There are reports of about two dozen illnesses so far in several states that could be linked to the outbreak. Symptoms of E. coli include dehydration and bloody diarrhea. In serious cases, people can succumb to kidney failure.
The USDA is offering tips on how to safely handle raw meat to avoid getting sick from bacteria like E. coli:
Don't simply rely on the meat's color to make sure your food is ready. Instead use a thermometer and only eat ground beef or hamburgers that have been cooked to an internal temperature of 160 degrees F.
Refrigerate raw meat within two hours of purchasing, or one hour on hot days when it's more than 90 degrees F. Also refrigerate cooked meat within two hours of cooking it.
Wash hands for at least 20 seconds with hot, soapy water before and after handling raw meat. Do the same for cutting boards, dishes and utensils used to prepare the meal. Keep raw meat away from food that won't be cooked.
Shoppers concerned about the recall can call the company's hotline at (800) 685-6328.
They can also receive more information from the USDA's Food Safety and Inspection Service at AskKaren.gov, or by calling USDA's hotline at 888-674-6854.
A full list of recalled beef products is also available here.
Last Wednesday, JBS Swift announced it would voluntarily recall about 41,280 pounds of beef products -- such as intact cuts of beef, as well as boxes of beef used for steaks and possibly further processed somewhere else -- that were produced on April 21 and 22. The company said those products were shipped to distributors and stores in 13 states.
On Sunday the USDA's food safety arm announced an expansion of that recall , flagging another 380,000 pounds of beef products for possible E. coli contamination.
The expansion includes questionable beef that was shipped both within the United States and abroad.
But beef is just one of many foods causing concern. On Monday, the Food and Drug Administration, which monitors safety of all foods except for meat, poultry and eggs, which are overseen by the USDA, found E. coli at the plant that makes Nestle Toll House cookie dough.
The FDA has also struggled this year to trace foods including tainted peanuts and pistachios.
Earlier this summer, Illinois meatpacker Valley Meats LLC of Coal Valley recalled nearly 96,000 pounds of ground beef due to possible E. coli contamination.
Last summer Nebraska Beef Ltd. of Omaha recalled more than 5 million pounds of beef due to an E. coli outbreak shortly before the FSIS issued its rule.
Today, Marler's advice is to keep frozen meat in the freezer and to hold off on cooking meat until you have more information about where it came from.
"This whole secretiveness of food safety is why we have the problem to begin with," Marler said. "Things need to be transparent and the public needs to know what's risky and what's not."
ABC News' Brian Hartman contributed to this report.