National Rabbit Biocontrol Optimisation


Rabbit biocontrol has had dramatic and widespread benefits to Australian agriculture and environment for 60 years, with benefits estimated at over $70 billion. For 20 years only one type of virulent RHDV has been circulating in Australia, to which some populations of rabbits started to develop genetic resistance. Since 2014, with the detection of two exotic virulent RHDVs, and the coordinated release of the RHDV1 K5 strain, there are now four virulent strains of RHDV present in Australia’s rabbit population. This increasing genetic diversity poses challenges as well as opportunities.  

Unfortunately, there is never likely to be a silver bullet in rabbit management. We know from monitoring studies that the best response is an ongoing one, ensuring that new rabbit biocontrol agents can be released on a regular basis to counteract reduced effectiveness of existing agents due to increasing immunity and genetic resistance. In addition, boosts to existing controls add to their effectiveness, particularly through a horses-for-courses type approach. As such, rabbit management is not about one-off applications of solutions but regular, community-based approaches drawing from a pipeline of new, existing and evolving solutions.




  1. A strengthened pipeline of new rabbit biocontrols from within Australia and internationally. 
  2. Best practice for where and when to apply which strain to maximise viral genetic diversity, based on best science determining what defines success of a virulent field strain.  
  3. Assessment of a more cost-effective landscape scale rabbit disease tracking tool to support the long-term goals and pipeline solutions approach of farmers to managing the impacts of rabbits.  
  4. Assess the feasibility of insect vector sampling as an additional more cost-effective tool for landscape scale tracking of rabbit disease activity. 
  • Determine diversity and distribution of RHDVs and which viral genes account for high levels of virulence and successful transmission in the field using genetic and functional studies of viral recombinants, which will inform the selection of possible future RHDV products (note development of a new product is not part of this proposal and functional studies of recombinants will depend on obtaining a PhD project for this aspect).  

Project Leader

Dr Tanja Strive (Biocontrol Domain)
Project Team
  • Dr Tanja Strive, CSIRO 
  • Dr Robyn Hall, CSIRO 
  • Ms Nina Huang, CSIRO 
  • Dr Sahra McFetridge, PIRSA
  • Dr Kandarp Patel, PIRSA
  • Dr Pat Taggart, NSWDPI
  • Dr Brad Page, PIRSA 
  • Dr Carlo Pacioni, Arthur Rylah Institute (ARI), Victoria
  • Dr David Ramsey, Arthur Rylah Institute (ARI), Victoria
  • Ridma Jayasinghe, PIRSA
  • Dr Bhumi Savaliya, PIRSA
Project Partners
  • Commonwealth Scientific and Industrial Research Organisation (CSIRO)
  • NSW Department of Primary Industries (NSW DPI)
  • Primary Industries and Region South Australia (PIRSA)
  • Meat and Livestock Australia (MLA)
  • Australian Wool Innovation (AWI)

The project receives funding from the Australian Government Department of Agriculture, Water and the Environment


Note: If you are a vet or domestic rabbit pet owner you can now submit samples directly for testing via this CSIRO portal – (follow the prompts)

February 2021 update:

Community submission of rabbit samples continues to deliver valuable insights into the changing epidemiology of the various circulating virus strains in Australia. Derivatives of the original Australian RHDV2 continues to be dominant in WA, while various recombinant RHDV2 variants are dominant throughout the Eastern states.

Analysis of sequence data provided strong evidence of RHDV1 activity inhibition as a result of initial RHDV2 spread, strengthening previous evidence derived from serological data that RHDV2 suppressed the impact of RHDV1-K5 when it was released in 2017.

August 2020 update:

RHDV2 and its recombinants continue to be epidemiologically dominant in the Australian landscape, however we are seeing growing evidence of some local persistence and spread of RHDV1-K5 in Western Australia and Tasmania, and the detection of an RHDV1 field strain demonstrates that this original virus variant has not yet become completely extinct.

RHDV2 causes virus outbreaks and transmission to occur approximately one season earlier than RHDV1. The ability to infect younger rabbits may be a key competitive advantage for RHDV2 in the field, consequently altering the epidemiology of the virus in wild populations of rabbits.

February 2020 update:

While RHDV2 remains the dominant virus circulating in the field in all areas of Australia, several cases of RHDV1 K5 have been detected one location that were not associated with a targeted release. These results suggest that RHDV1 K5 may have become established in wild rabbit populations in some locations. Further monitoring will be carried out through the project to better understand if this has occurred more widely or remains the exception.

CSIRO has developed a new assay for high throughput screening of recombinant caliciviruses. This assay has now been adopted into the routine testing protocols for RabbitScan and has retrospectively been applied to all positive calicivirus samples to confirm the identity of each sample.

A pilot study investigating the suitability of using carrion feeding flies as a better broad scale tool to monitor disease activity at a landscape scale is nearing completion of its first year. Preliminary analysis of the first nine months of samples (March 2019 to January 2020) indicate that RHDV activity can indeed be detected in fly samples, but the sensitivity of this method remains unclear at this stage. The aim is to continue this study for an additional 12 months to get a better understanding of this tool to monitor RHDV activity at a wider scale.

August 2019 update:

Ongoing testing of tissue from deceased rabbits shows RHDV2 remains the dominant rabbit calicivirus circulating in Australia, with K5 detected at release sites. A new screening method is being implemented to detect recombinant viruses.

Rabbit monitoring at selected intensive sites in TAS, ACT, WA, NSW and SA is ongoing or ramping up shortly, with a minimum bi-annual sampling taking place. In addition, monitoring and sampling of the rabbit population at the Turretfield research site continues as part of this project, building on extensive knowledge of this wild rabbit population and adding these ongoing monitoring results to the long-term RHDV and myxoma disease database at this site.

A paper on optimising and validating molecular testing of carrion flies for rabbit calicivirus detection, including associated protocols was published. This provided the basis for a nationwide year-long pilot study now underway.

February 2019 update: 

Intensive rabbit monitoring sites have been established with monitoring well underway at sites in South Australia and the ACT, and due to commence at other sites in Autumn 2019. Sites in South Australia are reporting the lowest abundance of rabbits in more than 20 years, indicating that circulating strains of RHDV are suppressing rabbit numbers. 

The methods for sampling, processing and analysing carrion feeding flies for the presence of RHDV have been developed and validated. A national fly monitoring network at over 30 sites across Australia has been established and fortnightly sampling has commenced.  

Analysis of samples from dead rabbits submitted directly to CSIRO and through RabbitScan is ongoing – over 1600 samples have been analysed since the beginning of the previous IA-CRC project RHD Boost Rollout, and ~1000 since the K5 release).  


Scientific publications:

  • Mahar, JE, Jenckel, M, Huang, N, Smertina, E, Holmes, EC, Stive, T, Hall, R. (2021) (submitted) Frequent intergenotypic recombination between the two non-structural genes is a major driver of epidemiological fitness in calicivirus. (
  • Kerr P.J., Hall R.N., Strive T. (2021) Viruses for Landscape-Scale Therapy: Biological Control of Rabbits in Australia. In: Lucas A.R. (eds) Viruses as Therapeutics. Methods in Molecular Biology, vol 2225. Humana, New York, NY.
  • Jenckel M, Hall R, Strive T (2022) Pathogen profiling of Australian rabbits by metatranscriptomic sequencing
  • Elfekih, S., Metcalfe, S., Walsh, T., Cox, T. and Strive, T. (2021), Genomic insights into a population of introduced European rabbits Oryctolagus cuniculus in Australia and the development of genetic resistance to Rabbit Hemorrhagic Disease virus (RHDV). Transboundary and Emerging Diseases. Accepted Author Manuscript.
  • Taggart PL, Hall RN, Cox TE, Kovaliski J, McLeod SR and Strive T (2022) ‘Changes in virus transmission dynamics following the emergence of RHDV2 shed light on its competitive advantage over previously circulating variants’, Transbound Emerg Dis, 69:1118–1130,
  • Ramsey, D., Cox, T., Strive, T., Forsyth, D., Stuart, I., Hall, R., Elsworth, P., Campbell, S. (2019). Emerging RHDV2 suppresses the impact of endemic and novel strains of RHDV on wild rabbit populations. Journal of Applied Ecology, 57(3), 630-641
  • Strive, T., Piper, M., Huang, N., Mourant, R., Kovaliski, J., Capucci, L., Cox, T., Smith, I. (2020). Retrospective serological analysis reveals presence of the emerging lagovirus RHDV2 in Australia in wild rabbits at least five months prior to its first detection. Transboundary and Emerging Diseases, 67(2), 822-833.
  • Cox, T. E., Ramsey, D. S., Sawyers, E., Campbell, S., Matthews, J., & Elsworth, P. (2019). The impact of RHDV-K5 on rabbit populations in Australia: an evaluation of citizen science surveys to monitor rabbit abundance. Scientific reports9(1), 1-11.
  • Hall, R. N., Huang, N., Roberts, J., & Strive, T. (2019). Carrion flies as sentinels for monitoring lagovirus activity in Australia. Transboundary and emerging diseases66(5), 2025-2032.
  • Strive, T., & Cox, T. E. (2019). Lethal biological control of rabbits–the most powerful tools for landscape-scale mitigation of rabbit impacts in Australia. Australian Zoologist40(1), 118-128.
  • Pacioni C, Hall RN, Strive T, Ramsey DSL, Gilland M and Vaughan TG (2022) ‘Comparative epidemiology of rabbit haemorrhagic disease virus strains from viral sequence data’. Viruses, 15(1): 21