A California infant has died and at least 10 other people have been sickened in an outbreak of listeria food poisoning tied to ready-to-eat meat and poultry products that include chicken feet, duck neck, beef shank and pork hock, federal health officials reported Friday.

Yu Shang Food, Inc., of Spartanburg, South Carolina, has recalled more than 72,000 pounds of meat and poultry products tied to the outbreak, according to the U.S. Agriculture Department. Some products were initially recalled on Nov. 9.

The foods were shipped to retail locations nationwide and available online, and illnesses have been reported in four states. The problem was discovered in October after routine tests detected listeria in the foods and the production environment.

Of the 11 people sickened, nine were hospitalized, the U.S. Centers for Disease Control said. A California woman who was pregnant with twins was sickened and both infants died, the CDC said, but listeria was only found in a sample from one of the infants, so that child and the mother were included in the count but the other infant wasn’t.

Interviews with people who were sickened and laboratory findings pointed to the Yu Shang Food products.

Although the foods have been recalled, some may still be in consumers’ refrigerators or freezers. The products should be discarded or returned to the place of purchase. Refrigerators, containers and other surfaces that may have touched the foods should be cleaned and sanitized.

People get sick with listeria poisoning when they eat foods contaminated with the bacteria. Symptoms can be mild and include fever, muscle aches, nausea, vomiting and diarrhea. More serious illness can include headache, stiff neck, confusion, loss of balance and convulsions.

Listeria poisoning is tricky, because symptoms can start quickly, within a few hours or days after eating contaminated food. But they also can take weeks or up to three months to show up. Those most vulnerable to getting sick include the very young, people older than 65 and those with weakened immune systems or who are pregnant.

A different listeria outbreak tied to recalled Boar’s Head deli meats has ended, CDC officials said this week. That outbreak killed 10 people this summer and sickened dozens of others.