Authors

L Woolfe¹; M Betson¹; AH van Vliet¹;  ¹ University of Surrey, UK

Discussion

Ascaris is a large soil-transmitted helminth that results in serious morbidity, particularly in lower and middle-income counties. It is a ubiquitous pathogen of both humans (Ascaris lumbricoides) and swine (Ascaris suum). Ascaris affects over 700 million people worldwide, resulting in childhood stunting and developmental delays. It is also the most prevalent nematode in pigs, resulting in significant economic losses. Poor hygiene practices, contact with infected pigs, the use of sewage sludge and inadequate preparation of fruits and vegetables before being consumed, propagate Ascaris spread. Cross infections between humans and pigs and hybridisation events between A. lumbricoides and A. suum have been reported; although, the full evolutionary relationship between the two is still unknown, with continued debate on whether these are in fact the same species.

The World Health Organisation aims to eliminate soil transmitted helminths as a health problem by 2030; however, the threat of treatment resistance is a growing concern. Therefore, it is imperative to elucidate the evolutionary relationships between A. lumbricoides and A. suum, as well as understand the interplay between humans, pigs, and the environment to help guide and maintain effective control measures in endemic regions.

This project aims to generate new whole-genome data for Ascaris samples from different hosts, regions and countries– using Illumina short-read and Oxford Nanopore MinION long-read sequencing. These data will be used to shed light on i) Ascaris transmission dynamics ii) evolutionary origin through the identification geographical differences and iii) genome response to selection pressures. We also aim to create a new multi-locus typing scheme to discriminate parasite stains in faecal and environmental samples, and field test this scheme with samples from the UK and the Philippines.