The efficacy of PCR for early diagnosis and detection of asymptomatic cases of visceral leishmaniasis in human and dog

This study was conducted to detect asymptomatic cases of visceral leishmaniasis in human and dog, using PCR and serology methods in Darab, Fars province. In this descriptive cross-sectional survey, blood samples were randomly collected from all children aged 10 years old; 10% of the adults and 20% of the dog owners were investigated. To determine the prevalence of infection rate of VL, direct agglutination tests (DAT) and PCR-based assays were applied. In addition, to identify the species of the parasite, the species-specific PCR on blood samples was used. Of the 376 subjects investigated, 355 were children 10 years old and 21 subjects were adults. Overall, 5 (1.33%) subjects (2 males and 3 females) were found seropositive; they were aged 2-5 years. Of 23 dog samples, one case (4.3%) showed specific Leishmania antibodies equal to 1: 320 titer. Also, overall, 32 (8.5%) subjects and five dogs (21.7%) were found PCR-positive in the Leishmania KDNA- specific PCR and L.infantum was detected in all the samples. The results showed that PCR on blood with RV1 and RV2 primers is a valuable method for early diagnosis of VL in human and detection of asymptomatic cases especially in endemic regions.