Multiple State Salmonella Outbreaks due to Papayas from Mexico is over: What have we Learn?

According to reports by the CDC and the FDA, this summer outbreaks due to Salmonella-contaminated Maradol papayas imported from Mexico infected 251 people in 25 states. 79 of the infected people were hospitalized, and two deaths were reported.
The outbreak strains included: Salmonella Thompson (144), Kiambu (54), Anatum (20), Agona (12), Gaminara (7), Urbana (7), Newport & Infantis (4), and Senftenberg (3). Four brands of Maradol papayas were implicated:
  • Caribeña brand was distributed by Grande Produce between July 10 and 19.
  • Cavi distributed to wholesalers in New York, Connecticut, and New Jersey from July 16-19 and available to consumers until July 31. The product was distributed by distributed by Agroson’s.
  • Valery brand was distributed by Freshtex Produce, from July 10 to 13.
  • Fruta Selectas brand distributed by Bravo Produce to markets in the state of California between August 10 and 29.
Boarder testing of papayas by the FDA showed three additional positive samples linked to sick individuals. The papayas were from Caraveo Produce in Tecomán, Mexico, which tested positive for Salmonella Infantis and Newport. The Salmonella strains from this shipment have at least one PFGE (Pulsed-field gel electrophoresis) match to a sick person.  WGS (Whole Genome Sequencing) showed genetic relationship between the isolates from the papayas to ill individuals. The relationship between the papaya strains and the individuals can also indicate that previous shipments from Caraveo Produce were likely the cause of previous illnesses. Caraveo Produce identified the Rancho El Ganadero farm in Colima, Mexico as the supplier.
Currently the outbreak is over, and as a result, the final reports were published by the FDA and the CDC. Every few years there is a major outbreak related to imported produce. According to the CDC, in 2015 a major outbreak of Salmonella Poona in cucumbers imported from Mexico caused 907 infections in 40 states with 204 hospitalizations and six deaths. 
According to the CDC In 2011, there was another outbreak due to imported papayas from Mexico. It is important to note that since the last major outbreak, papayas from Mexico have been screened at the border by a third party laboratory. Only papayas that tested negative for Salmonella were allowed to enter the USA. Farms that have five consecutive shipments without Salmonella could be added to a “green” list. Farms with positive Salmonella, testing has been required to demonstrate that they have taken corrective action to prevent future contamination.
The new inspection regime worked for several years without any major infection due to Salmonella. However, the major outbreak this year may require some further thought about the current regulations.
With the implementation of the new FSMA produce rules it is hoped that both the domestic and imported produce will not cause such massive outbreaks.