Scientific Documents

Opinion of the Scientific Panel on Animal Health and Welfare (AHAW) regarding the assessment of the risk of Echinococcosis introduction into the UK, Ireland, Sweden, Malta and Finland as a consequence of abandoning national rules

Summary (29 KB)

Opinion (1040 KB)

Summary

Regulation (EC) No 998/2003 lays down the rules for the non-commercial movements of pet animals (dog, cat, ferrets) both within the community as well as from third countries into the EU. The United Kingdom, Ireland and Malta have maintained their national rules as regards the control of echinococcosis and ticks, while Sweden and Finland have maintained their national rules as regards the control of echinococcosis. The derogations will be reviewed at the end of a transitional period of 5 years, on the basis of a report on the need to maintain such additional requirements. This opinion addresses the risk of introduction of Echinococcus multilocularis into free MS, by pet movements, if the treatment in place is abandoned.

The principal definitive hosts for E. multilocularis are canids consuming rodents as prey, e.g. foxes (Vulpes spp., Alopex lagopus) and coyotes (Canis latrans). The metacestodes of E. multilocularis are adapted to small rodents (usually species of Arvicolidae). Human beings can become accidentally infected (dead-end host) by ingesting tapeworm eggs excreted by the final hosts. The resulting disease, alveolar echinococcosis (AE) typically presents as an infiltrative tumour-like growth in the liver, with a poor prognosis. Domestic dogs and cats can also be infected by the worms, although with a low prevalence.

The parasite is found in foxes in central Europe, from the north to Denmark, the Netherlands and Belgium, in the east to the Baltic States and Slovakia, in the south to north eastern Italy and Hungary, and in the west to central France. There is evidence of an increase in the parasite density in many areas, probably correlated to an increase in the fox population. Also, foxes have adapted to urban environments. Infection of domestic carnivores by E. multilocularis appears to be a rare event, but may, however, play a key role in transmission to humans due to close contact. Very few studies exist on prevalence of E.multilocularis in domestic carnivores. The low infection rates in domestic dogs in Europe are most likely due to low exposure to the parasite and to routine worming of domestic pets. In humans, data point to an apparent increase of AE cases.

Praziquantel and Epsiprantel may be used for effective treatment of E. multilocularis infection in definitive hosts. Both are safe and well tolerated in dogs and cats. However, none of these products is ovicidal. Parasiticidal effect is short lived (around 24 hours), allowing for re-infection after treatment. Also, due to the lack of ovicidal activity, infected pets treated with praziquantel may shed infectious tapeworm eggs for several hours after treatment.

There are very few data on the prevalence or incidence of infections with E. multilocularis in pets, in particular in pets to be moved into an area considered free of this parasite. Therefore it was considered that the risk assessment should be qualitative.

From the RA it was concluded that the risk of dogs and cats to become infected with E. multilocularis as final hosts in endemic areas is greater than negligible. The regional prevalence in wildlife and access to intermediate hosts influence the infection risk of pets and dogs. Therefore, a proportion of dogs and cats to be moved from an endemic area into a country considered free of E. multilocularis will be infected, and the abandoning of additional measures will increase the risk of introducing the parasite into an area considered free of E. multilocularis.

From the three current treatment protocols used by the UK, Republic of Ireland, Malta, Finland and Sweden it was concluded that the probability of re-infection in the country of origin, and the probability of viable egg elimination in the importing country is reduced to a negligible level when a suitable treatment with praziquantel is given between 24 and 48hours prior to departure...