Epi Curves

Multistate Outbreak of Listeriosis Linked to Whole Cantaloupes from Jensen Farms, Colorado (FINAL UPDATE)

This investigation is closed.Listeria monocytogenes infection (listeriosis) is an important cause of illness in the United States. More information about listeriosis, and steps people can take to reduce their risk of infection, can be found on the CDC Listeria website.

Final Epi Curve - August 27, 2012 (FINAL Update Addendum)

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.

Persons infected with an outbreak-associated subtype of Listeria monocytogenes, by date of illness onset (Figure A) and date of clinical specimen collection (Figure B), 2011  (147 cases reported to CDC as outbreak-associated)*

Chart showing bar graph indicating numbers of persons infected with the outbreak-associated strains of Listeria monocytogenes, by 8-27-2012 of illness onset

* Onset date not currently available for all persons with reported illness. Excludes a newborn diagnosed with listeriosis with a specimen date in November whose mother was reported as a case earlier in the outbreak.

Among persons for whom information was available, reported illness onset ranged from July 31, 2011 through October 27, 2011. Ages ranged from <1 to 96 years, with a median age of 78 years. Most ill persons were over 60 years old. Fifty-eight percent of ill persons were female. Among the 145 ill persons with available information on whether they were hospitalized, 143 (99%) were hospitalized.

Thirty-three outbreak-associated deaths were reported: Colorado (9), Indiana (1), Kansas (3), Louisiana (2), Maryland (1), Missouri (3), Montana (1), Nebraska (1), New Mexico (5), New York (2), Oklahoma (1), Texas (2), and Wyoming (2). Among persons who died, ages ranged from 48 to 96 years, with a median age of 81 years. In addition, one woman pregnant at the time of illness had a miscarriage.

Seven of the illnesses were related to a pregnancy; three were diagnosed in newborns and four were diagnosed in pregnant women. One miscarriage was reported.

Previous Epi Curves