From the web site of the United States Department of Agriculture (usda DOT gov):
“Is it dangerous to eat raw or undercooked ground beef?
Yes. Raw and undercooked meat may contain harmful bacteria. USDA recommends not eating or tasting raw or undercooked ground beef. To be sure all bacteria are destroyed, cook meat loaf, meatballs, and hamburgers to a safe minimum internal temperature of 160 °F (71.1 °C). Use a food thermometer to check that they have reached a safe internal temperature.”