The CDC has released a final report on the multistate outbreak of Listeriosis linked to whole cantaloupes from Jensen Farms in Colorado.
The outbreak affected people in 28 states and was the most deadly outbreak of a foodborne illness in this country in 100 years. The government has stated that available evidence indicates the outbreak is over. The CDC has more information about listeriosis and how to protect yourself.
A total of 146 people were sickened. Thirty people died. Almost all of the affected persons became so ill they were hospitalized. The timeline of events in this case lists the report of outbreaks, traceback investigations, and the recall. This is the final outbreak toll, by state:
- Alabama: 1 case
- Arkansas: 1 case
- California: 4 cases
- Colorado: 40 cases, 8 deaths
- Idaho: 2 cases
- Illinois: 4 cases
- Indiana: 3 cases, 1 death
- Iowa: 1 case, 1 miscarriage
- Kansas: 11 cases, 3 deaths
- Louisiana: 2 cases, 2 deaths
- Maryland: 1 case, 1 death
- Missouri: 7 cases, 3 deaths
- Montana: 1 case
- Nebraska: 6 cases, 1 death
- Nevada: 1 case
- New Mexico: 15 cases, 5 deaths
- New York: 2 cases, 2 deaths
- North Dakota: 2 cases
- Oklahoma: 12 cases, 1 death
- Oregon: 1 case
- Pennsylvania: 1 case
- South Dakota: 1 case
- Texas: 18 cases, 2 deaths
- Utah: 1 case
- Virginia: 1 case
- West Virginia: 1 case
- Wisconsin: 2 cases
- Wyoming: 4 cases, 1 death
The CDC states that those who died ranged in age from 48 to 96 years. The median age was 82.5. Most (58%) of the infected persons were female. Most people who became ill were over 60 years old. In addition, seven illnesses were related to a pregnancy, and three infants were born with listeriosis. The illnesses occurred from July 31 to October 27, 2011.
Source: Centers for Disease Control
In this case, the CDC worked with the FDA and public officials in several states to identify the source of the outbreak. Listeriosis is caused by eating food contaminated with the Listeria monocytogenes bacterium. DNA analysis isolated from patients was used to identify the particular strain of bacteria. Pulsed-field gel electrophoesis (PFGE) determined the bacteria’s “fingerprint”.
The epidemiological curve (epi curve) is critical for determining when an outbreak begins and ends. During an investigation, there is usually a delay of a few days, up to five weeks, between infection and confirmation of the illness. The epi curve should become a rough bell curve, but only after enough time has passed. Each outbreak has a different epi curve.
The source of the outbreak was whole cantaloupe grown at Jensen Farms in Granada, Colorado. The cantaloupes were shipped from July 29, 2011 through September 10, 2011 to at least 24 states. Of the 140 people who gave an account of what they ate before becoming ill, 94% said they had consumed cantaloupe. Lab tests identified Listeria monocytogenes on cantaloupes at grocery stores and in the patient’s homes. Product traceback information linked the cantaloupes to Jensen Farms, which recalled all of the 1.5 million Rocky-Ford cantaloupes it had shipped for the season.
Listeriosis is a serious disease, caused by eating food contaminated with the Listeria bacterium. The people most seriously affected include persons with chronic illnesses and weakened immune systems, elderly persons, pregnant women, and newborns. Symptoms include muscle aches, fever, GI symptoms such as diarrhea, headache, stiff neck, loss of balance, confusion, and convulsions. Even healthy people can develop invasive listeriosis.
This outbreak stresses the fact that consumers should wash all produce before tasting the food, even fruits and vegetables such as cantaloupe and onions that are peeled before eating. If the surface of produce is contaminated with bacteria, cutting through the peel can spread bacteria to the interior of the product.
It’s possible that cantaloupes under the recall are still in homes. If you have a cantaloupe with a Jensen Farms sticker, dispose of it in a closed plastic bag placed in a sealed trash can. Sterilize your refrigerator, counter tops, cutting boards, and knives. And always wash your hands before and after handling food.
