Potential impact of the PARASOL Project

If the PARASOL Project progresses as planed, the results will have a wide and important strategic impact on livestock management in Europe and selected INCO countries. The PARASOL programme will in particular:

1) Forward the development of laboratory standards
If anthelmintic resistance (AR) is to be controlled and management systems such as Targeted Selective Treatments (TST) are to be adequately validated it is essential that standardised methods are available that give similar results in laboratories worldwide. Currently, the reproducibility of the available methods is poor. This has created major problems for those attempting to provide advice to individual producers on best practice. One of the major goals of PARASOL is to provide the scientific basis on which such standards could be promulgated at national and international levels.

2) Improve knowledge on anthelmintic resistance in livestock
Although anthelmintics are extensively used, we still lack much basic knowledge concerning the mechanisms of anthelmintic resistance. If we want to be able to use efficacious anthelmintics in future, we must further identify specific processes enabling the parasites to develop resistance to anthelmintics. If we do not succeed and current farming practices are unchanged, there is a very real danger that AR may make the current anthelmintic drugs useless for worm control and that parasite infections will thus re-emerge to dramatically reduce the productivity and competitiveness of European agriculture.

3) Further helminths in refugia
By minimizing the use of anthelmintics, TST creates opportunities for keeping a proportion of the parasite population in refugia (i.e., not exposed to the chemicals), thus reducing the selection pressure for the development of anthelmintic resistance.

4) Support the economy
According to FAOSTAT in 2004 the total cattle, sheep and goat milk production in the EU accumulated to approx. 150, 2.3 and 1.7 million tons, respectively. Based on average (EUR /100 kg) market prices in the EU in 2002 this was equivalent to sales of more than 36 billion EUR (Eurostat 2002). At the same time the EU cattle and small ruminant meat production was approx. 8, 1 and 0.1 million tons, respectively. In 2002 the corresponding ruminant meat sales exceeded 21 billion EUR (Eurostat 2002). Economically this sector therefore has to be considered as the most important in animal farming in the EU. Due to lower productivity helminth infections cause the highest economical losses in livestock. Yearly more than 1 billion EUR are spent for chemical helminth control alone, a reduction of these costs of would already significantly increase the profit margin of the livestock farmers. The PARASOL project will develop innovative helminth control strategies that will allow a significant reduction of anthelmintic use while still maintaining productivity, even improving competitiveness.

5) Improve food safety and minimize residues in the environment
The suggested TST programmes will reduce or at times even eliminate the need for prophylactic and therapeutic use of chemicals. This will have a major impact on food and environmental contamination by diminishing the levels of anthelmintic residues. Reducing the number of anthelmintic treatments will also reduce the exposure of the people administering those treatments.

6) Reduce the threat of drug resistance in humans
While cases have previously been recorded, there is as yet no unequivocal evidence that resistance of worms to anthelmintics commonly used in humans is an emerging problem. However, the use of anthelmintics in humans has increased dramatically as a result of global and community-based control programmes. Thus it is important to guard against complacency. Experience with the quick and dramatic spread of AR in livestock should warn the medical world against the use of anthelmintics for attempts at global and/or regional eradication of helminths, or even general reduction in morbidity levels of helminth infection, especially since helminths in humans have biological and epidemiological similarities to those in livestock and the anthelmintics used are the same. An important scientific challenge is to develop the appropriate tools, methods and protocols to reliably detect the appearance of AR in human helminths at an early stage. The PARASOL project will contribute towards this aim.

7) Improve knowledge on host genetic resistance
The underlying idea behind TST is to develop diagnostic systems that can rapidly and simply (without the necessity of laboratory testing) identify those animals that can cope with parasite infections without anthelmintic intervention and to point out individuals that require treatment. It is expected that these diagnostic systems could equally be used within selective breeding programmes for parasite resistant animals. However, it needs to be emphasized that breeding for resistant hosts is long-term idea and that it would be naïve to expect any immediate progress in this area during the course of the present project. On the other hand, it is clear that the PARASOL project will develop diagnostic tools and will therefore have an indirect impact on successful programmes for breeding parasite resistant animals.