TIMARU -- "Venom" made by Mackenzie country farmers to spread rabbit calicivirus disease (RCD) has been found to have a low concentration of the virus. Agriculture Ministry (MAF) manager of corporate communications Debbie Gee said tests had shown RCD was present, but the liquid had to be tested for other diseases. Philip Mackay, one of the two Mackenzie country farmers who admitted to spreading the venom, said he was surprised to hear MAF describing the liquid as having a low concentration of RCD. "The sample they were testing was one made up of one rabbit to 200mls of water, we're now using one rabbit to 1 litre and they're still dying just as quickly, so I wouldn't have thought it was a low concentration." Reaction to the deliberate spreading of the virus was still all good, he said. Results of tests on rabbits collected in the Mackenzie Basin late last week confirmed RCD had been found on more properties in the area, Ms Gee said.

Surveillance on properties where RCD was confirmed would continue as MAF tried to determine whether the virus was spreading from rabbit to rabbit. "It depends who you talk to, but there seems to be minor rabbit to rabbit spread," Ms Gee said. But according to Federated Farmers Mackenzie country branch chairman Martin Murray, Ms Gee's comment was wide of the mark. The venom was working and rabbits were falling like flies, he said. "It's killing the runners (young rabbits) and we were told they would be immune to the virus." -- NZPA
Homebrews may vaccinate
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WELLINGTON -- Farmers who have been using kitchen blenders to whip up concoctions of infected organs might be creating populations of rabbits immune to rabbit calicivirus disease (RCD), a parliamentary select committee was told yesterday. "Farmers who have been making 'homebrews' run the risk of inactivating the virus," Agriculture Ministry (MAF) chief veterinary officer Barry O'Neil said. "Maybe some of the reasons some farmers haven't been able to make the virus work could be because of the way they have been handling it." Dr O'Neil told the committee on the environment yesterday MAF had so far found little evidence of RCD spreading naturally from rabbit to rabbit in the wild. "We believe it is happening, but at a very slow rate," he said. But it was working as a "biocide" or biological poison applied to baits.

Research and computer modelling had shown the virus was not going to be as effective a biological control as it had been in other countries. Climatic conditions and the potential carriers, such as insects, were different in New Zealand. In Australia, authorities in areas with more than 300mm of annual rainfall had to switch from using RCD as a biological control to using it as a biocide on baits. "They can't sustain it as a biological control in a rabbit population when the rainfall is above 300mm -- and that may be a factor in why we have not so far seen RCD in the North Island." MAF still did not know crucial facts about the virus, such as how it spread, how it over-wintered, or how effective it was. Dr O'Neil later said one of the many issues now to be resolved was whether, if RCD was to be used on baits, farmers should be given assistance to ensure it was as effective as possible. MAF believed RCD would work as a biocide, providing the user knew the target population was susceptible -- of the right age group and not immune because of previous exposure -- and that virulent bait was used in appropriate dosages. "If they don't get enough virus on that bait, they may develop immunity rather than die."

The illicit release of RCD virus and its spread by back- country farmers now meant that if MAF or regional councils later wanted to use RCD as a biocide, target populations would first have to be checked with expensive laboratory tests for their level of immunity. Such tests could cost $3 a rabbit sampled. Scientists had told MAF that one technique used by farmers -- diluting what they called "venom" with water -- before spreading it on baits was likely in some cases to have simply vaccinated the pests against the virus. Viruses needed to be handled correctly and many could not sustain heat, dryness or freezing, he said. "Water would potentially inactivate the virus, unless it is the right pH level with phosphatase solutions to stop inactivation," he said. Another worry was whether the illegally imported virus was the most virulent strain available, or whether a benign form had inadvertently also been brought in. -- NZPA

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The Dominion 6/9/97. (New Zealand newspaper)

The Cabinet was expected to decide on Monday to get rid of the legal confusion about the spreading of the rabbit-killing calicivirus, Government sources said yesterday.

The virus designation as an "unwanted organism" under the Biosecurity Act was expected to be removed and moves initiated to get rid of the prospect of prosecution. But thinking yesterday was that the Government was unlikely to make an immediate decision on importing and releasing clean stocks of the virus to maximise its impact.

The Agriculture Ministry received a Crown Law opinion yesterday saying that the farmers could be prosecuted for spreading the virus,contary to the advice of the chief veterinary officer Barry O' Neil had given farmers. The opinion said farmers could be liable under the Biosecurity Act for spreading unwanted organisms-but only if it could be proved they had spread the originally imported item and that it had been taken from a "controlled area" Cromwell, in central otago, was designated a controlled area for short time after the virus was first discovered there.

The opinion also said farmers could be prosecuted under the Animals Act for being involved in spreading the virus. However, informed sources said it was unlikely the ministry would prosecute many farmers, given Dr O' Neil's assurances and the fact that farmers had helped the ministry and the Cabinet gather information on the virus. Agriculture Ministry lawyer Geoff Daniels said yesterday that the Ministry, like all enforcement agencies, could decide whether to prosecute.