All beef has a small chance of carrying a disease-causing E. coli strain such as O157:H7. Ground beef is much more likely to be contaminated than individual cuts of meat because of how the meat is processed.

A package of ground beef usually contains meat from many cattle. Therefore, the meat from one infected cow can contaminate many packages of ground beef. In addition, the contaminating bacteria are harder to kill in ground beef than in single cuts of meat. Bacteria can spread throughout ground beef, but they usually remain on the surface in single cuts of meat. When meat is cooked, surface temperatures more easily reach the 160°F (71.11°C) needed to destroy the bacteria. In ground beef, both the surface temperature and the internal temperature must reach 160°F (71.11°C).

When eating ground beef, make sure the meat is brown throughout. Any areas of pink may indicate that the meat did not reach high enough temperatures to destroy any potentially harmful bacteria.