Toxocara canis and T. cati are zoonotic roundworm parasites which reside in the intestines of infected dogs, cats and foxes. Large numbers of Toxocara eggs are shed in the faeces of infected animals, which contaminate the environment. If humans ingest Toxocara spp. eggs or larvae, it can lead to toxocariasis which can result in allergic, ophthalmic and neurological disorders.

It is widely accepted that inadvertent ingestion of soil can result in toxocariasis, but given that soil is a common contaminant of vegetables, and pasture grazing animals can become infected resulting in Toxocara larvae in meat, the pathway to food-borne transmission appears wide open. However, this route of infection has received relatively little research attention.

In this study, vegetable produce and meat tissues were evaluated for the presence of Toxocara spp., with eggs recovered from allotment-grown lettuce and the DNA of both

T. canis and T. cati detected on field-grown spinach. Whilst no larvae were recovered from meat samples, anti-Toxocara spp. antibodies were detected in tissue exudates, confirming exposure of animals to this parasite from agricultural environments.

Using this experimental data, mathematical models were developed to produce quantified risk estimates for Toxocara spp. transmission to humans via food, which indicated a low infection risk from consuming unwashed leafy vegetables and undercooked meat. This study paves the way to future research to build upon these findings, informing public health policy and food safety measures.

Overall, this work has confirmed that Toxocara spp. is present in the UK food chain and provided a modelling framework for future risk-assessment studies. Whilst the estimated risk of transmission of Toxocara spp. via leafy vegetables and meat is low, given the potentially severe consequences, mitigation strategies to reduce environmental contamination with Toxocara spp., and consumer intervention around correct preparation of food is warranted to protect public health.