Produce Spotlight: Strawberries

Worker training is one of the best ways to help prevent foodborne illness. Read more on how strawberries have been linked to hepatitis A in the past, as well as some factors to consider in your Agricultural Water Assessment if you grow strawberries.

This monthly crop spotlight is a great reminder that although historically not every crop has been linked to foodborne illness outbreaks, risks are present on every growing landscape and still need to be considered and assessed.

Hepatitis A Outbreak: Importance of Worker Training

In 2022 frozen strawberries were linked to a hepatitis A outbreak that spanned multiple years due to the shelf life of frozen fruit. 18 people reported falling ill after eating frozen strawberries, with 13 being hospitalized. Hepatitis A is a highly contagious virus that can cause mild illness lasting a few weeks to severe illness that can last months and even end with liver failure and death for people with weakened immune systems.

While some hepatitis A infections are from unknown causes and from being in close contact with an infected person, other infections are caused by eating or drinking contaminated food or water. This contamination occurs when someone handling food does not practice appropriate hand washing hygiene after using the restroom.

In this outbreak case the affected strawberries were traced back to a common supplier meaning someone handling the strawberries early in the supply chain was most likely sick with hepatitis A, transferred the virus to the strawberries, and since freezing is not a true kill-step, the virus was able to persist on the strawberries, making others sick.

It is important to remember that the Produce Safety Rule (PSR) requires that at least annually workers must be trained in principles of food safety and the importance of health and hygiene, including recognizing symptoms of a health condition that could result in contamination of produce or food contact surfaces. In the PSR Draft Guidance, applicable health conditions to be aware of are those that can be passed from one person to another and can include diarrhea, vomiting, abdominal cramps, sore throat with fever, jaundice (yellowing of the skin or eyes), and open sores or wounds. If a worker has any of these symptoms, they should notify their supervisor and not handle produce or come into contact with food contact surfaces until the health condition no longer presents a risk to public health.

Strawberries and the Agricultural Water Assessment (AWA)

The AWA is meant to help identify factors present on the farm related to pre-harvest agricultural water that could introduce contamination onto produce or food contact surfaces.

Water system: Is groundwater (well) or surface water (pond, stream, etc.) used (municipal water is exempt from the AWA), where is the water source located, can animals access the water source, is the water source used for anything else? How is the water distributed?
Water practices: Are the strawberries irrigated with drip under plastic, overhead with sprinkler, or another way? Is water used for frost protection? Is there a time interval before the last water use on the strawberries and harvest?
Crop characteristics: Strawberries are traditionally grown on the ground and are a soft fruit with achenes on the surface that could make them more prone to internalization of foodborne pathogens in the fruit’s tissues, potential bacterial and fungal contamination from soil-borne pathogens, as well as water contamination.
Environmental Conditions: Is the field prone to flooding that could impact crop or water system?
Other relevant factors: Is the water source being tested? Those results can also help to determine if the water is safe and of adequate sanitary condition for its intended use.

Conclusion

This month’s strawberry highlight is a great reminder that there is no crop exempt from outbreaks, it really comes down to the practices in place on the farm that are used to reduce risk. Like Morgan said in last month’s crop spotlight: prevention is key! Completing an agricultural water assessment at least annually and having an effective worker training program are two ways growers can help protect public health and their workers, as well as their farms from outbreaks and recalls.

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Article by Allissa Conley, Produce Safety Technician