>>Ms. Marguerite Wegner has recently written to Promed, concerned about the release of Rabbit haemorrhagic disease (RHDV) in Australia. This virus is also called Viral haemmoraghic disease of rabbits (VHD) and Rabbit calicivirus (RCV).
++The Australian Government adopted the name "Rabbit Calicivirus Disease" or "the Rabbit Calicivirus" as a local name for RHDV to be less emotive. The use of the name RCD/RCV instead of RHDV is incorrect and has been queeried by international scientists and researchers all around the world (Marguerite)
>>As one of the people heavily involved in the study into the human health effects of this virus in Australia, I felt compelled to respond. Her concern seems to be a belief that RHDV will spread from rabbits into other animals, particularly humans. There is no evidence that this can occur.
++No-one has ever gone looking for data to see if RHDV has caused ill health in different animal species on a global scale. Also, "no evidence of" should NEVER be used as "evidence" that something may not or will not occur. This is poor science. There is scientific evidence that RHDV can spread to other animals. Scientific literature has indicated that Hares have been infected by RHDV and Hares are a different Genus to rabbits. Also, according to the BRS Report 1996 on RCD, several animal species were deemed "positive" to RHDV after being deliberately injected with low doses of RHDV (their antibody reactivity was well above the cut-off level for the experiment thus they were deemed "positive" to RHDV).(Marguerite)
>>As she mentioned, RHDV spread throughout Asia and Europe, coming into contact with hundreds of humans in rabbitries along the way. There are no reports of anyone getting sick as a result of that contact, either anecdotally or in responses actively sought by us from 47 overseas laboratories working with this virus in 16 countries.
++Antibodies to RHDV were reported in a Mexican laboratory worker and lack of reports of people becoming sick from RHDV is a very weak basis on which to make any assumptions. There is no-one collecting and collating illnesses in people who work with rabbits on a global scale over time that I know of. I rescue and rehome rabbits and have suffered mystery illnesses ranging from a rash that lasted weeks to unknown illnesses which no doctor offered to investigate including an internal pain and fever that lasted over a week. No-one has asked for blood samples from myself. I have read the reponses from the laboratories received by the Human Health Study and some of them were poor answers invluding answers that showed that some laboratories contacted had not worked with the RHDV virus at all " (Marguerite)
++No human has been deliberately infected with RHDV to see if they will suffer the disease and my offer to the Australian government to be a human test subject was not even acknowledged (at least the newspaper here had a good story "I'll take virus-woman" was the front page lead article in a West Australian newspaper. ) (Marguerite)
>>Moreover, tests on a great number of other animal species, both here and overseas have yielded no infections in any animals other than lagomorphs.
++This is word play. Australian tests showed antibody levels over the cut-off level in many of these tests , technically being a "positive" reaction to RHDV in several species. In the 1996 BRS Report on RHDV(RCD) it was noted that several different species tested positive to RHDV including mice, bush rats, brown falcons, ferrets, pigeons, Silver gulls, Northern brown bandicoots, one wombat, all four echidnas, and one but probably all seven short-tailed bats developed an antibody response following rabbit hemorrhagic disease injection. (Marguerite)
>>Given this information, the virus was considered as a means of containing wild rabbits in Australia. They are generally regarded here as an environmental curse. Introduced here over 100 years ago, they have burrowed and eaten their way across much of Australia, aiding desertification, erosion and assisting in the demise of many native species of plants and animals. This is why the events in Australia are different to the cases in the other countries that Ms. Wegner mentioned, where extensive and expensive eradication programs were undertaken. In those countries, rabbits tend to be part of the natural landscape and are also farmed. There, rabbits were a resource under threat from a virus. Here, rabbits threaten our resources and may be contained by a virus.
++This is personal comment by Judy Carman. Rabbits were introduced to Australia by the white European settler and wild rabbits were a resource prior to the escape of RHDV onto the Australian mainland in 1996. Rabbit shooters and their families relied heavily on rabbits as source of income and Outback Foods had a market of millions of dollars for wild game rabbits. Akubra hats also preferred the wild rabbit fur to that of farmed rabbits. Also, in Western Australia, wild rabbits were not considered a problem. Ms Carman fails to address the terrible destruction to the Australian landscape due to introduced farmed hard hoofed farm animals (sheep, cattle etc) and the destruction of habitat on a wide scale that is still occurring from Australia's number one vertebrate pest - the white European settler. Focusing on purely the introduced wild rabbit as a source of all ills is very misleading (especially since Myxomatosis kills large numbers of wild rabbits in an ongoing holocaust.There may be at least 200 strains of Myxomatosis in the Australian wild according to NSW researchers.) (Marguerite)
>>When the virus escaped from field testing on an island off of the mainland, eradication attempts were undertaken to remove the virus from the mainland and to re-contain it on the island. However, within two weeks, and before this could happen, the virus then jumped 300 kilometers to north east, making eradication attempts costly and ultimately futile. It continued its spread and hit most of the rabbit-containing areas in Australia within months. Within some areas, however, the virus is spreading more slowly, possibly due to seasonal factors, including the availability of certain vectors at certain times of the year. Nevertheless, on the whole, the position seems to be the opposite to Ms. Wegner's assertion that the virus doesn't seem to be spreading well in Australia.
++It is scandelous that there were no prosecutions resulting from the escape of RHDV from containment on Wardang Island. The people in charge of this experiment must have known that the RHDV had already jumped the English Channel and yet they placed the RHDV virus out in the open on an island only 4 kilometres from the Australian mainland. There are still conflicting reports of RHDV in different parts of Australia. The wild rabbit has not been wiped out and some populations of wild rabbits seem to have immunity. Based on overseas experience, the RHDV will probably follow a cyclical pattern as less immune populations of wild rabbits become infected by RHDV every few years. (Marguerite)
>>There are also reports that as a result of the virus' work, in large areas, plants and animals not seen for many years are coming back, and the feral cat population has also crashed as a result of fewer rabbits to eat.
++There have also been reports of humans feeling unwell when the RHDV virus went through some areas and reports of gastroenteritis in some areas . There have also been reports of native animals dying along side the rabbits in some areas when the RHDV virus went through. Is there a word for extremists who value plant life above animal life to the extent that they will support germ warfare? (Marguerite)
>>A study into the potential human health effects of this virus has been undertaken. This ocurred because the Federal Government was unwilling to officially release the virus without greater evidence of the lack of infectivity in humans. That is, it was not willing to rely on the existing evidence, but wished to do a properly-conducted epidemiological study and serological survey to determine whether the virus could in fact infect humans.
++The world's best international calicivirus scientists and many virologists spoke out against the use of RHDV as a biological control agent. In my opinion, the Australian Government was trying to save face by conducting a "study" of human health. No person was ever injected with RHDV to see if infection occured. The Human Health study was a poorly constructed study based on questionaires and blood tests (except for some who did not have blood samples taken) of "exposed" vs non-exposed people. The basic data from these tests was examined by virologists overseas who came to different conclusions about the importance of this tiny test of only a few hundred people (a poor statistical sample indeed upon which to base any grand statements about what a disease will and will not do). ..(Marguerite)
>>Because of the virus's escape, we were able to find 153 people with exposure to RHDV, matched roughly to 116 controls with no exposure to the virus. Of those exposed, 108 had high exposure to the virus, including skinning or cutting-open infected rabbits with bare hands when they had open wounds or sores on their hands. There was no serological evidence of infection in any of the exposed or unexposed blood samples. In fact, in this study TWO different antibody tests were used, and these tests were first validated with a panel of 1013 RHDV-specific antibody negative sera, including ones with antibodies to the human caliciviruses hepatitis E and Norwalk-like viruses. We also asked questions about 26 symptoms that might be expected to result from infection with this virus in humans, including gastrointestinal illness, flu-like illness, rashes, hepatic illness, bleeding/clotting disorders and neurological symptoms. After a variety of different analyses, we found no evidence whatsoever that this virus could cause illness in humans.
++(Marguerite) For a better discussion of the human health data go to ....
Emerging Infectious Diseases Volume 4 Number 1 January - March 1998
>>Ms. Wegner has a copy of the human results that we produced for the Federal Government. We are currently writing these results for a peer-reviewed journal. Ms. Wegner is worried that there are no safe vaccines for humans and other animals from RHDV. Given the results above, she appears to be a member of a tiny minority who still believe that they are required.
++Not such a "tiny minority" see... (Marguerite)
Scientists who speak out against RHDV as a biocontrol
---Dr. Judy Carman
Senior EpidemiologistCommunicable Disease Control Branch
South Australian Health CommissionEmail firstname.lastname@example.org
Rabbit Information Service
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