Escherichia coli O157:H7 (commonly referred to as E. coli O157) is a particularly dangerous strain of *E. coli* bacteria that can cause severe and life-threatening symptoms in humans. Here is why E. coli O157 can be deadly:

E. coli O157:H7 produces Shiga toxins (Stx), which are potent and harmful toxins capable of causing severe damage to the lining of the intestines and other organs. These toxins are the primary factors in the strain’s ability to cause serious illness.

Initial symptoms usually include severe stomach cramps, diarrhea (often bloody), and vomiting. Fever may be present but is usually not high.

In about 5–10% of E. coli O157 infections, the illness progresses to Hemolytic Uremic Syndrome (HUS), a life-threatening condition characterized by the destruction of red blood cells, acute kidney failure, and a shortage of platelets (thrombocytopenia). HUS is most commonly seen in young children and the elderly and can lead to long-term complications like kidney damage or neurological issues.

E. coli O157 is often spread through undercooked ground beef, unpasteurized milk or juice, raw produce, and contaminated water.

The strain is found in the intestines of cattle and can contaminate meat during slaughter. It can also spread through contact with animals or their environments, such as petting zoos.

E. coli O157:H7 requires ingestion of only a small number of bacteria to cause infection, increasing the likelihood of illness from even minor contamination.

The Shiga toxins can enter the bloodstream and target organs such as the kidneys, leading to serious complications.

Cooking food, especially ground beef, to an internal temperature of at least 160°F (71°C) to ensure bacteria and toxins are destroyed.

Using separate cutting boards and utensils for raw meats and avoiding contact between raw and ready-to-eat foods.

Washing hands, surfaces, and produce thoroughly. Also, avoiding unpasteurized milk and juices can help reduce the risk of infection.

Ensuring water sources are treated and safe from fecal contamination.

Through adherence to proper food safety practices and hygiene, risks associated with E. coli O157:H7 can be minimized significantly. Prompt medical attention is crucial for those showing severe symptoms to prevent complications like HUS.