2022 Salmonella Outbreak Linked to Cantaloupe

Posted in Our Blog,Outbreaks & Recalls on June 7, 2023

The kids are hearing the school bell ring for the last time this year. People are planning vacations. Picnics and fresh fruit are on the menu.

 

Melons are especially popular this time of year. The refreshing juicy fruit provides a nice respite from the summer sun. It is almost a tradition. Or it should be.

 

For that reason, the United States Food and Drug Administration (FDA) has been working in the background all year to get to the bottom of what really caused last year’s multi-state outbreak in an effort to prevent it from happening again this year.

 

FDA Releases Report

Last month, the FDA released a report, “Factors Potentially Contributing to the Contamination of Cantaloupe Implicated in the Outbreak of Salmonella typhimurium During the Summer of 2022”. It investigates the multi-state outbreak that caused 88 reported illnesses and 32 hospitalizations between July and September 2022 in the United States.

 

This report was a partnership between the FDA, The U.S. Centers for Disease Control and Prevention (CDC), as well as state and local partners that linked the outbreak to cantaloupes grown in Southwest Indiana through epidemiology and other traceback activities during the summer of 2022.

 

The Investigation

 

The FDA, CDC, and state partners came together in August 2022 for a joint investigation into a multi-state outbreak of Salmonella Typhimurium linked to cantaloupe. Here is how it all went down.

 

CDC Discovers Related Cases and Common Food

That August, the CDC started noticing a multistate cluster (Georgia, Illinois, Indiana, Iowa, Kentucky, Michigan, Minnesota, Montana, Ohio, South Carolina, and Wisconsin) of Salmonella Typhimurium illnesses with the same genetic makeup. These cases were geographically distributed in the upper Midwest United States and had strong traceback data for a common food – melons.

 

Supply Chain Investigation

The FDA identified 11 points along the supply chain that these melons may have connected. A common packing house was indicated in 8 of these points of contact. While a single farm could not be identified from this data, it did narrow it down to 3.

 

Strains Were Compared to Soil Samples from a Previous Outbreak

The outbreak strain was compared to soil sample from a 2020 outbreak investigation in Indiana. The strains, while not an exact match, were similar.

 

This prompted the FDA to take soil samples from those farms again. Environmental samples from 3 Indiana farms tested positive for Salmonella bacteria. These samples, along with their common packinghouse, and nearby public lands were analyzed. The results were puzzling.

 

The Strains Didn’t Match

Laboratory analysis generated some confusing results. The strains did not match. The 2022 soil samples were not a match to the 2022 outbreak strain either.

 

While this investigation did not directly link the farms to the outbreak, it did indicate the presence of Salmonella on the farm, post-harvest, and in off-farm environments.

 

No Recall

Unfortunately, by the time the potential farms were identified, the implicated products were no longer on the market and likely already consumed or discarded. As a result, there were no recalls or public warning.

 

This after-action investigation and subsequent report were designed to help growers and those in the supply chain take steps to prevent another outbreak for this growing season.

 

FDA Releases Recommendations and Requirements

 

Based on good growing practices and observations during the investigation about the farms’ and packinghouse’s procedures, the FDA released a series of recommendations and requirements for growers and downline activities for melons and similar produce.

 

Review Current Conditions and Practices

Growers and related firms (such as packinghouses) are to review their current conditions and practices to determine whether they meet safety standards or should be modified as needed.

 

Take a Look at Previous Land Use

Growers are recommended to look into what the land was used for prior to the farming season. Doing so can help address potential pathogen sources that could affect their operations. For example, was this land used to raise cattle or poultry? What was the land used for?

 

Testing for pathogens may be a good idea. If risk is too high, other land should be considered instead.

 

Consider Adjacent and Nearby Land Usage

While farmers can’t control what goes on in areas outside of their land, considering the nearby land usage is still important. Farms may be able to mitigate certain risks associated with irrigation or runoff from feedlots or poultry farms that might impact their crops.

 

Incorporate Testing in Pre- and/or Pos-Harvest Periods

Environmental sampling is an easy way for farms to get ahead of an outbreak situation. Tools such as pre- or post-harvest sampling preventative measures could benefit the farm in the long run.

 

Poultry Manure as Fertilizer

According to the FDA, while poultry manure is valued as an effective fertilizer, it can harbor Salmonella. This type of fertilizer should be treated with a validated and verified process to reduce the spread of pathogens. Certain composting times/temperatures can be effective at mitigating that risk.

 

Keep Food Contact Surfaces Clean

The FDA recommends farms and packinghouses keep food contact surfaces clean. Inspecting, maintaining, cleaning, and sanitizing food contact surfaces frequently and as needed can help protect against contamination.

 

The correct use of EPA approved sanitizing and cleaning products should be employed as needed.

 

Standard Operating Procedures

Standard Operating Procedures, or SOP’s provide clear communication on what should be done, how, and when it should be done. Creating, following, and making sure all appropriate people are updated on any changes is key – especially when it comes to food safety practices.

 

Improve Traceability

Traceability is a term that describes the ability to trace back each product from the field to the consumer’s table. Electronic records and standardization of these records helps expedite potential recalls. The faster contaminated product is removed from circulation, the fewer people potentially impacted by illness associated with the event.

 

This traceability should not stop at the farm. True traceability would track the product from the grower, through the shipping processes, manufacturers, and even onto retailers. In essence, the entire supply chain.

 

Continued Efforts

 

The FDA is continuing cooperation with the Indiana State Department of Health to increase awareness in the area’s melon growing industry of the pathogenic environmental strains in the region to develop and promote risk reduction strategies related to melons.

 

It will take a group effort.

 

“Food safety is a shared responsibility that involves food producers, distributors, manufacturers, retailers, and regulators. Recognizing the interconnection between people, animals, plants, and their shared environment when it comes to public health outcomes, we encourage collaboration among various groups in the broader agricultural community (i.e., produce growers, state government, and academia) to address this issue.”

 

Make Food Safe will continue to keep a watchful eye on this and other food safety information. Check back often for information on outbreaks, recalls, as well as general safety tips and information.

By: Heather Van Tassell