Listeria (Listeriosis)

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

Persons infected with the outbreak-associated strains of Listeria monocytogenes, by date of illness onset*

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

Onset date not currently available for all persons with reported illness

*n=108 for whom information on illness onset was reported to CDC by 9am EDT on October 6, 2011

Among persons for whom information is available, illnesses began on or after July 31, 2011. Ages range from 22 to 96 years, with a median age of 77 years. Most ill persons are over 60 years old. Fifty-five percent of ill persons are female. Among the 107 ill persons with available information on whether they were hospitalized, 105 (98%) were hospitalized. Three of the ill persons were pregnant women, and one miscarriage has been reported. The outcome of the other two pregnancies is being monitored.

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 11, 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.