News about foodborne disease outbreaks is common, with stories about illness and food recalls as the result of contaminated food. Cookie dough, raw shellfish, and many other products can be breeding grounds for bacteria such as Salmonella, Listeria, and E. coli. The Food and Drug Administration (FDA) and Department of Agriculture (USDA) place strict regulations on the food industry to improve food safety. This greatly reduces the number of food poisoning cases, but they cannot prevent all outbreaks.
When an outbreak occurs, the Centers for Disease Control and Prevention (CDC) play a key role in minimizing its impact. That’s because these agencies work behind the scenes, continuously monitoring outbreaks and quick acting when outbreaks occur to prevent their spread. PulseNet is just one example of CDC’s surveillance functions to protect the public’s health.
What Is a Foodborne Illness Outbreak?
A foodborne illness is an infection from a type of bacteria, virus, or parasite where the pathogen is transmitted. Foodborne illnesses are also known as foodborne diseases, foodborne infections, or food poisoning. An outbreak is simply an occurrence of two or more people being infected with the same pathogen from the same source.
The Most Common Causes of Foodborne Illness
More than 250 types of pathogens are known to cause foodborne disease outbreaks. The biggest cause of foodborne illness is Norovirus. The other top pathogen species are the following.
- Clostridium perfringens
- Staphylococcus aureus
Raw foods, such as raw shellfish, poultry, eggs, and unpasteurized milk, are most likely to cause food poisoning. Foods that contain components from many different sources, such as a hamburger made with ground beef from multiple cows, are riskier. Raw fruits and vegetables and unpasteurized juice can be contaminated with pathogens that are in the soil that contacts them. Nuts, cheeses, and prepared meats have also been linked to outbreaks.
The Impact of Foodborne Illness
Approximately one out of six Americans get food poisoning each year, although this number is an estimate because most cases of foodborne disease go unreported. People with food poisoning may think they have a 24-hour “flu” because of symptoms such as stomach pain, vomiting, and diarrhea. They may not go to a doctor or get tested for foodborne illness because their symptoms go away on their own.
However, some cases of foodborne illness can be fatal or require hospitalization for conditions such as severe dehydration or kidney failure. Children, older adults, and individuals with compromised immune systems are most susceptible. About 1,000 outbreaks are investigated each year.
Role of Surveillance
Surveillance systems monitor trends so they can quickly detect anything that happens out of the ordinary. Quickly identifying the source of a foodborne outbreak can lead to quick action, such as pulling a product from supermarket shelves or getting an ingredient out of the food supply. It can also lead to new safety regulations or better oversight if investigators find that the outbreak was preventable. PulseNet is one of the CDC’s national surveillance system.
PulseNet: “Pulse” for Early Outbreak Detection
PulseNet began in 1996 and now has 87 laboratories with at least one in each state. It uses a standardized technique called pulsed-field gel electrophoresis (PFGE), which allows investigators to determine whether a pathogen from one case might match pathogens causing other cases of foodborne illness. This allows for detection of potential outbreaks. PulseNet detects 10 to 15 widespread multi-state outbreaks and another 250 smaller multi-state outbreaks annually.
How PulseNet Works
Doctors order a lab sample when they suspect foodborne illness in their patients order a lab sample. The PFGE technique can identify the strain of pathogen, and results are sent to a public health lab within PulseNet. Microbiologists and epidemiologists interview the patient to discover which food may have caused the disease. After matching that food to other patients with the same disease, they would know which food is causing the trouble.
How Consumers Can Fight Foodborne Illnesses
Consumers can stay safe in everyday life by following the advice from the federal government. These are the four simple steps.
- Clean foods before eating them.
- Separate raw from cooked foods. For example, do not let raw chicken touch ready-to-serve salad.
- Cook raw foods until they are thoroughly cooked to the temperature stated on the package.
- Chill foods quickly after serving them.
Watch the news for announcements about food recalls and foodborne illnesses in your area. News stories generally publish the lot numbers, retailers and specified date ranges on the products that may have been on the shelves of retail stores.
Foodborne illness strikes millions annually in the U.S., but the CDC is working to reduce the impact. Systems such as PulseNet allow for early detection and action to stop the spread.