽  
Beth Bruton ◽  
David Sutton ◽  
...  
Keyword(s):  
Disease Virus ◽  
Myxoma Virus ◽  
European Rabbit ◽  
Viral Diseases ◽  
Serological Response ◽  
Rabbit Haemorrhagic Disease Virus ◽  
Rabbit Haemorrhagic Disease ◽  
New Genotype ◽  
Vectored Vaccine ◽  
Haemorrhagic Disease

Myxoma virus (MV) and rabbit haemorrhagic disease virus (RHDV) are the major causes of lethal viral diseases in the European rabbit. In 2010, a new RHDV genotype (RHDV2) emerged in the field that had limited cross-protection with the classical RHDV (RHDV1). For optimal protection of rabbits and preventing spread of disease, a vaccine providing protection against all three key viruses would be ideal. Therefore, a novel trivalent myxoma vectored RHDV vaccine (Nobivac Myxo-RHD PLUS) was developed similar to the existing bivalent myxoma vectored RHDV vaccine Nobivac Myxo-RHD. The new vaccine contains the Myxo-RHDV1 strain already included in Nobivac Myxo-RHD and a similarly produced Myxo-RHDV2 strain. This paper describes several key safety and efficacy studies conducted for European licensing purposes. Nobivac Myxo-RHD PLUS showed to be safe for use in rabbits from five weeks of age onwards, including pregnant rabbits, and did not spread from vaccinated rabbits to in-contact controls. Furthermore, protection to RHDV1 and RHDV2 was demonstrated by challenge, while the serological response to MV was similar to that after vaccination with Nobivac Myxo-RHD. Therefore, routine vaccination with Nobivac Myxo-RHD PLUS can prevent the kept rabbit population from these major viral diseases.

Potential use of myxoma virus and rabbit haemorrhagic disease virus to control feral rabbits in the Kerguelen Archipelago

2004 ◽  
Vol 31 (4) ◽  
pp. 415 ◽  
Author(s):  
B. D. Cooke ◽  
J.-L. Chapuis ◽  
V. Magnet ◽  
A. Lucas ◽  
J. Kovaliski
Keyword(s):  
Disease Virus ◽  
Disease Transmission ◽  
Biological Control Agent ◽  
Myxoma Virus ◽  
European Rabbit ◽  
Rabbit Haemorrhagic Disease Virus ◽  
Rabbit Haemorrhagic Disease ◽  
Haemorrhagic Disease ◽  
Low Prevalence ◽  
Kerguelen Archipelago

Rabbits have caused enormous damage to the vegetation on seven islands in the sub-Antarctic Kerguelen archipelago, including the main island, Grande Terre. Rabbit sera collected during 2001–02 were tested for antibodies against myxoma virus and rabbit haemorrhagic disease virus with a view to considering the wider use of these viruses to control rabbits. The results confirmed work done 15–20 years earlier that suggested that myxoma virus has not spread across all parts of Grande Terre and occurs at low prevalence among rabbits. By contrast, on Ile du Cimetière, where European rabbit fleas were introduced in 1987–88, the prevalence of myxoma antibodies is high and the rabbit population is relatively low, supporting the idea that the fleas are effective vectors of myxoma virus. Consequently, there should be benefits in releasing fleas on Grand Terre to enhance disease transmission. Reactivity of some rabbit sera in RHD-specific ELISAs suggested that a virus similar to RHDV may be present at low prevalence on Grande Terre but most rabbits are likely to be susceptible and this virus could be considered for use as a future biological control agent.

Myxoma virus and rabbit haemorrhagic disease virus 2 coinfection in a European wild rabbit (Oryctolagus cuniculus algirus), Portugal

2020 ◽  
Vol 8 (1) ◽  
pp. e001002 ◽  
Author(s):  
Carina Luisa Carvalho ◽  
Fábio Alexandre Abade dos Santos ◽  
Teresa Fagulha ◽  
Paulo Carvalho ◽  
Paula Mendonça ◽  
...  
Keyword(s):  
Disease Virus ◽  
Oryctolagus Cuniculus ◽  
Rare Event ◽  
Myxoma Virus ◽  
European Rabbit ◽  
Wild Rabbit ◽  
Rabbit Haemorrhagic Disease Virus ◽  
Sample Collection ◽  
Rabbit Haemorrhagic Disease ◽  
Haemorrhagic Disease

Myxoma virus (MYXV) and rabbit haemorrhagic disease virus 2 (RHDV2) are two major pathogens that affect the European rabbit (Oryctolagus cuniculus). Between August 2017 and August 2019, 1166 wild rabbits (971 legally hunted and 195 found dead) were tested by PCR-based methods for MYXV and RHDV2 within the scope of an ongoing surveillance programme on wild leporids in Portugal. Despite never having been reported before and being considered a rare event, coinfection by RHDV2 and MYXV was detected in one juvenile wild rabbit found dead in the Évora district located in Alentejo. The relative frequency of coinfection in the group of diseased rabbits (found dead in the field) was 0.52 per cent (1/195). The positivity percentage of each single virus was much higher, namely, 14.36 per cent (28/195) for MYXV and 55.38 per cent (108/195) for RHDV2, within the 2 years of sample collection considered.

Lethal biological control of rabbits – the most powerful tools for landscape-scale mitigation of rabbit impacts in Australia

2019 ◽  
Vol 40 (1) ◽  
pp. 118-128 ◽  
Author(s):  
Tanja Strive ◽  
Tarnya E. Cox
Keyword(s):  
Population Control ◽  
Landscape Scale ◽  
Myxoma Virus ◽  
Effective Control ◽  
Rabbit Haemorrhagic Disease Virus ◽  
The Past ◽  
Rabbit Haemorrhagic Disease ◽  
Domestic Rabbits ◽  
Haemorrhagic Disease

ABSTRACT The viral biocontrol agents Myxoma virus (MYXV) and Rabbit Haemorrhagic Disease Virus (RHDV1), released in 1950 and 1996 respectively, are the only control tools to have resulted in significant and lasting landscape-scale suppression of rabbit populations in Australia. Multiple conservation benefits and significant economic savings have resulted from the long-term and widespread reductions in rabbit numbers and impacts. In an effort to ‘boost’ rabbit biocontrol, an additional variant of RHDV1 ('K5') was recently released nationwide to counteract the decreasing effectiveness of both RHDV1 and MYXV that results from the evolutionary ‘arms race’ between viruses and their hosts. Two years prior to the K5 release, an exotic RHDV strain (RHDV2) appeared in Australia. The commercially available vaccine used to protect pet and farmed rabbits against the officially released K5 was ineffective against the exotic RHDV2, resulting in numerous deaths of domestic rabbits. This created substantial confusion about which strain was released as a biocontrol tool, as well as renewed concerns amongst pet rabbit owners and rabbit farmers about the use of viruses as lethal rabbit control tools in general. Ongoing effective control of wild rabbits in Australia is absolutely essential to protect the substantial conservation gains made by the long-term suppression of rabbit numbers over the past decades, and there is currently no alternative population control tool to achieve this at the required landscape scale. Vaccine formulations need updating to protect non-target farmed and pet rabbits from circulating field variants, including RHDV2, and to increase public acceptance for the ongoing use of viral biocontrol for feral rabbit populations.

scholarly journals Immunogenicity in Rabbits of Virus-Like Particles from a Contemporary Rabbit Haemorrhagic Disease Virus Type 2 (GI.2/RHDV2/b) Isolated in The Netherlands

Viruses ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 553 ◽  
Author(s):  
Qiuhong Miao ◽  
Ruibing Qi ◽  
Luut Veldkamp ◽  
Jooske Ijzer ◽  
Marja L. Kik ◽  
...  
Keyword(s):  
The Netherlands ◽  
Disease Virus ◽  
Genome Sequence ◽  
Insect Cells ◽  
Rabbit Haemorrhagic Disease Virus ◽  
Virus Like Particles ◽  
Rabbit Haemorrhagic Disease ◽  
Domestic Rabbits ◽  
Haemorrhagic Disease

Rabbit haemorrhagic disease virus (RHDV) type 2 (GI.2/RHDV2/b) is an emerging pathogen in wild rabbits and in domestic rabbits vaccinated against RHDV (GI.1). Here we report the genome sequence of a contemporary RHDV2 isolate from the Netherlands and investigate the immunogenicity of virus-like particles (VLPs) produced in insect cells. RHDV2 RNA was isolated from the liver of a naturally infected wild rabbit and the complete viral genome sequence was assembled from sequenced RT-PCR products. Phylogenetic analysis based on the VP60 capsid gene demonstrated that the RHDV2 NL2016 isolate clustered with other contemporary RHDV2 strains. The VP60 gene was cloned in a baculovirus expression vector to produce VLPs in Sf9 insect cells. Density-gradient purified RHDV2 VLPs were visualized by transmission electron microscopy as spherical particles of around 30 nm in diameter with a morphology resembling authentic RHDV. Immunization of rabbits with RHDV2 VLPs resulted in high production of serum antibodies against VP60, and the production of cytokines (IFN-γ and IL-4) was significantly elevated in the immunized rabbits compared to the control group. The results demonstrate that the recombinant RHDV2 VLPs are highly immunogenic and may find applications in serological detection assays and might be further developed as a vaccine candidate to protect domestic rabbits against RHDV2 infection.

Should the 40-year-old practice of releasing virulent myxoma virus to control rabbits (Oryctolagus cuniculus) be continued?

2006 ◽  
Vol 33 (7) ◽  
pp. 549 ◽  
Author(s):  
D. Berman ◽  
P. J. Kerr ◽  
R. Stagg ◽  
B. H. van Leeuwen ◽  
T. Gonzalez
Keyword(s):  
Virulent Strain ◽  
Clinical Signs ◽  
Laboratory Strain ◽  
Myxoma Virus ◽  
South West ◽  
Rabbit Haemorrhagic Disease ◽  
Virulent Virus ◽  
Original Laboratory ◽  
The 1960S ◽  
Haemorrhagic Disease

Release of virulent myxoma virus has been a key component of rabbit-control operations in Queensland, Australia, since the 1960s but its use rests on anecdotal reports. During a routine operation to release virulent myxoma virus we found no evidence to support the continued regular use of the technique in south-west Queensland. Radio-tagged rabbits inoculated with virulent myxoma virus contracted the disease but failed to pass enough virus to other rabbits to spread the disease. Rabbits with clinical signs of myxomatosis that were shot were infected with field strain derived from the original laboratory strain released in 1950 rather than the virulent strain that has been released annually. There was no change in rabbit survival or abundance caused by the release. Nevertheless, the release of virulent virus may be useful against isolated pockets of rabbits mainly because field strains are less likely to be present. Such pockets are more common now that rabbit haemorrhagic disease virus is established in Queensland.

Seropositivity to rabbit haemorrhagic disease virus in non-target mammals during periods of viral activity in a population of wild rabbits in New Zealand

2006 ◽  
Vol 33 (4) ◽  
pp. 305 ◽  
Author(s):  
J. Henning ◽  
P. R. Davies ◽  
J. Meers
Keyword(s):  
New Zealand ◽  
Disease Virus ◽  
Small Sample ◽  
European Rabbit ◽  
Wild Rabbit ◽  
Rabbit Haemorrhagic Disease Virus ◽  
Target Species ◽  
Rabbit Population ◽  
Rabbit Haemorrhagic Disease ◽  
Haemorrhagic Disease

As part of a longitudinal study of the epidemiology of rabbit haemorrhagic disease virus (RHDV) in New Zealand, serum samples were obtained from trapped feral animals that may have consumed European rabbit (Oryctolagus cuniculus) carcasses (non-target species). During a 21-month period when RHDV infection was monitored in a defined wild rabbit population, 16 feral house cats (Felis catus), 11 stoats (Mustela erminea), four ferrets (Mustela furo) and 126 hedgehogs (Erinaceus europaeus) were incidentally captured in the rabbit traps. The proportions of samples that were seropositive to RHDV were 38% for cats, 18% for stoats, 25% for ferrets and 4% for hedgehogs. Seropositive non-target species were trapped in April 2000, in the absence of an overt epidemic of rabbit haemorrhagic disease (RHD) in the rabbit population, but evidence of recent infection in rabbits was shown. Seropositive non-target species were found up to 2.5 months before and 1 month after this RHDV activity in wild rabbits was detected. Seropositive predators were also trapped on the site between 1 and 4.5 months after a dramatic RHD epidemic in February 2001. This study has shown that high antibody titres can be found in non-target species when there is no overt evidence of RHDV infection in the rabbit population, although a temporal relationship could not be assessed statistically owning to the small sample sizes. Predators and scavengers might be able to contribute to localised spread of RHDV through their movements.

Temporal dynamics of rabbit haemorrhagic disease virus infection in a low-density population of wild rabbits (Oryctolagus cuniculus) in New Zealand

2006 ◽  
Vol 33 (4) ◽  
pp. 293 ◽  
Author(s):  
J. Henning ◽  
D. U. Pfeiffer ◽  
P. R. Davies ◽  
J. Meers ◽  
R. S. Morris
Keyword(s):  
New Zealand ◽  
Disease Virus ◽  
Oryctolagus Cuniculus ◽  
Temporal Dynamics ◽  
Population Decline ◽  
Adult Survivors ◽  
European Rabbit ◽  
Rabbit Haemorrhagic Disease Virus ◽  
Rabbit Haemorrhagic Disease ◽  
Haemorrhagic Disease

A longitudinal capture–mark–recapture study was conducted to determine the temporal dynamics of rabbit haemorrhagic disease (RHD) in a European rabbit (Oryctolagus cuniculus) population of low to moderate density on sand-hill country in the lower North Island of New Zealand. A combination of sampling (trapping and radio-tracking) and diagnostic (cELISA, PCR and isotype ELISA) methods was employed to obtain data weekly from May 1998 until June 2001. Although rabbit haemorrhagic disease virus (RHDV) infection was detected in the study population in all 3 years, disease epidemics were evident only in the late summer or autumn months in 1999 and 2001. Overall, 20% of 385 samples obtained from adult animals older than 11 weeks were seropositive. An RHD outbreak in 1999 contributed to an estimated population decline of 26%. A second RHD epidemic in February 2001 was associated with a population decline of 52% over the subsequent month. Following the outbreaks, the seroprevalence in adult survivors was between 40% and 50%. During 2000, no deaths from RHDV were confirmed and mortalities were predominantly attributed to predation. Influx of seronegative immigrants was greatest in the 1999 and 2001 breeding seasons, and preceded the RHD epidemics in those years. Our data suggest that RHD epidemics require the population immunity level to fall below a threshold where propagation of infection can be maintained through the population.

scholarly journals Apoptosis of peripheral blood leucocytes in rabbits infected with different strains of rabbit haemorrhagic disease virus.

2013 ◽  
Vol 60 (1) ◽  
Author(s):  
Paulina Niedźwiedzka-Rystwej ◽  
Beata Hukowska-Szematowicz ◽  
Beata Tokarz-Deptuła ◽  
Alicja Trzeciak-Ryczek ◽  
Joanna Działo ◽  
...  
Keyword(s):  
Disease Virus ◽  
Peripheral Blood ◽  
Host Immune System ◽  
Rabbit Haemorrhagic Disease Virus ◽  
Rabbit Haemorrhagic Disease ◽  
Domestic Rabbits ◽  
Different Strains ◽  
Haemorrhagic Disease ◽  
Peripheral Blood Leucocytes ◽  
Stimulation Of

The pathogenicity of RHDV (rabbit haemorrhagic disease virus) is mainly associated with its affinity to blood vessels, with causing disseminated intravascular coagulations (DIC), and with the stimulation of the host immune system. Moreover, there are implications suggesting that apoptosis may be a pivotal process in understanding the basis of viral haemorrhagic disease in rabbits - a serious infectious disease causing mortality to wild and domestic rabbits. The aim of this study is to evaluate, by means of flow cytometry, the dynamics of apoptosis in peripheral blood granulocytes and lymphocytes in rabbits experimentally infected with seven different strains of RHDV and so-called antigenic variants of RHDV denominated as RHDVa, i.e.: Hungarian 24V/89, 1447V/96, 72V/2003; Austrian 01-04, 237/04, V-412 and French 05-01. The results showed that all of the RHDV and RHDVa strains cause an increase in the number of apoptotic cells throughout the infection, which might indicate the need for further analysis of the importance of this process.

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