Foodborne illness outbreaks are a scary ordeal. People’s lives could be in danger and your food establishment could risk devastating consequences. Once a foodborne illness outbreak is suspected, you are required to report it to your local regulatory authority. Reporting an outbreak is only the first step in the investigation process. Expect to go through some combination of the following steps during an investigation of a foodborne illness outbreak.
- Detect and Report Possible Outbreak
Always keep a record of customers that call in to complain about foodborne illness symptoms. If someone calls in with a complaint, use this foodborne illness questionnaire to record their complaint. If you receive several complaints about people suffering from foodborne illness symptoms, you should start to consider a possible outbreak. Since a foodborne illness outbreak is defined as two or more people suffering from a similar illness, this can happen very quickly.
Once you suspect a possible outbreak, you should immediately stop operating and notify your regulatory authority. After notifying the regulatory authority, continue to track and record complaints as you receive them.
- Find Cases in Outbreak
When an outbreak is suspected, it is important to find all the people that are affected. Your regulatory authority will probably develop a case definition to help identify which people should be included as part of the outbreak. This definition might include symptoms of an illness, a pathogen (if known), a time range for the onset of the illness, or a geographic range. Investigators from your regulatory authority will try to find as many people that meet this case definition as possible. It is likely that not everyone that gets sick will call in to complain to your facility. The investigators may have to use different resources to find everyone involved.
- Interview and Hypothesize
After finding a group of your customers that share similar symptoms, the investigators will interview and question them. The investigators need to find out what food caused the illness. The questions they ask will depend on how much they already know. Most likely, they will review your menu and ask the customers what they ate. If there is a common food the customers ate, that food is most likely the suspect. If the customers all ate around the same time, a sick food worker might have contributed to transmitting the illness. The goal of these interviews is to come up with hypotheses about which illness it is and what food it came from.
- Analyze and Test Hypotheses
There are two main methods of testing—epidemiologic studies and food testing. Epidemiologic studies use statistics to study patterns of illnesses. This is really useful for when investigators are studying a big population. However, since they will know it came from your establishment, they will most likely focus on food testing. Food testing includes gathering samples of food and testing the samples in a lab to discover pathogens on the food. This testing can either be extremely useful or very confusing. The testing might not be helpful if the food in question had a short shelf life and is no longer available. Or if the pathogen was only in a portion of the food, the test might come up negative. Clearly, this can be a frustrating step in the investigation.
Sometimes the investigators will not find a link between a specific food and illness. If this is the case, that doesn’t mean the illness wasn’t foodborne. It just means the source hasn’t been determined yet. If the outbreak is over, the source is declared unknown. But if people are still reporting illness, the investigation must continue and more information must be gathered.
- Find Point of Contamination
If a source is identified, the next step is to find out how it became contaminated. Your regulatory authority will probably want to interview all staff members involved in preparing the food that caused the outbreak. It is in your best interest to cooperate and make sure all of your employees involved answer honestly. Some employees may feel embarrassed if they made a mistake. Be sure to stress to them that it is important to find out how the food became contaminated so that future customers won’t get sick. If the investigators can’t find a way the food was contaminated in your facility, there’s a chance it was contaminated somewhere before you received it. You will need to give them the contact information for your suppliers. Giving the regulatory authority this information is the quickest way to deal with and solve the cause of an outbreak.
- Control Outbreak
Once all of the pieces of the puzzle have been put together, the situation must be controlled. If the contaminated food or the person or item that contaminated the food is still in your facility, something must be done. Controls must be put in place to prevent the outbreak from happening again. This might include changing cleaning procedures, recalling food items, throwing away food, or even changing suppliers.
- Decide If Outbreak Is Over
The hope is that once the food that caused the illness is found, the outbreak will be over. This isn’t always the case. If you are part of a chain food facility, other facilities might also be affected. Or if the food was contaminated at the supplier’s facility, other food establishments might be affected. There’s also a chance that the food source was not completely controlled and more illnesses will be reported. Your local regulatory authority must continue to investigate until they are sure that the outbreak is over.
Every foodborne illness investigation is unique, and these steps might be done in a different order. The most important thing you can do is to stay calm throughout the process and be ready to answer any questions so you can help determine the cause of the illness. Remember, your number one priority is to keep your customers safe. Work honestly and directly with your regulatory authority to solve the investigation as quickly as possible. For more information on all of these steps, refer to this article from the CDC.