It may seem like a drop in the ocean, but we don’t see it that way – reducing the use of mice and rats as test animals by 300,000 per year. The case in question is the routine investigation of shellfish for the presence of toxins that can cause diarrhoea. In the Netherlands, such tests are still being performed on rats until May 2011, after which the use of rats for this purpose will be a thing of the past and a chemical test will be used instead. The new test will not only spare Dutch rats but, across the whole of the EU, also approximately 300,000 mice per year. It has taken years to develop and validate the chemical method and convince policymakers that the legislation needed to be modified.
The toxins which can end up in the shellfish are produced by algae. This is a completely natural process that occurs worldwide. Shellfish such as mussels and oysters feed themselves by filtering seawater containing algae and other foods. Certain algae can sometimes produce nasty toxins. These toxins accumulate in the shellfish and when we consume shellfish containing the toxins, it can have all kinds of detrimental consequences.
Within Europe, 3 kinds of poisoning occur and, depending on which one you contract, you can suffer from diarrhoea, memory loss or paralysis symptoms. In the Netherlands, outbreaks of these types of poisoning are fairly rare, but elsewhere in Europe they are more common.
Alternative
In the shellfish production areas in the Wadden Sea and Zeeland (Oosterschelde and environs), checks are regularly carried out for the presence of the various toxic algae in the seawater. The shellfish themselves are also tested for the presence of toxins. RIKILT, part of Wageningen UR, has already operationalised permitted chemical tests for determining a number of toxins.
The test that is currently the only official method in Europe for testing shellfish for toxins which cause diarrhoea makes use of rats or mice. The rats are fed shellfish flesh and the mice are injected with a shellfish extract. Both methods score poorly on animal welfare and reliability. These have been important reasons for investing in an alternative chemical method. In this method, both the substances and the quantities in which they occur are measured with a high degree of accuracy. The detectability using the chemical method compared to using a rat or mouse can be as much as 10-100 times higher for the different toxins.
Comparable results
But having a new method and a nice scientific publication do not in themselves offer any guarantees. Not even if you can replace a test that scores poorly on animal welfare and reliability. Before a method can be used as an officially recognised test, it must first be tested by various laboratories. Rightly so, because the method must also be usable in other laboratories and produce comparable results everywhere. The method developed at RIKILT was tested by 13 laboratories in 2010 in an international study. The results of this study demonstrated that the method really is a useful one, but even that was not enough.
July 2011
Research into food safety is strictly regulated in various spheres in Europe. Where serious dangers can be present, European legislation prescribes which method must be used to demonstrate that our food is safe. The process of changing this type of regulation often takes years, but fortunately it was quickly sorted out for this new method.
EU legislation has recently been modified and it prescribes the use of the chemical method as the only official method from 1 July 2011 (the Netherlands are thus actually starting a month early, but we are assuming no one will mind).
Countries which do not yet have any experience of chemical testing are permitted to continue using rats or mice until 31 December 2014, but after that the use of test animals for the routine testing of shellfish for the presence of toxins that cause diarrhoea will truly be a thing of the past.
Replacing animal testing by alternative methods has become an important field of research for us in recent years. We believe this result should act as a stimulus for replacing more animal testing with chemical tests.
Arjen Gerssen
researcher RIKILT - Instituut voor Voedselveiligheid