The Calicivirus – Part 2

How did Dr Smith get involved? He has worked for more than twenty five years with caliciviruses. One morning he read on the front page of the local paper in Corvallis, Oregon, “Rabbit calicivirus escapes Wardang Island.” The article went on to tell how happy everyone was that this virus was ripping across the mainland of Australia.

Dr Al Smith Photo source – Dr Neil Cherry

He found to his dismay that for five or six years researchers had been examining this calicivirus as a means of controlling rabbits without his knowing about it. As he runs the only calicivirus laboratory in the world it was clear that they had not talked to people who have studied caliciviruses apart from some who had studied the rabbit calicivirus. The problem with this particular virus is that it cannot be grown in the laboratory.

Dr Smith’s press release opens up communication with Australia and New Zealand. He called up the media department at the University and told them that the Australians needed to be told that this was not news for rejoicing and that there was a great need for caution in this matter. His press release described the use of the virus to control rabbits as ‘playing with fire’. The university cleared it and the next morning his telephone went crazy because his press release had been picked up in Australia and New Zealand.

He was told that experiments done in Geelong, Australia, proved that the virus does not infect other animals. He asked if tests had been done comprehensively – for instance on the very young and the very old, those that are nutritionally compromised.

Australian television programme In February 1997 Dr Smith was brought to Australia by Sixty Minutes and a segment was done on this topic – a piece which he described as a very balanced piece which pleased him. The virus had begun spreading across the country in October 1996.

Purchase of the rabbit haemorrhagic disease virus for host specificity tests The Australian New Zealand Rabbit Calicivirus Project had funding from both countries. The virus was purchased from Czechoslovakia and brought into the containment laboratories in Australia. They had tried other places to get the virus, but Spanish and German researchers refused to give anyone the virus for the purpose of the intended experiments.

The tests conducted at Geelong, provide a considerable amount of evidence that this is not a species specific virus, since eleven of the thirty four species showed increases in antibodies on exposure to the virus.

Spread of rabbit haemorrhagic disease The rabbit haemorrhagic disease has spread from China across to Western Europe in less than ten years and has now been found in forty countries on four continents. Only North and South America and the Antarctic are now free of this form of the calicivirus.

Shifts in ecologic relationships a major factor in world plagues Australia has introduced deliberately a species deadly to at least one mammalian species into a completely naive ecologic system. It isn’t just that there is a spot somewhere infected. It is a continent put at risk.

That is the very basis from which people who deal in world plagues expect change – this movement to unusual settings, the destruction of the rainforest and the movements of the animals out of it, the creating of new ecologic relationships. That is where deadly viruses emerge. It is almost always because there has been a shift in the ecologic relationships. Australia is a continent-wide open-air experiment.

Introduction into New Zealand The introduction and spread of calicivirus took place illegally while the Government was examining the information that was becoming available through contact with international researchers. The Government had not approved it though the decision was unpopular.

Who else is involved in the research? David Matson is an M. D. in paediatrics and virology and a PhD in epidemiological virology. He is working as an epidemiologist, paediatrician, and virologist in the United States. He is currently engaged in a huge project looking at the effects on children of vaccines for a diarrhoea disease. He is based in Norfolk, Virginia, and is Associate Director of the Centre for Paediatric Research there.

Yvonne van Roy is a professor in commercial law at Victoria University in Wellington. She called scientists around the world to get their views. Those with no vested interest were 100% of the view that releasing the virus was a foolish action which they would not support in their own countries.

Dr Neil Cherry visited the laboratory in the United States so that he could be shown the type of information and data that should be put together. He spoke out strongly against the introduction of the virus.

Impact of the virus in New Zealand The impact of the virus in New Zealand has so far been regarded by many as ‘disappointing’. Dr Smith, however, says that it has behaved as should have been expected. Most caliciviruses cause illnesses but not death. This virus causes death. Its unpredictable response in the host should have been fully predictable because that is the way caliciviruses generally work.

Spread of infection in the Australian tests On Wardang Island off the south Australian coast where the outdoor experiments were done they had seven pens with ten rabbits in each pen. They would infect two rabbits with the virus and watch the spread through the remaining eight. In the first pen it did not spread. They did two more pens and in one it did not spread. In the other it made one or two rabbits sick. They tried two more pens and in one pen one rabbit died while in the other seven out of eight died. At that point there was an escape outside the pens. The experiment was shut down and the researchers never determined how it had escaped.

Ten weeks later they infected the last two pens. In one of those pens two rabbits died and in the other none died, but the virus escaped again, not only outside the pen, but it jumped across five kilometres of water on to Point Pierce opposite Wardang Island and at the same time two hundred kilometres inland to a very dense rabbit population in a national park.

Did it jump or was it spread? We know that it was introduced into New Zealand; we do not know what happened in Australia.

Read Part 3 of the calicivirus interview… the final article in the series.