By De Ann Davis, SVP, Science and Gustavo Reyes, Sr Manager, Data Analytics and Food Safety

Cantaloupes have been linked to multiple foodborne illness outbreaks in the U.S. and Canada over the last 30 years. There have been numerous U.S. Department of Agriculture (USDA) and Center for Produce Safety (CPS) research projects, rising investment in industry training programs, changes in harvest equipment design as well as improvements in field practices. Additionally, over the past two years, a revised national standard for the growing, harvesting and packing of cantaloupes was developed. The comment period for the final draft concluded earlier this summer, with the leadership of Western Growers, cantaloupe growers from across the U.S., academic experts and public health representatives.

In the Fall of 2023, a significant Salmonella foodborne illness outbreak occurred linked to the Malichita and Rudy brand cantaloupes grown in the Sonora region of Mexico. This outbreak was represented by 407 illnesses, 158 hospitalizations and six deaths, reported between October 15 and December 25. A recent research article by Canadian public health researchers, Megan Rose-Martel and Sandeep Tamber, reviewed several cantaloupe outbreaks, including the 2023 outbreak:

A similar number of outbreaks and cases was attributed to cantaloupes grown in both the United States (5 outbreaks, 800 cases) and Mexico (5 outbreaks, 776 cases). However, a disproportionate number of hospitalizations (255 vs 126) and deaths (17 vs 3) were linked to cantaloupes imported from Mexico, though the importance of Mexican imports reflects a large outbreak that occurred in 2023 and potentially the dominance of Mexico as a source of cantaloupe consumed in the United States.

Before we go any further, it is important to note that the domestic supply of cantaloupe as part of total market availability has been steadily decreasing, down about one-third over the last two decades, leaving imports to fill the supply gaps. Historically, Mexican cantaloupe was as high as 25 percent of the cantaloupes imported into the U.S; in 2024 it was down to 9.2 percent. Guatemala is rising as the major exporter of cantaloupes to the U.S. with more than 56 percent market share in 2024.

Back to a review of the 2023 outbreak, looking at the publicly available information on the FDA investigation, the following actions were noted:

• FDA and CDC completed traceback investigations in collaboration with Canadian authorities and identified the suppliers for contaminated cantaloupes. FDA had in place Import Alert 22-01, allowing for the detention without physical examination of cantaloupes from Mexico, except from firms on the “Green List.” This Import Alert was updated on April 14, 2025.
• Mexican health authorities temporarily closed a melon-packing plant in Sonora that was implicated in the outbreak (news article).
• The FDA did not provide information in its investigation report on the outbreak regarding on-site investigations at the farms where the cantaloupes were grown, food safety non-compliance findings at the Mexican packing plant that was temporarily closed, nor if the Foreign Supplier Verification Programs (FSVP) of the importers of the cantaloupes were inspected and any non-compliances noted.

In the Summer of 2022, there was a Salmonella outbreak linked to cantaloupe grown in southwest Indiana. This outbreak occurred between July and September and was represented by 87 illnesses, 32 hospitalizations and no deaths. It was identified by the FDA as part of a reoccurring pattern of outbreaks linked to melons from that region (2012, 2020, 2022).

Prior to the 2022 outbreak, Indiana supplied about 6 percent of U.S. cantaloupes. That estimate is now about 1 percent. The FDA outbreak investigation for the 2020 outbreak was detailed in journal article published in 2023. Here’s what the investigative response to the 2022 outbreak included:

• Traceback investigations led to three common farms and packing houses in a common region of Indiana. These sites were inspected by FDA inspection personnel.
• Environmental samples were collected of growing sites, packing houses and other equipment. Whole-genome sequencing (WGS) was completed for the pathogen positive samples and submitted to the NCBI database.
• In addition, the FDA launched a multi-year longitudinal study in partnership with Purdue University and regional agricultural stakeholders to better understand potential pathogen ecology in this agricultural region.

When we compare what we understand as the agency’s response to both outbreaks, there is quite a difference in how the agency utilized its authorized regulatory tools to investigate, communicate and prevent reoccurrence of future outbreaks at the domestic farms versus the farms and packing houses in Mexico.

The domestic growers in Indiana experienced on-site inspections and environmental swabbing for pathogens throughout their operations. The producers in the region are now cooperating with the FDA in an environmental study of pathogen transmission, and those still growing cantaloupes will need to invest money to address findings. These producers will also need to continuously manage the land value risks associated with the pathogen WGS now linked to their farms. As I mentioned earlier, it’s worth noting that production in the southwest region of Indiana now represents only 1 percent of the cantaloupe market in 2024, down from 6 percent prior to the outbreaks.

The Mexican growers in the Sonora region, a region also known for repeated melon-related outbreaks, does not appear to have to manage these same economic circumstances and risks. FDA and Servicio Nacional de Sanidad, Inocuidad y Calidad Agroalimentaria (SENASICA) have a Memorandum of Understanding (MOU) for the purpose of establishing a system that increases the likelihood that cantaloupes from Mexico offered for import into the U.S. complies with U.S. law. The MOU lays out a tiering scale for firms based on whether firms (farms) have been implicated in an Outbreak, had shipments test positive for Salmonella or neither.

In brief, the firm’s handling under Import Alert 22-01 is determined by its tier and if SENASICA has certified the firm. Under the current Import Alert, some firms are greenlit or exempted from the Import Alert 22-01.

Based on available information, it’s unclear why the FDA did not impose additional regulatory measures on Mexican cantaloupe imports, such as the use of its Import Certification Authority, despite the region’s history and the severity of the outbreak, similar to actions recently taken for shrimp and spices from Indonesia. It did, though, add additional record reviews at the border for “yellow light” firms.

Another consideration would have been to ensure isolates and WGS from cantaloupes of the Sonoran region are provided to the National Center for Biotechnology Information (NCBI) database when they test positive for Salmonella at the border (perhaps this is being done). Capturing these paired pathogen WGS would help to quickly narrow investigations earlier in a foodborne illness outbreak investigation.

Cantaloupe imported from Mexico still represent about 9 percent of the U.S. market, having not experienced a similar almost complete loss of market share as southwest Indiana following that region’s outbreak. Assuring a strong and focused prevention regulatory system for these imported Mexican cantaloupes seems warranted as we focus on improving consumer consumption of fresh produce.

To prevent the recurrence of foodborne illnesses, our public health authorities must investigate and respond equally to domestic and foreign farms following an outbreak or significant food safety finding. The agency cannot potentially provide an economic or regulatory advantage to foreign farms, especially those in a region known to be associated with outbreaks. Foreign farms and their supply chains need to invest in the same necessary food safety improvements and FSMA compliance costs as expected of domestic operations and necessary for food safety. FDA should assure that foreign, including Mexican cantaloupe growers, have completed these investments in testing, equipment, training and field practices and that these changes are reflected in the records required for import. After all, Mexico still supplies a strong share of the U.S. market, and we import over 40-45 percent of all our cantaloupes.

We must hold foreign fresh fruit and vegetable supply chains equally accountable to grow, pack and ship safely and consistent with the FSMA regulations. This requires equitable enforcement, accountability and consequences from the FDA for foreign farms, their supply chains and importers.