Development and application of genomic tools for characterising genetic variation in soil-transmitted helminths
type: CreativeWork
description: Soil-transmitted helminths (STHs) are intestinal parasitic worms that represent a significant global health challenge, perpetuating poverty and disease. For decades, the diagnosis of STHs has depended on the microscopic detection and identification of eggs or larvae in faecal samples. However, these techniques can be labour-intensive, and their diagnostic performance and sensitivity rely heavily on sample preparation and the prevalence of infections. Molecular tests, such as quantitative polymerase chain reactions (qPCRs), are increasingly being used due to their sensitivity, especially in low-prevalence settings. These tests target species-specific ribosomal RNA genes or tandem repetitive regions found throughout the helminth genome. Currently employed qPCR assays were primarily developed and validated using a limited number of geographically restricted parasite isolates. However, it is increasingly recognised that parasitic worms in humans and animals are genetically diverse and distributed within structured populations both locally and globally. This genetic variation can occur in the sequences targeted by molecular methods. Therefore, differences within a single species that characterise STH populations may also affect the sensitivity and specificity of diagnostic tests in various settings. To date, there have been only a few studies on the population genetics of STHs, which limits our understanding of the extent of genetic variation that could interfere with molecular diagnostic methods. Additionally, such studies assessing variation in helminths have mainly relied on the availability of adult worm material. This reliance depends on the organisation of worm expulsion studies following anthelmintic treatment of the affected individuals, which can be logistically and ethically challenging. Meanwhile, faecal samples iv from infected individuals offer an untapped source of helminth egg material for genetic analysis. The aims of the thesis were to: (i) evaluate the …
abstract: Soil-transmitted helminths (STHs) are intestinal parasitic worms that represent a significant global health challenge, perpetuating poverty and disease. For decades, the diagnosis of STHs has depended on the microscopic detection and identification of eggs or larvae in faecal samples. However, these techniques can be labour-intensive, and their diagnostic performance and sensitivity rely heavily on sample preparation and the prevalence of infections. Molecular tests, such as quantitative polymerase chain reactions (qPCRs), are increasingly being used due to their sensitivity, especially in low-prevalence settings. These tests target species-specific ribosomal RNA genes or tandem repetitive regions found throughout the helminth genome. Currently employed qPCR assays were primarily developed and validated using a limited number of geographically restricted parasite isolates. However, it is increasingly recognised that parasitic worms in humans and animals are genetically diverse and distributed within structured populations both locally and globally. This genetic variation can occur in the sequences targeted by molecular methods. Therefore, differences within a single species that characterise STH populations may also affect the sensitivity and specificity of diagnostic tests in various settings. To date, there have been only a few studies on the population genetics of STHs, which limits our understanding of the extent of genetic variation that could interfere with molecular diagnostic methods. Additionally, such studies assessing variation in helminths have mainly relied on the availability of adult worm material. This reliance depends on the organisation of worm expulsion studies following anthelmintic treatment of the affected individuals, which can be logistically and ethically challenging. Meanwhile, faecal samples iv from infected individuals offer an untapped source of helminth egg material for genetic analysis. The aims of the thesis were to: (i) evaluate the …
author: Papaiakovou, Marina
language: eng
keywords: bioinformatics, faecal metagenomics, helminths, hybridisation capture, population genomics, qPCR diagnostics, shotgun metagenomics, soil-transmitted helminths
license: https://www.repository.cam.ac.uk/bitstreams/b33f7a6a-b4a8-45c9-932b-86e39eaa646c/download
license: http://purl.org/NET/rdflicense/allrightsreserved
date published: 2025-09-25
date modified: 2026-07-22T22:24:16Z
provider: Cambridge University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Cambridge

PropertyValue
property ID: DOI
value: 10.17863/CAM.123541