Multi-centric evaluation of a stage-specific reverse transcriptase-polymerase chain reaction assay as a xenomonitoring tool for the detection of infective (L) stage in vectors.

Background & Objectives: An infective stage specific reverse transcriptase-polymerase chain reaction (RT-PCR) assay utilizing the abundant larval transcript-3 (Alt-3) gene of Wuchereria bancrofti was developed at ICMR-VCRC, Puducherry and found to be stage specific, and sensitive upon validation in the laboratory. This study was aimed at independently evaluating this assay for its utility as a monitoring/surveillance tool in the operational programme for elimination of lymphatic filariasis (LF) by four national research laboratories.

Methods: Evaluation of the assay was carried out in a multi-centric mode in three phases.