The food is transported over great distances, sometimes without adequate refrigeration. While those bacteria can make you sick for several days, usually with diarrhea and fever, they rarely cause any lasting or serious harm to most people. The risk is much greater, however, in pregnant women, young children, elderly individuals and those with weakened immunity, such as AIDS or chemotherapy patients. Government and industry are taking a wide range of steps to keep pathogens out of the food chain in the first place, as well they should. But at least for now, the main burden falls on you, the consumer.
Most cuts of beef are quite safe to eat.
That's because any bacterial contamination that may have resulted from butchering is confined to the surface, which almost always gets cooked to germ-killing temperatures. But when beef is ground up, the bacteria can end up in the center of the meat, which may not get fully cooked. In restaurants, high-risk individuals should avoid burgers altogether, or order them at least medium well. Cooking these products at the plant should kill all bacteria, but recent, deadly outbreaks of a strain called Listeria monocytogenes demonstrate that there can be recontamination after cooking. Unlike other potentially dangerous bacteria, listeria appears to cause serious illness almost exclusively in high-risk individuals.