Custom Care Medical internist Dr. Frank Contacessa discusses the symptoms of an E. coli food infection on 'Varney & Co.

' The McDonald’s E. coli outbreak — which has now sickened more than 100 people, per reports — has spotlighted the risk of foodborne illnesses . The E.

coli infections were linked to contaminated onions served on McDonald's Quarter Pounder hamburgers, according to the U.S. Centers for Disease and Prevention (CDC), which continues to investigate the outbreak.

Many other foods could potentially transmit dangerous bacteria if stored or prepared in an unsafe manner, experts say, with an estimated 48 million people (one in six) affected each year, per the CDC. E. COLI OUTBREAK LINKED TO MCDONALD’S BURGERS: HOW TO SPOT THE SYMPTOMS Fox News Digital spoke with food safety experts about some of the most prevalent foodborne illnesses and how to prevent them.

1. E. coli E.

coli — officially known as Escherichia coli — is a type of bacterium found in the environment, foods and intestines of people and animals, according to the CDC. E. coli — officially known as Escherichia coli — is a type of bacterium found in the environment, foods and intestines of people and animals.

(iStock) The bacterium can spread via contaminated food or water or contact with animals, environments or other people, the same source stated. Eating meat that has not been cooked sufficiently to kill E. coli can cause infection, according to Mitzi D.

Baum, CEO of Stop Foodborne Illness.