Asymptomatic canine leishmaniasis in Greater Athens area, Greece

Leishmania (L.) infantum is the etiological agent of human and canine visce ral leishmaniasis in the Mediterranean subregion. Domestic dogs are the mai n reservoir of the parasite in most urban areas. A survey of 1638 asymptoma tic dogs registered in Greater Athens area was carried out in the Hellenic Pasteur Institute during the period 1986-1994 to investigate the prevalence of canine visceral leishmaniasis in apparently healthy dogs. Dog sera was tested using the indirect fluorescent antibody technique (IFAT). Of the 163 8 dogs, 366 (22.4%) had anti-Leishmania infantum antibodies at titre greate r than or equal to 1/200 which were considered positive; 53 (3.2%) had anti body titres of 1/100 and were considered uncertain: and 1219 (74.4%) dogs w ere seronegative. From the 366 seropositive dogs, 212 were positive at 1/16 00 serum dilution, 57 at 1/800, 38 at 1/400 and 59 at 1/200. The results we re plotted according the site of residence, breed and age. The rate of asym ptomatic infections with L. infantum dogs in Greater Athens area appears to be significantly high. Although there is an apparent lack of clinical symp toms in these dogs, asymptomatic animals harbor a chronic L. infantum infec tion and as such consist a 'dangerous' reservoir with regard to the spread of the disease.