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Intro: Elimination of visceral leishmaniasis (VL) as a public health problem on the Indian subcontinent is within reach. With VL cases coming to an all-time low, monitoring of infection rather than disease might provide a sensitive method to pick-up resurgence of transmission. We therefore evaluated to what extent serological surveys allow to distinguish between presence and absence of Leishmania donovani transmission. Methods: Seven villages were selected within Bihar and Uttar Pradesh state, based on their reported VL case load in last 20 years, and categorized as either currently endemic (VL cases reported in each of the last three years), previously endemic (VL cases reported until four years ago), or non-endemic (no VL cases in last 15 years). All inhabitants aged ≥2 years were requested to provide blood sample for rK39 Rapid Diagnostic Test, Direct Agglutination Test (DAT;cut-off ≥1:3,200), and rK39 ELISA (cut-off pp=18). Findings: A total of 3,959 households (population: 20,325) were visited in seven clusters, of whom 15,468 (76%) provided a blood sample. Seroprevalence with rK39 RDT was 0.42% (95%CI 0.26 – 0.62%), 0.26% (95%CI 0.15– 0.43%) and 0.00% (95%CI 0.00 – 0.10%) in currently endemic (CE), previously endemic (PE) and non-endemic (NE) clusters respectively. DAT seroprevalence was 0.51% (95%CI 0.34– 0.75%), 1.62% (95%CI 0.32 – 1.98%) and 0.05% (95%CI 0.01– 0.19%) in CE, PE and NE clusters respectively. ELISA results provided a significant difference between all three settings, with 5.21% (95%CI 4.62 – 5.84%) seroprevalence in CE clusters, 1.55% (95%CI 1.25 – 1.89%) in PE clusters, and 0.13% (95%CI 0.04 – 0.30%) in NE clusters. Among children aged |
