Strongyloides is a genus of soil-transmitted nematodes that infects a wide range of hosts. Among these, Strongyloides stercoralis is the most prominent, infecting an estimated 600 million people worldwide. Other hosts include non-human primates (NHPs) and dogs, with zoonotic transmission potential, especially in populations sharing close habitats. Despite its significant public health impact, effective diagnostic and treatment methods are still lacking. Even with advancements in diagnostics and treatments, identifying all potential reservoir hosts remains crucial to controlling these infections in humans. This master’s thesis aims to implement a novel diagnostic approach using high-throughput sequencing (HTS) to identify individual Strongyloides haplotypes and evaluate cross-species transmission. Samples from humans (n=17) and non-human primates [Western chimpanzee (Pan troglodytes verus), n=77; Green monkey (Chlorocebus sabaeus), n=16; Guinea baboon (Papio papio), n=19; King colobus (Colobus polykomos), n=6; Western red colobus (Piliocolobus badius), n=7; Lesser spot-nosed monkey (Cercopithecus petaurista), n=13)] sharing habitats in Cantanhez National Park, Guinea-Bissau, which were previously identified as Strongyloides-positive using qPCR in a bachelor’s thesis, will be analysed using HTS. This thesis has the potential to inform public health policy by advancing our understanding of Strongyloides transmission pathways, thereby contributing to the development of more targeted and effective infection control strategies.
Aims: 1. Master high-throughput sequencing methodologies, including Illumina library preparation. 2. Develop skills in high-throughput data processing and statistical evaluation. 3. Identify the species diversity within Strongyloides, including distinct lineages and haplotypes. 4. Investigate lineage/haplotype sharing across host species, particularly among humans and NHPs.
Hypotheses: 1. Lineages/haplotypes of Strongyloides stercoralis will be shared among NHPs and humans, while Strongyloides fuelleborni fuelleborni will only be detected in NHPs. 2. Strongyloides f. fuelleborni infections will be more prevalent in NHPs than humans. 3. Strongyloides stercoralis infections will be more common in humans than in NHPs.