A type of E. coli produces a Shiga toxin and causes disease. These types of bacteria are known as Shiga toxin-producing E. coli (STEC), or verocytotoxic E. coli (VTEC), or enterohemorrhagic E. coli (EHEC). E. coli O157: H7 is the most common STEC, responsible for several outbreaks. E. coli O157 was identified as a pathogen in 1982. Infection can be caused by people of any age. However, young children and the elderly are more likely to develop haemolytic uremic syndrome and severe illness. Symptoms of STEC include severe stomach cramps, diarrhoea, and vomiting. In some cases symptoms are accompanied by fever less than 38.5 C. People infected by STEC, generally, recover within 5 to 7 days, but in certain cases infections could develop into a severe or life-threatening disease. Approximately 5-10 percent infected with STEC develop the haemolytic uremic syndrome. Symptoms for haemolytic uremic syndrome include decreased urination, tiredness, and paleness in cheeks and inside lower eyelids. The kidneys may stop working and other serious complications may develop. Generally, recovery occurs within weeks, but a few cases result in death or permanent damage. There is an incubation period of 3 to 4 days after ingestion of STEC. In case of occurrence of the haemolytic uremic syndrome, it is generally after 7 days after first symptoms. Initial symptoms are often mild stomach pain or diarrhoea that worsens over time. STEC is commonly found in guts of goats, sheep, cattle, deer, and elk. Also, pigs and birds could spread STEC. Exposure to ETEC is generally by ingestion, such as consumption of food contaminated with STEC, consumption of raw milk, consumption of infected water, contact with animals, or contact with faeces. Foods, such as raw milk, unpasteurized apple cider, and cheese made from raw milk have been considered to be at high risk of contamination. Other .forms of exposure include swimming, touching animals, and/or lack of proper hygiene (National Center for Zoonotic, Vector-Borne, and Enteric Diseases, 2008).