While meat-loving foodies may swoon for steak tartare or yukhoe, eating raw beef dishes like these or even rare cooked beef can potentially make you very sick. Food poisoning can occur if the raw or undercooked beef is contaminated with a disease-causing organism. Cooking beef steaks or roasts to an internal temperature of 145 F followed by resting the meat for 3 minutes before eating kills most of these germs. Ground beef must be cooked to an internal temperature of 160 F.
E. Coli Food Poisoning
The bacterial group Escherichia coli (E. coli) includes hundreds of strains. Several strains normally inhabit the intestines of cattle and humans, and most are harmless. However, a few E. coli strains found in cattle can cause food poisoning in humans if the meat is accidentally contaminated. E. coli O157:H7 is the most concerning strain responsible for human food poisoning. This and other disease-causing E. coli strains can cause food poisoning in people who eat raw or undercooked beef.
Symptoms typically develop 3 to 5 days after eating the contaminated food, with abdominal pain and watery diarrhea predominating. Fever is usually absent. Most people recover in 7 to 10 days. However, 5 to 10 percent of people with E. coli O157:H7 develop a potentially life-threatening complication known as hemolytic uremic syndrome. The condition occurs when bacterial toxins trigger destruction of circulating red blood cells and sudden kidney failure.
Eating raw or undercooked beef can lead to salmonellosis, an infection caused by Salmonella bacteria. The bacteria can inhabit the digestive tract of cattle without causing illness in the animals. Fever, abdominal cramps and watery diarrhea typically occur 12 to 72 hours after ingesting Salmonella-contaminated food. Symptoms usually persist for 4 to 7 days, although normal bowel habits may not return for several months in some people.
The Centers for Disease Control and Prevention reports that up to 8 percent of people with Salmonella food poisoning develop invasive disease, in which the bacteria spreads from the intestines to other parts of the body, such as the bloodstream, joints or bones. Invasive salmonellosis can be life-threatening.
Campylobacter bacteria commonly inhabits the digestive tract of cattle and poultry, and can contaminate the meat and lead to food poisoning unless properly cooked. Most cases of Campylobacter food poisoning, known as campylobacteriosis, are caused by Campylobacter jejuni. Symptoms typically begin 2 to 4 days after ingesting the bacteria and include abdominal cramps, diarrhea and fever. Nausea and vomiting may also occur. Most people recover within 7 to 10 days.
Campylobacter can spread to the bloodstream, especially in people with a weakened immune system. This development can be potentially life-threatening. CDC reports that approximately 1 out of every 1,000 people develop a condition called Guillain-Barre syndrome in the weeks following a bout of campylobacteriosis. Guillain-Barre syndrome causes temporary paralysis, which can persist for several weeks to months.
The bacteria Listeria monocytogenes is found in cattle, poultry and the soil. Eating raw or undercooked beef is a potential source of Listeria infection. In healthy adults who have not reached their senior years, ingestion of a relatively large amount of Listeria bacteria can lead to fever, watery diarrhea, nausea, headache and body aches within 24 hours. Symptoms in these people usually improve in a few days. However, certain groups are at high risk for invasive disease, or listeriosis. High-risk groups include pregnant women, newborns, adults older than 65, and people with a weakened or suppressed immune system.
Flu-like symptoms typically occur in pregnant women with listeriosis, which can lead to miscarriage, preterm delivery, stillbirth or infection of the baby. Other high-risk groups who develop listeriosis can exhibit a variety of symptoms, depending on the area of the body infected with the bacteria. Invasion of the bloodstream and nervous system are particularly common and can be life-threatening. Although uncommon, even people not in a high-risk group sometime develop listeriosis.
Other Foodborne Infections
Other bacteria can potentially contaminate beef and cause food poisoning if the meat is eaten raw. Examples include Shigella and Staphylococcus aureus. Viruses, such as the hepatitis A virus and norovirus, can also be contracted from contaminated, raw meat. Eating undercooked or raw beef also poses a risk for parasitic infections, such as beef tapeworm and giardiasis. Parasitic infections are a greater risk when eating raw beef in developing countries that may have inconsistent or substandard food-quality standards or sanitation.
Warnings and Precautions
Eating raw beef poses potentially serious health risks, particularly for young children, pregnant women, seniors and people with a chronic illness or weakened immune system -- such as those with HIV/AIDS or being treated for cancer, and organ transplant recipients. However, even otherwise healthy people can become severely ill from food poisoning. While most people recover from food poisoning, the Centers for Disease Control and Prevention estimates that approximately 2,600 Americans die of foodborne illnesses each year.
If you decide to eat raw beef, seek immediate medical care if you develop any signs or symptoms of a foodborne illness.
Reviewed and revised by: Tina M. St. John, M.D.