Lessons learned from cantaloupe-listeria outbreak

September 5, 2013 by Steven Reinberg, Healthday Reporter

Lessons learned from cantaloupe-listeria outbreak
CDC report confirms potential for fresh produce to cause severe foodborne illness.
(HealthDay)—Of all the dangerous bacteria lurking in foods, perhaps the most deadly is listeria, and the lesson from a 2011 outbreak is to always handle food safely, U.S. health officials say.

In the summer and fall of 2011, cantaloupes contaminated with sickened 147 people in 28 states, killing 33 of them. That listeria outbreak—the deadliest in a decade—was unusual because listeria is rarely associated with fresh produce, according to a new report from the U.S. Centers for Disease Control and Prevention (CDC).

Although rare, listeria is an important public-health issue because of its severity, said report co-author Benjamin Silk, a CDC in the division of foodborne, waterborne and environmental diseases. "Nearly all people who have diagnosed are hospitalized, and about one in five die," Silk said.

The new report, published Sept. 5 in the New England Journal of Medicine, highlights lessons learned from an investigation into the 2011 outbreak.

The authors found that for the 145 people for whom complete records were available, all but two were hospitalized and nearly one-quarter died.

Most of those sickened were in their 60s or older and suffered from other illnesses. But there also were seven pregnancy-associated infections among four women and three infants. One of the four women miscarried because of the infection.

Overall, this is typical of the general consequences of a listeria outbreak, one expert said.

"Listeria is only a problem for immuno-compromised folks and pregnant women, but in those cases people can and do get quite ill and almost all are hospitalized," said Dr. Marc Siegel, an associate professor of medicine at the NYU Langone Medical Center in New York City.

"In this case, pregnant women were a small percentage, though they are usually more," he said. "Outbreaks are limited as healthy people don't generally get ill."

The contaminated cantaloupes were traced to a Colorado grower, and while the exact cause of the contamination isn't known, unsanitary conditions were likely the culprit, according to the report.

"The problem is that listeria bacteria grows on produce—in this case cantaloupes—and occurs especially when proper precautions aren't taken at the farm or processing facility," Siegel said.

One possible contributor to the outbreak is inadequate facility and equipment design, which hampered thorough cleaning of surfaces the melons could touch, according to the report. Another possible route to contamination is a truck kept next to the processing line that went to and from a cattle operation.

In addition, the Colorado farm did not cool its before placing them in cold storage, which may have caused condensation that promoted the growth of listeria.

"This outbreak confirms the viability of raw produce, including cantaloupe, as a vehicle for listeriosis and highlights the importance of preventing produce contamination within farm and processing environments," the report noted.

Listeria is associated with about 1,600 infections in the United States annually, Silk said. A partnership between the CDC and state health departments, known as the Listeria Initiative, enabled the agency quickly to identify the source of the 2011 outbreak, he said.

The CDC continues to monitor and follow up on all listeria cases, Silk said. In addition, the FDA has stepped up inspections of cantaloupe farms and has issued guidelines to cantaloupe growers.

The best way to avoid listeria is to follow common-sense food-safety procedures, Silk said.

To help prevent infection, the CDC recommends you do the following:

  • Rinse fruits and vegetables thoroughly under running water before eating, cutting or cooking them.
  • Scrub farm produce, such as melons and cucumbers, with a clean produce brush.
  • Dry produce with a clean cloth or paper towel.
  • Separate uncooked meats and poultry from vegetables, cooked foods and ready-to-eat foods.
  • Wash hands, knives, countertops and cutting boards after handling and preparing uncooked foods.
  • Because listeria can grow in foods in the refrigerator, keep the temperature of your refrigerator at 40 degrees or lower and the freezer at 0 degrees or lower.
  • Clean up all spills in the refrigerator, especially juices from hot dogs, lunch meat, raw meat and raw poultry.
  • Clean the inside walls and shelves of the refrigerator with hot water and liquid soap, and then rinse.
  • Thoroughly cook beef, pork or poultry.

Explore further: Listeria food poisoning hits elderly, moms-to-be hardest: CDC

More information: For more information on listeria, visit the U.S. Centers for Disease Control and Prevention.

Related Stories

Listeria food poisoning hits elderly, moms-to-be hardest: CDC

June 4, 2013
(HealthDay)—Soft cheese and raw produce have caused many recent listeria outbreaks in the United States, and at least 90 percent of cases typically occur among seniors, pregnant women, newborns and people with weakened ...

21 deaths now linked to listeria in cantaloupe

October 7, 2011
(AP) -- Federal health authorities say a nationwide outbreak of listeria in cantaloupe is now responsible for 21 deaths and the number may continue to grow.

CDC reports 4 dead in cantaloupe listeria outbreak

September 20, 2011
(AP) -- Four people have died in an outbreak of listeria traced to Colorado cantaloupes, the Centers for Disease Control and Prevention said Monday.

Infected cantaloupes have killed 18 in US

October 4, 2011
Eighteen people have died and 100 people have fallen ill since late July in the United States from eating cantaloupes infected with listeria, health authorities said Tuesday.

Final toll from melon listeria outbreak: 30 dead

December 9, 2011
(AP) -- U.S. health authorities say the final death toll from an outbreak of listeria in cantaloupe is 30.

Killer US cantaloupes expected to infect more people

September 28, 2011
Cantaloupes infected with listeria have sparked the deadliest US foodborne disease outbreak in over a decade and are likely to claim more victims in the weeks ahead, officials said Wednesday.

Recommended for you

Taking the virus out of a mosquito's bite

December 12, 2018
They approach with the telltale sign—a high-pitched whine. It's a warning that you are a mosquito's next meal. But that mosquito might carry a virus, and now the virus is in you. Now, with the help of state-of-the-art technology, ...

Study identifies a key cellular mechanism that triggers pneumonia in humans

December 11, 2018
The relationship between influenza and pneumonia has long been observed by health workers. Its genetic and cellular mechanisms have now been investigated in depth by scientists in a study involving volunteers and conducted ...

Human antibody discovery could save lives from fungal killer

December 11, 2018
A new way to diagnose, treat and protect against stealth fungal infections that claim more than 1.5 million lives per year worldwide has been moved a step closer, according to research published in Nature Communications.

Effect of oral alfacalcidol on clinical outcomes in patients without secondary hyperparathyroidism

December 11, 2018
Treatment with active vitamin D did not decrease cardiovascular events in kidney patients undergoing hemodialysis, according to a research group in Japan. They have reported their research results in the December 11 issue ...

Dialysis patients at risk of progressive brain injury

December 10, 2018
Kidney dialysis can cause short-term 'cerebral stunning' and may be associated with progressive brain injury in those who receive the treatment for many years. For many patients with kidney failure awaiting a kidney transplant ...

Silicosis is on the rise, but is there a therapeutic target?

December 6, 2018
Researchers from the CNRS, the University of Orléans, and the company Artimmune, in collaboration with Turkish clinicians from Atatürk University, have identified a key mechanism of lung inflammation induced by silica exposure, ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.