Performance of five serological tests in the diagnosis of visceral and cryptic leishmaniasis: a comparative study

Introduction: Leishmaniasis is a major health problem and its diagnosis still represents a challenge. Since consistent evidence on the comparison of serological methods is lacking, our work aims to compare five serological tests for the diagnosis of visceral and asymptomatic leishmaniasis in southern France, a region where leishmaniasis is endemic.Methodology: Serum samples from 75 patients living in Nice, France were retrospectively analyzed. They included patients affected by visceral leishmaniasis (VL; n = 25), asymptomatic carriers (AC; n = 25) and negative controls (n = 25). Each sample was tested using two immunochromatographic tests (ICT; IT LEISH (R) and TruQuick IgG/IgM (R)), an indirect fluorescent antibody test (IFAT) and two Western Blotting (WB; LDBio BIORAD (R) and an in-house method). Results: Diagnosis of VL with IFAT and TruQuick (R) showed the highest diagnostic performance parameters. IFAT had 100% sensitivity and specificity, while TruQuick had 96% sensitivity and 100% specificity. Finally, the two tests showed high accuracy (100% for IFAT and 98% for TruQuick) for the AC group. WB LDBio (R) was the only method able to detect Leishmania latent infection, with a sensitivity of 92%, and a specificity of 100%, with a Negative Predictive Value (NPV) of 93%. This performance is reflected in the high accuracy of the test. Conclusions: The data obtained with TruQuick (R) supports its application in the rapid diagnosis of leishmaniasis in endemic areas, a feature not shown by IFAT despite its high diagnostic performance. Regarding the diagnosis of asymptomatic leishmaniasis, the best results were obtained with WB LDBio (R), confirming previous studies.

Automated summary

This study aimed to compare five serological tests for the diagnosis of visceral and asymptomatic leishmaniasis in southern France. The results showed that IFAT and TruQuick had the highest diagnostic performance for visceral leishmaniasis, while WB LDBio had the best diagnostic performance for asymptomatic carriers.