Ground beef and O157:H7

One million pounds of ground beef are being recalled due potential contamination with  E. coli O157:H7. Approximately, 7 people have fallen ill so far.

The reason why ground beef is so problematic is that people do not fully cook their ground beef. The bacteria present on the side of beef after processing gets ground into the entire batch. This is different from a steak. The surface of the steak  may be covered in bacteria but those are incinerated while cooking. The interior of the steak is not contaminated, so eating a rare steak is acceptable.

However, the interior of a hamburger is a lovely place for growing bacteria. If the hamburger is not cooked to an internal temperature of 160°F, the living bacteria in the middle of the burger are consumed, get into your intestine and start replicating.

After establishing their niche in your gut, this specific strain of E. coli (identified by its capsule and flagella) starts producing a toxin that can cause disease, such as gastroenteritis, but more specifically Hemolytic Uremic Syndrome (HUS). The secreted toxin  targets and destroys red blood cells, which can then shut down kidney function. This especially targets children under the age of 5 and the elderly:

More than half of children with HUS develop acute kidney failure. With kidney failure, the child’s urine output decreases. The urine may also appear red. Urine formation slows because the damaged red blood cells clog the tiny blood vessels in the kidneys, making them work harder to remove wastes and extra fluid from the blood. The body’s inability to rid itself of excess fluid and wastes may in turn cause high blood pressure or swelling of the face, hands, feet, or entire body.

The problem is that some individuals insist on eating (and feeding their children) undercooked hamburgers, which they say taste better. These people generally like to cook, consider themselves foodies, and pride themselves on their grill mastery. According to the article and to the U.S. Department of Agriculture’s Food Safety and Inspection Service (FSIS):

The only way to be sure ground beef is cooked to a high enough temperature to kill harmful bacteria is to use a thermometer to measure the internal temperature.

And yes, most of the time we see the contaminated meat coming from large food processing plants, but that doesn’t mean that your locally grown beef may not be also contaminated with the same organisms. Infections in cattle are subclinical, so the cattle do not display any outward symptoms that  they carry this strain of bacteria. In 2006, there was a large recall of organic beef that was contaminated with O157:H7.

So, foodies, beware. That rare hamburger could be a source of a lot more than just bragging rights.

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