According to the NHS website, some types of worms, external – caught in both the UK and abroad – can infect people in different ways.
Most worm infections are not serious though and can be easily treated with medicine.
The NHS suggests contacting your GP if they find a large worm, a piece of worm or worm eggs in their poo, have a red, itchy worm-shaped rash on your skin; or sickness, diarrhoea or a stomach ache for longer than two weeks.
Another potential symptom, as in Foy’s case, is losing weight for no discernible reason.
These infections are usually caught while travelling, and they can take a long time to show symptoms.
They can be contracted by touching objects or surfaces with worm eggs on them, and by eating or drinking something with baby worms in it – such as under-cooked beef, pork or freshwater fish.
Parasites can, in part, be avoided by thoroughly washing your hands, as well as any fruit and vegetables, before cooking and eating.
Other tips include drinking bottled or boiled water in high-risk areas, and deworming pets regularly.