Listeriosis is a case of food poisoning due to eating food that has been contaminated with the bacterium Listeria monocytogenes. It can affect anyone but mostly occurs in newborns, those pregnant, the elderly and those with compromised immune systems.

L. monocytogenes can be found in the soil and water, contaminating vegetables through the soil or manure used as fertilizer and meats through host animals. Processed food items can also be contaminated due to improper handling and storage, as well as unpasteurized milk or food made from raw milk.

When listeriosis strikes, it can manifest as symptoms like muscle aches and fever, sometimes accompanied by diarrhea or nausea. If the infection reaches the nervous system, stiff necks, headaches, confusion, convulsions and loss of balance may also be experienced. However, it is possible for pregnant women to see no more than mild flu-like symptoms even in their delicate condition. 

The most effective way to determine the presence of a Listeria infection is through a blood test. Depending on what the doctor deems necessary, spinal fluid or urine samples may also be taken to facilitate diagnosis.
Most people infected with Listeria will clear the infection spontaneously in around seven days. Those at higher risk though, like pregnant women, will typically need immediate antibiotic treatment to prevent the infection from progressing into something worse.

Generally, how long an antibiotic treatment lasts will depend on how severe a Listeria infection is. For instance, meningitis will require treatment for three weeks while brain abscesses will need a six-week round of antibiotics. The first choice for antibiotics is usually IV ampicillin but trimethoprim-sulfamethoxazole has also been proven to be effective. For best results, however, treatment will have to be tailored to the specific needs of a patient. In the case of pregnant women, it is also highly recommended that a pediatric specialist and her obstetrician be involved in the treatment for better infection management.

Prognosis for most cases of Listeria is excellent. Success rates do rapidly decline, however, as more risk factors are involved and when diagnosis and treatment are delayed.

Recently, Jeni's Splendid Ice Creams and Blue Bell Creameries recalled their products because of a listeria contamination. The U.S. Food and Drug Administration is looking into implementing a few things to prevent future outbreaks as much as possible. One of the recommended actions is to have food manufacturers prepare a written-down plan for safety. The FDA will come up with a final rule by Aug. 30.

Photo: Czarina Alegre | Flickr

ⓒ 2021 All rights reserved. Do not reproduce without permission.