Diagnostic performance of a novel point-of-care test for the diagnosis of visceral leishmaniasis in Sudan: A Comparative Accuracy Study.

Abstract

Methods: This study enrolled 107 VL suspects who attended a health centre in Gedaref between October 2022 and June 2023. Diagnostic accuracy was assessed by comparing the performance of the new index test (INgezimLeishma-CROM) with the comparator test (IT-LEISH) and parasitological examination as reference standard.

Results: Of 107 VL suspects screened by parasitological examination, 77 VL patients were smear positive and 30 were smear negative. Independent serological testing of these patients using INgezim Leishma-CROM showed a sensitivity of 98.7% [95% CI 92.23-99.97] and specificity of 92.5% [95% CI 75.71-99.09]. For IT-LEISH, both sensitivity [95% CI 84.39-97.20] and specificity [95% CI 75.71-99.09] were 92.5%. INgezim Leishma-CROM demonstrated increased diagnostic accuracy (97.2%) compared to IT-LEISH RDT (92.5%). Both RDTs gave positive results in 2 cases from the smear negative group that were previously treated for VL. All other non-VL cases (malaria, typhoid, brucellosis) were negative in both RDTs, showing 100% specificity, while VL patients co-infected with malaria were positive in both tests. Within the smear-negative group, 3 VL symptomatic cases that had been previously treated but still show clinical signs were all positive with INgezim Leishma-CROM but only 2 cases were positive with IT-LEISH.