Listeria (Listeriosis)

Multistate Outbreak of Listeriosis Linked to Whole Cantaloupes from Jensen Farms, Colorado

Persons infected with the outbreak strain of Listeria monocytogenes, by date of illness onset*

Chart showing bar graph indicating numbers of people infected with the outbreak strains of Listeria monocytogenes, by date of illness onset

Onset data not currently available for all persons with reported illness.

*n=71 for whom information on illness onset was reported to CDC as of 11am EDT on September 26, 2011

Among persons for whom information is available, illnesses began on or after July 31, 2011. Ages range from 35 to 96 years, with a median age of 78 years old. Most ill persons are over 60 years old or have health conditions that weaken the immune system. Fifty-eight percent of ill persons are female. Among the 67 ill persons with available information on whether they were hospitalized, 66 (99%) were hospitalized.

The outbreak can be visually described with a chart showing the number of persons who became ill each day. This chart is called an epidemic curve or epi curve. Illnesses that occurred after September 1, 2011, might not be reported yet due to the time it takes between when a person becomes ill and when the illness is reported. Please see the description of the steps in a foodborne outbreak investigation for more details.