Onchocerca Volvulus-specific Biomarkers for Bacrofilaricidal Activity (Ov Biomarkers)

Developing a rapid diagnostic for Onchocerca volvulus

 

 

The Problem
Transmission of onchocerciases is maintained by production of larvae by adult female Ov worms; these larvae are picked up by black fly vectors during blood feeding, which then transmit infective larvae larvae to the next person they bite.
The Solution
The development of a POC test to detect viable adult Ov worms and whether chemotherapy is successful to enable targeted intervention in support of onchocerciases elimination and certification of areas free of onchocerciasis.

Overview

There is wide consensus that better tools are needed to support global efforts on elimination of onchocerciasis, an important neglected tropical disease. This project aims to make an affordable point-of-care diagnostic test available to the onchocerciasis community. The project will further develop detection systems based on previously identified parasite-specific biomarker(s) present in human subjects infected with viable adult females of Onchocerca volvulus (Ov) and validate their utility for detecting active infection by demonstrating disappearance/diminution of these biomarkers after drug administration targeted against these adult parasites. This would be a final and necessary tool in the progress towards elimination of onchocerciasis.

Goals

  • Validate immunoassays and testing for the appearance of onchocerciasis biomarkers following infection and their disappearance following drug therapy (or following cure).
  • Optimize antigen detection immunoassays for two promising biomarkers identified in previous OvAF project.
  • Prioritize the development of immunoassays for the detection of at least 2 additional Ov-specific antigens to further strengthen detection or elimination of active infection.
  • Research additional antigens that are supported by empirical proteomic data to expand options for different settings.

Partners

Public-Sector Partners

  • National Institute of Allergy and Infectious Diseases (NIAID)

Private-Sector Partners

  • Bill & Melinda Gates Foundation*
  • New York Blood Center

 *Provided financial or in-kind support for this program.

FNIH Contact

Susan Wiener, Senior Project Manager; swiener@fnih.org

Results & Accomplishments

  • Validated two biomarkers in studies of samples from Ov-infected patients followed longitudinally after drug treatment and resampled at least 10 years after initial evaluation and deemed cured, by showing that both diminished significantly after cure and in some cases could not be detected.
  • Developed antibody-based assays for both Ov biomarkers