Dogs L. infantum infection from an endemic region of the north of Tunisia: a prospective study.

A follow-up study of 917 dogs was undertaken between 1994 and 1995 in the focus of visceral leishmaniasis in northern Tunisia. It permitted to assess the demography of the dog population, the importance of canine leishmaniasis (CL) and the determinants of seropositivity and mortality of dogs. Canine population was stable through time with an input of 231 dogs and an output of 218 dogs per year. The prevalence of seropositivity was 18% and 22.3% in 1994 and 1995 respectively and 90% of dogs were asymptomatic. Among 525 negative dogs in 1994 and reassessed in 1995, 78 seroconverted revealing an annual cumulative incidence of 14.74%. On the other hand, 23.47% (27/115) of seropositive dogs became negative in 1995. Age, presence of symptoms and density of dogs were independently associated with CL seropositivity. These results demonstrate the difficulty of control strategies of visceral leishmaniasis targeting the dog population.