Today the Food and Drug Administration (FDA) announced that it was halting the importation of all Mexican-sourced papayas into the US.  FDA has been collecting and analyzing samples of raw, fresh whole papaya imported from Mexico. From May 12, 2011, to August 18, 2011, FDA analysis found Salmonella in 33 samples out of a total of 211, or a 15.6% positive rate. The positive samples were from 28 different firms and include nearly all the major papaya producing regions in Mexico.

Mexico produces 11% of the world’s production of papayas. U.S. import data from January 1, 2011 shows that approximately 65% of all papayas imported into the U.S. are from Mexico (primarily from the Mexican states of Jalisco, Colima, Chiapas, and Veracruz), which makes Mexico the largest exporter of fresh papayas into the U.S. Evidence shows there is widespread contamination of Mexican papaya with Salmonella, a human pathogen. Based on this evidence, FDA has determined that papaya imported from Mexico appears to be adulterated within the meaning of section 402(a)(1) of the Federal Food, Drug, and Cosmetic Act because the papayas appear to contain Salmonella, an added poisonous or deleterious substance that may render food injurious to health.

In addition, a multi-state outbreak of human infections of salmonellosis occurred in 2011. More than 100 people were infected with the outbreak organism in multiple states. The pathogen, identified as Salmonella Agona, is attributable to a specific, uncommon serotype of Salmonella with an indistinguishable pulsed-field gel electrophoresis (PFGE) pattern by two enzymes.

In the course of the investigation of this outbreak, CDC identified papaya as a likely vehicle. At the same time, State public health agencies conducted interviews of cases to identify the sources of papaya purchased by cases. Using the information provided by the cases, tracebacks were conducted in multiple states. FDA also collected samples of papaya to test for the outbreak strain. Based on information from the outbreak investigation, the outbreak has been associated with papaya from at least one grower and its shipper in Mexico.

Salmonella lives in the intestinal tracts of humans and other animals. The organism may be transmitted to humans by eating foods contaminated with Salmonella from sources of microbial exposure from animals such as birds, mammals and reptiles, or humans. Based on the evidence described above, FDA believes that it is extremely unlikely that the Salmonella Agona outbreak, or the elevated rate of positive samples from FDA’s recent testing of papayas from Mexico, is due to random contamination events in nature.