Many people pass the symptoms off as stomach flu. All of us, at one time or other, have probably had a foodborne illness. Symptoms may be mild and disappear in a few hours or days. In severe cases, a stay in hospital may be needed. Death may even result, especially in the very young and the elderly.
Food poisoning occurs when food is eaten which contains enough germs (bacteria, bacterial toxins or viruses) to cause illness. The most common food poisoning bacteria and viruses are listed in Table 1.
Common food poisoning bacteria and viruses
|Name of Organism||Undercooked chicken, turkey, eggs, neat||6-72 hours||abdominal cramps, diarrhea, fever, chills, vomiting|
|Salmonella||Undercooked ground beef||12-72 hours||abdominal cramps, bloody diarrhea, fever, vomiting|
|E. coli 0157-H7 (causes 'hamburger disease')||Undercooked chicken or hamburger; unpasteurized milk; contaminated water||1-10 days||Nausea, cramps, headache, fever, diarrhea|
|Clostridium perfringens||Stews, meat pies, meat gravies held at improper temeratures||6-24 hours||Cramps, nausea, diarrhea|
|Staphylococcus aureus (toxin produced by this bacteria causes illness)||Cooked ham, potato salad; inadequately reheated leftovers||1-6 hours||Nausea, vomiting, abdominal cramps, diarrhea|
|Norwalk virus||Food contaminated by someone with the disease||10-50 hours||Nausea, vomiting, abdominal cramps, diarrhea, fever|
Once the food containing bacteria, viruses or toxins is eaten, the symptoms of foodborne illness do not occur right away. If the food poisoning is caused by toxins, the incubation period (the time between eating the food and getting sick) may be just a few hours.
If the food poisoning is caused by bacteria or viruses, however, it usually takes 12 to 48 hours for symptoms to develop. In some cases, it takes three or more days. This means that several meals may be eaten after the meal that caused you to become ill. We tend to blame food poisoning on the last meal but remember, it may have been caused by a meal you ate days before!
Foodborne illness usually occurs when food is handled so germs can grow and survive in it. These may include:
These cases describe some foodborne illness outbreaks and what went wrong.
A restaurant employee came to work while ill with diarrhea and did not wash her hands properly after going to the toilet. Salmonella bacteria on her hands likely contaminated the foods that she handled. Thirty-five people who ate at the restaurant became ill with Salmonella food poisoning. Nine were so ill that they were admitted to hospital.
While the food for a wedding banquet was being prepared, the two-year-old daughter of one of the cooks was sampling some food with her bare hands. The prepared food was delivered to the hall, and because of the insufficient refrigerator space, some was left on the counter for several hours. After the ceremony, the wedding guests went to the hall for the wedding banquet. Within four hours of the meal, many guests experienced severe nausea and vomiting. Some even passed out! Analysis of the food revealed that it contained large amounts of Staphylococcus aureus toxin, which causes an illness called staph intoxication. Further tests revealed that the cook’s child had the same strain of Staphylococcus aureus in her mouth as was found in the food. This outbreak was likely a result of both contamination of the food by the hands of the cook’s daughter, and later storage of the food within the temperature danger zone for several hours. The bacteria grew and toxins were produced.
In 1993, 583 people in the U.S. became ill with 'hamburger disease' after eating at the same restaurant. Four people died because of their illness. The likely cause of the outbreak was the undercooking of hamburger patties served by the restaurant.
Your local Public Health Inspector and other food inspectors are hard at work ensuring that the groceries you buy at the store and the meals you eat at your favorite restaurants are safe and wholesome. At home, however, you must assume the role of inspector. By following the rules for safe food handling listed below, you can prevent food-borne illness from becoming the uninvited guest at your dinner table.
Although Public Health Inspectors work with restaurant operators to maintain safety, they cannot be everywhere. If you eat out, you should be alert to ensure that restaurant staff are following the above procedures. Watch for:
If you notice any of these things, discuss your concerns with the restaurant management. If they are not dealt with to your satisfaction, consider dining elsewhere and calling your health department.
If you suspect that you or someone in your household has a food-borne illness:
You will likely be asked where and what you have eaten in the several days prior to your illness. The more detailed information you provide, the higher the chance that a health inspector can pinpoint the food that caused your illness.
More questions about foodborne illness? Contact your local Public Health Inspector.