Ongoing collaborative investigations by local, state, and federal public health and regulatory agencies indicate that the source of the outbreak is whole cantaloupe grown at Jensen Farms’ production fields in Granada, Colorado. Among the 84 ill persons with available information on what they ate, 78 (93%) reported consuming cantaloupes in the month before illness onset. Several ill persons remembered the type of cantaloupe they had eaten and said they were Rocky Ford cantaloupes, which are grown in the Rocky Ford region of southeastern Colorado. Source tracing of the cantaloupes that ill persons ate indicated that they came from Jensen Farms, and were marketed as being from the Rocky Ford region. These cantaloupes were shipped from July 29 through September 10 to at least 24 states , with possible further distribution.
Laboratory testing by the Colorado Department of Public Health and Environment identified Listeria monocytogenes bacteria on cantaloupes collected from grocery stores and from ill persons’ homes. Product traceback information from Colorado state officials indicated that these cantaloupes also came from Jensen Farms. Laboratory testing by FDA has identified L. monocytogenes outbreak strains in samples from equipment and cantaloupe at the Jensen Farms’ packing facility in Granada, Colorado. FDA is working closely with CDC, the firms involved, and public health authorities in states where illnesses occurred to determine the exact cause of contamination. Cantaloupes from other farms have not been linked to this outbreak.
Although Jensen Farms issued a voluntary recall of Rocky Ford-brand cantaloupes on September 14 and the recalled cantaloupe should be off store shelves, more ill persons may be reported because of the time lag between diagnosis and laboratory confirmation and also because up to 2 months can elapse between eating contaminated food and developing listeriosis.