Ultra-sensitive Rapid Diagnostic Test to Support the End-Game of the Global Program to Eliminate Lymphatic Filariasis

Project SummaryAbstract Lymphatic filariasisLFcaused by the parasitic filarial worm Wuchereria bancroftiis a disfiguring and debilitating neglected tropical disease that affectsmillion people incountriesThrough the World Health Organization sWHOGlobal Program for the Elimination of Lymphatic FilariasisGPELFbillion drug regimens have been distributed via mass drug administrationMDAtomillion people to treat the disease and prevent its spreadMany countries are now approaching the elimination pointwhere transmission is permanently interruptedat least in theoryAs per WHO guidelinesthese countries will require ayear surveillance plan to demonstrate that transmission is no longer occurringand to allow for rapid intervention in case of reemergence of the diseaseEffective surveillance strategies will need to be supported by sensitive and specific diagnostic toolsThe only field deployable test recommended by WHO for transmission assessment surveysTASof lymphatic filariasis is the immunochromatography testcardICTAlereAlthough this test has been used fordecades to detect active infectionsit remains suboptimal for surveillance activitiesas it detects an antigen measurable in circulation onlymonths post infection and lacks sensitivity in post MDA settingsdue to low parasite burdenExperts agree that what is required for surveillance is a rapid diagnostic testRDTindicative of early exposure to Wbancrofti infective larvaeLdevelopment stagefor which the best biomarker are IgGantibodies specific to the Wbantigen expressed by LlarvaeHereinwe propose an ultrasensitive RDT for the detection of Wbspecific IgGantibodiesWe have introduced a novel class of plasmonic gold nanoshells to increase the sensitivity of lateral flow immunoassaysand in preliminary experiments have demonstrated their superior performance for detecting a Wbspecific IgGserological responseWe now aim at deliveringadvanced prototypes as sensitive and specific as the reference WbELISAInBiostest used at the CDCBy the end of this Phase I STTR grant these prototypes will be available for field evaluation studiesThis new RDT will ultimately support the end game of the GPELFProject Narrative There is an urgent need for new and sensitive field deployable diagnostics to assist countries in surveilling possible recrudescence of the filarial worm Wuchereria bancroftithe main causative pathogen of lymphatic filariasisLFand the focus of the most ambitious mass drug administrationMDAprograms ever implemented by WHOWe propose an ultrasensitive lateral flow assay to detect early infection through the diagnosis of IgGantibodies generated against the Wbantigenexpressed by the infectiveLstage of WbancroftiThis diagnostic device will be used after MDA campaigns to certify that countries have eliminated LF without the threat of reemergenceas mandated by WHO