Foodborne Illness

Foodborne illness occurs when a person eats a food that contains harmful amounts of a bacteria, virus, parasite, toxin or chemical, and develops illness, usually with diarrhea and/or vomiting.  People sometimes refer to foodborne illness as “food poisoning”.  It can occur in any type of setting where food is served, not just at restaurants and picnics or parties, but also in the home.  Some of the more common foodborne pathogens include:

  •  Norovirus

  • Salmonella

  • Shigella

  • E. coli O157:H7

  • Campylobacter

  • Clostridium perfringens

  • Bacillus cereus

  • Staph (Staphylococcus aureus)

  • Listeria

Most of the organisms causing foodborne illness cannot be seen, smelled, or even tasted.  People can also get sick when chemicals such as lead and pesticides get into food.

Foodborne illness that occurs after consuming food or beverage from a food establishment in Orange County should be reported to HCA Environmental Health at 714-433-6418 or through an online Foodborne Illness Complaint.  All reports are confidential.

Healthcare Professionals

Frequently Asked Questions

How does foodborne illness occur?

Foodborne illness occurs when a person eats a food that contains harmful amounts of a bacteria, virus, parasite, toxin or chemical,  Food contamination can occur in the following ways:

  • Natural bacteria found in food are allowed to grow to harmful levels. This can happen when food is cooked or stored at the wrong temperature.
  • The cooking area is not kept clean(for example, when insects or rodents get into the kitchen area).
  • The cooking utensils are not cleaned properly. For example, a board used to cut raw meat is then used for foods eaten raw. This is called cross-contamination. Bacteria may also grow on wet, contaminated cloths and sponges (water may get rid of dirt you can see, but not bacteria).
  • Cooks or servers contaminate food as it is being cooked, prepared or served. This can happen when hands are not adequately washed, there are sores on the hands, or food handlers sneeze or cough into the food.

Will heating the food make it safe to eat?

Heating or re-heating contaminated foods to high temperatures will kill many organisms. But, there are some bacteria (e.g., Staph and Bacillus cereus) that make chemicals, also called toxins, that cannot be "killed" (inactivated) by heat.

What are the symptoms?

Many times foodborne illness goes unrecognized, or is thought to simply be a "stomach flu." Symptoms may occur within a few hours to days after eating contaminated food. It is often not the last thing eaten that makes a person sick. Symptoms may include:

  • Stomach cramps
  • Diarrhea
  • Fever
  • Nausea
  • Vomiting
  • Chills

The length of time a person is sick from a foodborne illness varies. Most people get better quickly, while some may have severe symptoms that can become serious. Sometimes diarrhea and vomiting can cause you to become dehydrated. You may need to see your doctor for your symptoms. Your doctor may need to do tests to find the cause of your illness.

What should I do if I think I have a foodborne illness?

If you think you are sick from foods that you bought at a store or ate in a restaurant or at a public event, call your local health department. If you live in Orange County, call:

County of Orange Health Care Agency
Environmental Health Division (EHD)

(714) 433-6418
All calls are confidential.

How can I prevent foodborne illness?

  • Food Safety Tips:

Food and Water Safety (for travelers)::


County of Orange Health Care Agency

Centers for Disease Control and Prevention (CDC)

US Department of Agriculture (USDA)

US Food and Drug Administration

  • FDA Center for Food Safety & Applied Nutrition: or 1-888-SAFEFOOD (1-888-723-3366)

Partnership for Food Safety Education, FightBAC!:

Gateway to Government Food Safety Information:

Last reviewed January 23, 2019