Comparison between Serology and PCR Methods for the Diagnosis of Visceral Leishmaniasis

ABSTRACT: Introduction & Objective: Canine visceral leishmaniasis (CVL) caused by Leishmania Infantum is endemic in most Mediterranean basin and its seroprevalence ranges from 10 to 37%. Diagnosis of Infection is very important especially in asymptomatic dogs for control of human leishmaniasis for control of human visceral leishmaniasis. This study was aimed to compare three methods for detection of canine visceral leishmaniosis. Materials & Methods: In this research process study, 71 dogs were selected from 4 endemic villages in Meshkin-Shahr district. Peripheral blood samples were tested by serologic (DAT and Dipstick rK39) and molecular (PCR) methods. Skin samples were tested by molecular (PCR) methods. Twelve samples of PCR products were sequenced that all of them were identified as Leishmania infantum and 2 nucleotide sequence data submitted to the GenBank database. Results: From 71 dogs that were studied, 21.1% were symptomatic and others were asymptomatic(78.9%). 17 dogs (23.9%) had ≥ 1:320 titer of antibody by direct agglutination test (DAT). Twenty two dogs(31%) were positive by Dipstick rK39 test, 21 dogs (29.6%) were positive by PCR on skin samples, 31 dogs (43.7%) were positive in blood PCR and 38 dogs (53.5%) were positive by skin/blood PCR. The highest correlation was between DAT and Dipstick test (76%). Conclusion: According to the results of this study, we can diagnose infection in symptomatic and asymptomatic dogs by DAT as a suitable method and PCR is suitable to follow parasite DNA in skin and other tissues of dogs. Keywords: Direct Agglutination Test(DAT), Dipstick rK39, PCR, Visceral Leishmaniosis, Do