New insights into infant strongyloidiasis in Papua New Guinea

Abstract The island of New Guinea is known to harbour a unique human infecting species of Strongyloides: Strongyloides fuelleborni subsp. kellyi. Stool DNA extracts (n=164) from 19 PNG infants, collected over 13 months, were analysed using Strongyloides real-time PCRs and underwent metabarcoding of cox1, 18S rRNA HVR-I and HVR-IV loci. Eight infants were infected with Strongyloides; seven identified as Strongyloides fuelleborni fuelleborni and one as S. f. kellyi. Phylogenetic and haplotyping analyses indicated that S. f. fuelleborni in PNG belongs to the Indochina sub-clade of S. f. fuelleborni, and S. f. kellyi does not represent a subspecies of S. fuelleborni. We provide the first molecular evidence of S. f. fuelleborni infection in humans in the Pacific. We also support that S. f. kellyi is a separate and distinct species of human infecting helminth. Renewed clinical and epidemiological investigations into infant strongyloidiasis in New Guinea using species-discriminatory molecular tools are indicated. Competing Interest Statement The authors have declared no competing interest. Funding Statement This work was partially funded by the National Health and Medical Research Council (NHMRC) Investigator Grant APP1194462. Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Ethics approval was obtained from the Papua New Guinea Institute of Medical Research Institutional Review Board (IRB# 1614) and the Papua New Guinea Medical Research Advisory Committee (approval no. 17.17). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Data Availability All data produced in the present work are contained in the manuscript