Scientific Opinion on canine leishmaniosis

Abstract

This Scientific Opinion presents a characterisation of canine leishmaniosis (CanL) in Europe and its potential for spreading. The efficacy of available preventative measures to protect dogs against CanL was assessed, with the objective of mitigating the probability of introduction of CanL into free areas in the European Union through movement of infected dogs. Several systematic reviews (SRs) of literature were carried out to evaluate the efficacy of vaccines, topically applied insecticides and prophylactic medication. Additionally, SRs on the sensitivity of diagnostic tests and treatment efficacy were carried out to evaluate the possibility of testing and excluding or treating infected dogs to mitigate the risk of introduction into free areas. The probability of introduction and establishment of CanL in a non-endemic region with competent sandflies was estimated, using a stochastic simulation model. The probability of establishment defined as the local transmission of L. infantum from vector to host and vice versa, was very high. The most effective mitigation measure to reduce the probability of introduction and establishment of CanL was topically applied insecticide. Vaccination had only limited effect on the probability of establishment in a non-endemic region. Testing dogs before their introduction into a non-endemic area is of limited value if applied too soon after exposure to infected sandflies, because it takes several months to obtain a positive result after exposure. Test and treatment in the endemic area, prior to movement into a non-endemic area, does not appear to be an efficient and realistic option to mitigate the probability of introduction of CanL, as no treatment against CanL can guarantee to prevent future transmission. It was concluded that the main limitation to CanL spread is represented by the vectors. This reinforces the need for knowledge on the vectorial competence, distribution and abundance of potential vectors of CanL in the EU.