they get worms if they eat infected and not well washed vegetables (like salads ...), that contains worm eggs.

.....and from contact with grubby children, with unwashed toilet hands, from nail-biting, self-infection (as these gut-dwellers are in us all the time) sometimes an excess of sugar can set that up. The worms come out of your bum at night, and lay eggs, we sctach unwittingly or knowingly, and the tiny eggs are transported from our fingernails to our mouths and the mouths of others. Yay ! the worms take over. They are gross, but treatable. Eat loads of grated carrot, drink lemon juice and water, chew pumpkin seeds and sunflower seeds, chew 4-5 lemon seeds, and add raw garlic to your diet. The worms are repelled from your gut, and drawn out with the carrot fibre, and poisoned by the lemon seeds, and the rough seeds help too.

if you eat a worm and its still alive