Leishmaniasis in the province of Salamanca, Spain. Prevalence in dogs and seasonal dynamics of vectors.

Of 433 dogs examined in 4 natural zones of Salamanca Province, Spain, the prevalence of canine leishmaniasis (IFAT titres greater than or equal to 1/80) was 0-3% in most mountain villages and from the Castillian plateau (greater than 600 m.a.s.l.) and 10-15% in villages situated on hillsides ("flanc du coteau") with elevations less than 600 m.a.s.l. An exception was the high prevalence found in the area around the city of Salamanca owing to its height (800 m.a.s.l.) and flood-plain situation. Of 5,105 sandflies captured with sticky traps, P. perniciosus and P. ariasi were well represented at the sites with high prevalences of canine leishmaniasis but not elsewhere. Their abundance in the periurban area of the city of Salamanca is attributed mainly to human transformation of the environment. Of the two species, only with P. ariasi can a linear relationship be observed between density and the prevalence of canine leishmaniasis, which seems to show that in Salamanca P. ariasi is its main vector. The probable lower observed vectorial capacity of P. perniciosus could be due to the fact that no progressive physiological ageing towards the end of the summer was observed. Patients with leishmaniasis in the Province come from sites with the highest prevalence of canine leishmaniasis.