The public health goal of onchocerciasis in Africa has shifted from control to elimination. Hence, accurate diagnosis is necessary to determine when to stop treatment and confirm elimination, as well as to conduct surveillance for the identification of any possible recrudescence of the disease. Currently, the Ov16 test is the only antibody-detection system used in onchocerciasis field diagnosis and for assessment of the interruption of transmission of O. volvulus. However, the Ov16 test has a moderate sensitivity (80%) and is unable to differentiate between passive and active infections. Furthermore, about 15–25% of those infected are reported to be negative due partly to genetic restrictions, suggesting that the test systemically produces a significant number of false-negative individuals who might continue to serve as reservoirs for infections, ensuring the continuous transmission of the disease following certification of elimination. Thus, without a more sensitive tool, the goal of elimination may be far-fetched. While suitable antigen capture tests will be able to distinguish between past and current infections, the challenge of genetic restriction encountered using single antigens can be overcome by using chimeric antigens. Hence, to circumvent the shortcomings mentioned above, OvMANE1 chimeric antigen was validated as a potential biomarker for the development of a diagnostic tool for human onchocerciasis. In this study, OvMANE1 chimeric antigen will be further characterized via ELISA and paper fluidic systems (Ampli blocks) in the development of a diagnostic tool not only for determining active onchocerciasis infection, assessing treatment program successes, determining treatment endpoints but also for post-elimination surveillance.
20 May 2021 → 19 May 2022
African Research Network for Neglected Tropical Diseases, Ghana