Development and validation of a quantitative PCR for the detection of Guinea worm (Dracunculus medinensis)

Coker, S. M., Box, E. K., Stilwell, N., Thiele, E. A., Cotton, J. A. , Haynes, E., Yabsley, M. J. and Cleveland, C. A. (2022) Development and validation of a quantitative PCR for the detection of Guinea worm (Dracunculus medinensis). PLoS Neglected Tropical Diseases, 16(10), e0010830. (doi: 10.1371/journal.pntd.0010830) (PMID:36206300) (PMCID:PMC9581357)

Abstract

Dracunculus medinensis (Guinea worm) is a parasitic nematode that can cause the debilitating disease dracunculiasis (Guinea worm disease) in humans. The global Guinea Worm Eradication Program has led intervention and eradication efforts since the 1980s, and Guinea worm infections in people have decreased >99.99%. With the final goal of eradication drawing nearer, reports of animal infections from some remaining endemic countries pose unique challenges. Currently, confirmation of suspected Guinea worm infection relies on conventional molecular techniques such as polymerase chain reaction (PCR), which is not specific to Guinea worm and, therefore, requires sequencing of the PCR products to confirm the identity of suspect samples, a process that often takes a few weeks. To decrease the time required for species confirmation, we developed a quantitative PCR assay targeting the mitochondrial cytochrome b (cytb) gene of Guinea worm. Our assay has a limit of detection of 10 copies per reaction. The mean analytical parameters (± SE) were as follows: efficiency = 93.4 ± 7.7%, y-intercept = 40.93 ± 1.11, slope = -3.4896 ± 0.12, and the R2 = 0.999 ± 0.004. The assay did not amplify other nematodes found in Guinea worm-endemic regions and demonstrated 100% diagnostic sensitivity and specificity. Implementation of this quantitative PCR assay for Guinea worm identification could eliminate the need for DNA sequencing to confirm species. Thus, this approach can be implemented to provide more rapid confirmation of Guinea worm infections, leading to faster execution of Guinea worm interventions while increasing our understanding of infection patterns.

• Item Type: Articles
• Additional Information: Funding: This work was funded (SMC, EKB, EAT, EH, MJY, CAC) in part by The Carter Center, whose work to eradicate Guinea worm disease has been made possible by financial and in-kind contributions from many donors. A full listing of supporters can be found at The Carter Center website (http://www.cartercenter.org/donate/corporate-government-foundation-partners/index.html). This work was funded in part by the Wellcome Trust [grant number 206194 to JAC].
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Cotton, Professor James
• Authors: Coker, S. M., Box, E. K., Stilwell, N., Thiele, E. A., Cotton, J. A., Haynes, E., Yabsley, M. J., and Cleveland, C. A.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: PLoS Neglected Tropical Diseases
• Publisher: Public Library of Science
• ISSN: 1935-2727
• ISSN (Online): 1935-2735
• Published Online: 07 October 2022
• Copyright Holders: Copyright © 2022 Coker et al.
• First Published: First published in PLoS Neglected Tropical Diseases 16(10):e0010830
• Publisher Policy: Reproduced under a Creative Commons license