Evaluation of a novel diagnostic screening tool for detection of Onchocerca in blackfly populations
The aim of this project is to evaluate loop-mediated isothermal amplification (LAMP) assays as a detection method for Onchocerca in blackfly populations under field conditions in Cameroon.
For the first part of the investigation, we will employ the commonly used O-150 primer set (Meredith and others 1991) to detect Onchocerca infection in Simulium specimens collected from the Vina du Sud site near Ngaoundere, Adamaoua. The focus of this investigation will be to evaluate the robustness of the assay when used in a low-tech field setting, specifically aspects which make it a simple and cost-effective alternative to PCR. This will include trialling of different DNA extraction methods and determining assay specificity.
For the second part of the investigation, we will evaluate the sensitivity and specificity of the O. volvulus-specific GST-1α primer set (Alhassan and others 2014) in in detecting O. volvulus DNA. This will be achieved through sampling at a site in northern Cameroon near Touboro. Esperanza window traps will be used to collect anthropophilic Simulium cytospecies and pooled DNA samples will be tested by LAMP, with results compared to conventional PCRs for O. volvulus, O. ochengi and O. ramachandrini.
Dr John Graham-Brown presented the outputs of the project to date at the Gnatwork 2021 conference on the 24th May.