Increase in the prevalence of canine leishmaniasis in urban Algiers (Algeria) following the 2003 earthquake

Between 2005 and 2008, a serological survey for leishmanial infection was conducted among dogs from urban and peri-urban Algiers, with the focus on the new, densely populated areas that were built after the 2003 earthquake. Serum samples were collected from 1810 animals and tested for the presence of leishmanial antibodies by IFAT, ELISA and western blotting. The overall seroprevalence recorded was 25.1%. Of the seropositive dogs, 58.8% showed no clinical signs of the disease, 25.8% had a few, minor signs and the remaining 15.4% showed more severe illness. The major clinical signs of infection were weight loss, skin lesions and lymphadenopathy. Although seropositive dogs were found in all of the boroughs (dairas) of Algiers, seroprevalences were highest in the western part of the city (i.e. in the boroughs of Bouzareah, Cheraga and Zeralda), ranging from 23.0% to 44.5%. Statistical analysis showed a relationship between seropositivity for leishmanial infection and the dog's age and lifestyle (i.e. whether the dog lived outside and/or in areas with dense vegetation). Only two zymodemes were identified amongst the 50 isolates investigated: MON-1 (88%) and MON-281 (12%). The latter zymodeme has not been previously found in Algeria, sandflies or dogs.