Molecular and Seroepidemiological Survey of Visceral Leishmaniasis in Owned Dogs (Canis familiaris) in New Foci of Rural Areas of Alborz Province, Central Part of Iran: A Cross-Sectional Study in 2017

Background Mediterranean form of visceral leishmaniasis (VL) is endemic among some provinces of Iran. The present study was designed to determine the prevalence of canine visceral leishmaniasis (CVL) in the owned dogs of the rural areas of Alborz Province near Tehran as the capital of Iran. Methods This study conducted on 303 owned dogs that selected using a stratified random sampling method. The direct agglutination test (DAT) was used to determine the frequency of Vl. The spleen biopsy was taken from the serology-positive dogs for the confirmation of CVL in the suspected dogs. Nested PCR and sequencing methods were used to determine the type of Leishmania species in the dogs which were parasitological positive. Results Overall, the DAT results of 9 dogs (2.97%, CI: 1.57-5.55) showed anti Leishmania antibodies at titers ≥ 1:320 indicating VL infection. One dog (0.33%, CI 95%: 0.06-1.85) showed clinical signs and symptoms of VL. There was a significant correlation between the positive cases of CVL and rural area (p< 0.001). The Leishmania was observed in the impression smears that were prepared from spleen biopsy of five the studied dogs. Leishmania infantum were confirmed in all them using nested-PCR assay. The sequence analysis of all five isolates was 95% similar to L. infantum. Conclusion This study shows that domestic cycle of L. infantum has been established in rural areas of Alborz province where located near Tehran as capital city of Iran. It is necessary to increase the awareness and monitoring of the disease periodically.