Canine visceral leishmaniasis: seroprevalence survey of asymptomatic dogs in an endemic area of northwestern Iran.

Canine visceral leishmaniasis is a major public health problem that is endemic in tropical and sub tropical countries and is fatal in humans and dogs. In addition to symptomatic dogs, asymptomatic ones seem as source of Leishmania infantum infection. Thus surveillance and control programs of reservoir hosts are essential. This study aimed to evaluate the sero-prevalence of visceral leishmaniasis in asymptomatic domestic dogs from in an endemic area of north west, Iran. A cross sectional study was carried out in Meshkin-Shahr district during 2011-2012. Blood samples collected from 508 asymptomatic domestic dogs were tested by direct agglutination test. In this study 508 dogs (397 males and 111 females, mean age, 3.24 years) from western and eastern parts of the Meshkin-Shahr were examined. A total of 508 dogs examined 119 dogs (23.4 %) had antibodies (titers of ≥1:320) against L. infantum. Statistically significance was occurred between male (25.4 %) and female (16.2) sero-prevalence (P = 0.042). No statistically significance was observed between age groups (P = 0.22). Compared with previous studies it seems to increase sero-prevalence of visceral leishmaniasis in dogs in the studied areas caused by ecological changes. High proportion of asymptomatic but seropositive dogs emphasizes the importance of dogs without clinical signs in the epidemiology of zoonotic leishmaniasis. Thus, the necessity of using serological tests in asymptomatic dogs is recommended for disease control strategy.