Blastocystosis is a parasitic disease like Trichinosis, though this one is caused by tiny single celled organisms called Blastocystis. Blastocystosis can cause agonising joint pain, fevers and intestinal distress. e disease is even thought to be a contributing factor to the development of IBS. Unlike most of the food-borne illnesses on this list, research suggests that the biggest risk factor for Bloastocystosis is the consumption of dirty or unwashed plant matter, as the parasites are often transmitted through water contaminated with infected human or animal feces – unwashed leafy vegetables are thought to be a risk factor.