What you need to know about Listeria monocytogenes
September 28th, 2011
12:35 PM ET

What you need to know about Listeria monocytogenes

With an outbreak of sickness linked to  bacteria-tainted cantaloupe now reported in more than a dozen states, here's a quick backgrounder on listeria monocytogenes.

What is it?
Listeria monocytogenes is a “hardy” bacterium that is resistant to extreme hot and cold. This bacterium is pathogenic – meaning that it is infectious to humans, causing the illness listeriosis.

Where does it come from?
Listeria is found in soil, water and the intestines of some animals. Unfortunately, most animals show no symptoms so the bacterium is transferred to raw foods such as unpasteurized dairy products, raw vegetables and raw meats. And unlike similar types of bacteria, listeria can grow in the low temperatures of a refrigerator.

Studies also suggest that up to 10% of humans may be carriers. The FDA says that when listeria gets into a factory environment it can live for several years.

But how did it get inside of cantaloupes?
Cantaloupes and other fruits with porous surfaces can become infected by listeria when soil and/or water seeps through their skin. Any bacterium that remains on the outside can be transferred from the shell to the inside when the fruit is sliced open by a knife or handled.

Who is most at risk?
Listeriosis primarily affects the elderly, pregnant women, newborns, and people with weakened immune systems. In the U.S., an estimated 1,600 people become seriously ill each year; approximately 16% of these illnesses result in death. Cervical infections caused by listeriosis in pregnant women may result in spontaneous abortion during the second or third trimesters or stillbirth.

What are the symptoms of listeriosis?
The early symptoms of listeriosis are similar to those of the flu with nausea, muscle aches and a high fever. Gastrointestinal symptoms such as diarrhea may also appear. The length of time between infection and the appearance of symptoms is unknown.

How can I protect myself?
Recommendations for keeping food safe from listeria are similar to those used to protect against other foodborne illnesses. Remember to cook meat to the USDA’s recommended temperatures and to wash all raw vegetables and fruit. Keep your fridge below 40 degrees Fahrenheit and eat leftovers within three to four days, the CDC says.

I’ve eaten a cantaloupe! What should I do?
Your risk of developing listeriosis is extremely low, even if the cantaloupe you ate was contaminated. If you do not have any symptoms you’re most likely in the clear. However, if you’re in one of the high risk groups and showed symptoms up to two months after eating a possibly contaminated product, contact your doctor.

Has this happened before?
About 800 cases of Listeria infection are diagnosed each year in the United States, along with three or four outbreaks of Listeria-associated foodborne illness. A multi-state outbreak of listeria from contaminated hot dogs and deli meats occurred in 1998, killing 21. Between 1998 and June 2009, 48 deaths from listeria-caused illnesses were reported by the CDC’s Foodborne Outbreak Online Database.

Got a question about the outbreak? Ask it below and we’ll do our best to find an answer.

To learn more visit the FDA's Bad Bug Book or the CDC's section on listeriosis.

soundoff (4,477 Responses)
  1. chinese food delivery near me

    Can I just say what a relief to uncover an individual who truly knows what they're discussing over the internet. You certainly understand how to bring a problem to light and make it important. A lot more people need to check this out and understand this side of your story. I was surprised that you're not more popular because you surely have the gift.


    June 21, 2021 at 04:01 | Report abuse | Reply
  2. Kevinfeems

    chloroquine for sale chloroquine tablet price – chloroquine for sale
    https://doxycyclinetop.com/# generic doxycycline

    June 21, 2021 at 04:35 | Report abuse | Reply
  3. Jerrylen

    amoxicillin online pharmacy buy amoxicillin – amoxicillin buy online canada
    http://amoxicillintop.com/# amoxicillin 500 mg online
    buy neurontin 300 mg gabapentin neurontin 50mg tablets

    June 21, 2021 at 05:40 | Report abuse | Reply
  4. FrancisRorgo

    http://neurontintop.com/# neurontin cost in canada
    chloroquine order aralen online buy chloroquine phosphate canada

    June 21, 2021 at 05:42 | Report abuse | Reply
  5. Kevinfeems

    doxycycline generic buy doxycycline online without prescription – doxycycline 150 mg
    https://amoxicillintop.com/# buy amoxicillin from canada

    June 21, 2021 at 07:07 | Report abuse | Reply
  6. RV Repair Orange County


    June 21, 2021 at 07:40 | Report abuse | Reply
  7. escape rooms near me

    Excellent site you have here.. Itís difficult to find high quality writing like yours these days. I really appreciate individuals like you! Take care!!


    June 21, 2021 at 07:47 | Report abuse | Reply
  8. Jerrylen

    generic neurontin neurontin 1800 mg – neurontin price
    http://chloroquinetop.com/# chloroquine for sale
    doxycycline without a prescription generic doxycycline buy cheap doxycycline

    June 21, 2021 at 08:11 | Report abuse | Reply
  9. FrancisRorgo

    http://amoxicillintop.com/# amoxicillin from canada
    amoxicillin from canada amoxicillin without rx buy amoxicillin 500mg capsules uk

    June 21, 2021 at 08:17 | Report abuse | Reply
  10. Kevinfeems

    amoxicillin tablets in india buy amoxil – where can i buy amoxicillin online
    http://amoxicillintop.com/# amoxicillin capsule 500mg price

    June 21, 2021 at 09:40 | Report abuse | Reply
  11. Jerrylen

    generic gabapentin buy gabapentin – neurontin 200 mg
    http://amoxicillintop.com/# amoxicillin 250 mg
    chloroquine phosphate aralen buy chloroquine phosphate buy chloroquine canada

    June 21, 2021 at 10:45 | Report abuse | Reply
  12. Sprinter Repair Near Me

    Hello there, There's no doubt that your web site could be having internet browser compatibility issues. Whenever I look at your website in Safari, it looks fine however when opening in IE, it has some overlapping issues. I just wanted to provide you with a quick heads up! Other than that, wonderful site!


    June 21, 2021 at 10:56 | Report abuse | Reply
  13. FrancisRorgo

    https://neurontintop.com/# neurontin 4000 mg
    amoxicillin 500 mg tablet price purchase amoxicillin online can we buy amoxcillin 500mg on ebay without prescription

    June 21, 2021 at 10:56 | Report abuse | Reply
  14. Kevinfeems

    buy chloroquine phosphate chloroquine usa – order aralen online
    https://chloroquinetop.com/# can you buy chloroquine over the counter

    June 21, 2021 at 12:13 | Report abuse | Reply
  15. flower shops near me


    June 21, 2021 at 13:13 | Report abuse | Reply
  16. usps near me


    June 21, 2021 at 13:16 | Report abuse | Reply
  17. Jerrylen

    where to buy chloroquine chloroquine india – chloroquine
    https://neurontintop.com/# neurontin capsule 600mg
    aralen for sale buy aralen buy chloroquine phosphate

    June 21, 2021 at 13:20 | Report abuse | Reply
  18. RV Repair Parts Near Me

    Greetings, I think your site may be having browser compatibility issues. When I take a look at your web site in Safari, it looks fine however when opening in IE, it's got some overlapping issues. I merely wanted to provide you with a quick heads up! Other than that, great website!


    June 21, 2021 at 13:52 | Report abuse | Reply
  19. FrancisRorgo

    http://chloroquinetop.com/# aralen medication
    gabapentin 300mg buy gabapentin gabapentin 300mg

    June 21, 2021 at 14:13 | Report abuse | Reply
  20. Kevinfeems

    buy doxycycline generic doxycycline – doxycycline tablets
    https://doxycyclinetop.com/# buy doxycycline online

    June 21, 2021 at 15:20 | Report abuse | Reply
  21. Jerrylen

    how to get amoxicillin amoxil – order amoxicillin online no prescription
    https://chloroquinetop.com/# buy chloroquine
    neurontin 4 mg buy gabapentin neurontin 600 mg tablet

    June 21, 2021 at 15:54 | Report abuse | Reply
  22. RV Repair San Clemente California


    June 21, 2021 at 16:34 | Report abuse | Reply
  23. RV Repair Shop


    June 21, 2021 at 17:12 | Report abuse | Reply
  24. FrancisRorgo

    https://amoxicillintop.com/# buy amoxicillin
    brand name neurontin gabapentin gabapentin medication

    June 21, 2021 at 17:24 | Report abuse | Reply
  25. Jerrylen

    amoxicillin for sale amoxil – amoxicillin 250 mg capsule
    http://neurontintop.com/# neurontin 500 mg
    neurontin 400mg neurontin generic cost of neurontin 600 mg

    June 21, 2021 at 18:26 | Report abuse | Reply
  26. RV Repair Shops Near My Location


    June 21, 2021 at 18:32 | Report abuse | Reply
  27. Kevinfeems

    generic doxycycline buy doxycycline online – doxy 200
    https://doxycyclinetop.com/# doxycycline generic

    June 21, 2021 at 18:45 | Report abuse | Reply
  28. Wheelchair Van Repair


    June 21, 2021 at 18:56 | Report abuse | Reply
  29. Jerrylen

    medicine amoxicillin 500mg amoxicillin 500 mg without a prescription – where can i buy amoxicillin online
    https://amoxicillintop.com/# amoxicillin order online no prescription
    neurontin 800 mg cost buy gabapentin neurontin price comparison

    June 21, 2021 at 20:59 | Report abuse | Reply
  30. Kevinfeems

    neurontin 300 mg cap gabapentin – neurontin 400 mg capsule
    http://neurontintop.com/# neurontin 100 mg cost

    June 21, 2021 at 21:38 | Report abuse | Reply
  31. RV Mobile Repair Near Me


    June 21, 2021 at 22:45 | Report abuse | Reply
  32. mexican restaurant near me

    Greetings! Very useful advice in this particular article! It's the little changes which will make the greatest changes. Thanks for sharing!


    June 21, 2021 at 23:15 | Report abuse | Reply
  33. Jerrylen

    where to buy chloroquine buy aralen – buy chloroquine phosphate canada
    https://doxycyclinetop.com/# where to get doxycycline
    neurontin 400 mg capsule neurontin neurontin 800 mg capsules

    June 21, 2021 at 23:32 | Report abuse | Reply
  34. Kevinfeems

    neurontin 10 mg buy neurontin online – neurontin 4 mg
    http://doxycyclinetop.com/# doxy 200

    June 22, 2021 at 00:06 | Report abuse | Reply
  35. Jerrylen

    amoxicillin 750 mg price amoxicillin 500 mg without a prescription – amoxicillin pills 500 mg
    https://chloroquinetop.com/# where to buy chloroquine
    chloroquine for sale cheap chloroquine aralen

    June 22, 2021 at 02:04 | Report abuse | Reply
  36. Kevinfeems

    buy chloroquine aralen for sale – chloroquine
    https://neurontintop.com/# neurontin pills

    June 22, 2021 at 02:36 | Report abuse | Reply
  37. online financial training

    Having read this I thought it was rather informative. I appreciate you finding the time and energy to put this information together. I once again find myself personally spending a significant amount of time both reading and posting comments. But so what, it was still worthwhile!


    June 22, 2021 at 02:37 | Report abuse | Reply
  38. RV Repair Santa Ana

    Your style is unique compared to other folks I have read stuff from. I appreciate you for posting when you have the opportunity, Guess I will just bookmark this site.


    June 22, 2021 at 02:46 | Report abuse | Reply
  39. Sprinter Ecu Repair

    Oh my goodness! Awesome article dude! Thank you, However I am having problems with your RSS. I donít know the reason why I can't join it. Is there anybody else getting similar RSS issues? Anybody who knows the answer can you kindly respond? Thanx!!


    June 22, 2021 at 03:04 | Report abuse | Reply
  40. Jerrylen

    neurontin 800 mg capsules buy gabapentin – neurontin 100mg price
    http://amoxicillintop.com/# ampicillin amoxicillin
    generic amoxil 500 mg buy amoxil where can you get amoxicillin

    June 22, 2021 at 04:38 | Report abuse | Reply
  41. Nissan Luxury Van Repair Shop Near Me

    You are so cool! I don't think I've truly read a single thing like that before. So nice to discover someone with genuine thoughts on this subject matter. Seriously.. many thanks for starting this up. This website is one thing that is needed on the web, someone with some originality!


    June 22, 2021 at 04:52 | Report abuse | Reply
  42. Sprinter Door Rust Repair


    June 22, 2021 at 05:04 | Report abuse | Reply
  43. Kevinfeems

    buy aralen buy chloroquine phosphate canada – aralen for sale
    http://doxycyclinetop.com/# order doxycycline 100mg without prescription

    June 22, 2021 at 05:05 | Report abuse | Reply
  44. Jerrylen

    doxylin buy doxycycline online without prescription – doxycycline 100mg capsules
    https://neurontintop.com/# neurontin brand name in india
    neurontin 300 mg neurontin generic how much is generic neurontin

    June 22, 2021 at 07:13 | Report abuse | Reply
  45. RV Repair Near Me Now

    This blog was... how do I say it? Relevant!! Finally I've found something that helped me. Many thanks!


    June 22, 2021 at 07:32 | Report abuse | Reply
  46. Kevinfeems

    doxycycline hydrochloride 100mg buy doxycycline online – doxycycline monohydrate
    http://amoxicillintop.com/# amoxicillin generic

    June 22, 2021 at 07:35 | Report abuse | Reply
  47. RV Repair Places Near Me


    June 22, 2021 at 09:36 | Report abuse | Reply
  48. Jerrylen

    doxycycline order online buy doxycycline 100mg – doxycycline generic
    http://doxycyclinetop.com/# odering doxycycline
    buy doxycycline buy doxycycline online without prescription buy cheap doxycycline online

    June 22, 2021 at 09:48 | Report abuse | Reply
  49. Kevinfeems

    generic for doxycycline doxycycline – doxycycline vibramycin
    https://neurontintop.com/# neurontin buy online

    June 22, 2021 at 10:04 | Report abuse | Reply
  50. Jerrylen

    amoxicillin cephalexin purchase amoxicillin online – where to get amoxicillin over the counter
    http://doxycyclinetop.com/# doxycycline 500mg
    amoxicillin 500mg capsule buy online buy amoxicillin amoxicillin 500mg buy online canada

    June 22, 2021 at 12:22 | Report abuse | Reply
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89

Post a comment


CNN welcomes a lively and courteous discussion as long as you follow the Rules of Conduct set forth in our Terms of Service. Comments are not pre-screened before they post. You agree that anything you post may be used, along with your name and profile picture, in accordance with our Privacy Policy and the license you have granted pursuant to our Terms of Service.

About this blog

Get a behind-the-scenes look at the latest stories from CNN Chief Medical Correspondent, Dr. Sanjay Gupta, Senior Medical Correspondent Elizabeth Cohen and the CNN Medical Unit producers. They'll share news and views on health and medical trends - info that will help you take better care of yourself and the people you love.