Listeria is in the environment and primarily spreads through the oral route after ingestion of contaminated food. Thereafter the organism penetrates the intestinal tract causing the infections and the diagnosis of listeriosis needs isolation of the organism from the blood or the cerebrospinal fluid.
Listeriosis can be mild in some people with a high temperature, vomiting and diarrhoea and these symptoms pass off within three days with any treatment needed.
In rare cases, the infection could be a bit severe and may spread to other areas of the body resulting in serious complications like meningitis. Some of the common signs of severe listeriosis may include a stiff neck, severe headache and tremors.
Listeria Bacteria – Chilled Food/Ready to Eat
Listeria bacteria are normally found in chilled `ready to eat’, foods which may include pre-packed sandwiches, butter, soft blue cheese, cooked sliced meats, smoked salmon, soft cheese like Brie or Camembert to name a few.
Older adults, with weak immune systems, pregnant women and new-borns are at a greater risk of being affected and it is also very rare that persons without these risk factors can be affected.
The person affected experiences fever and muscle aches and often followed by diarrhoea or some other gastro intestinal symptoms. Mostly all those diagnosed with listeriosis have invasive infection i.e. the bacteria tends to spread from their intestines to their blood stream or other areas of the body and the person gets affected after two months on eating the contaminated food.
Symptoms – Fever/Muscle Ache/Headache/Stiff Neck
The symptoms of the affected person may vary and high riskperson besides pregnant women may suffer from fever, muscle aches, stiff neck, headache, loss of balance confusion and convulsions.
Pregnant women may experience mild flu though the infection during pregnancy may tend to lead to miscarriage, stillbirth, premature delivery or even life threatening infection for the new born.
Previously healthy people who have been exposed to a large dose of Listeria may tend to develop a non-invasive illness which means that the bacteria have not spread in their blood stream or other body areas and the symptoms may include fever and diarrhoea
Maintain Good Food Hygiene
If the person has consumed contaminated food with Listeria but does not have any symptoms, then probably no test or treatment is needed according to expert and even for people at high risk for listeriosis.
The best way of reducing the chances of listeiosis is to make sure that one maintains good food hygiene like not consuming food which is past its expiry dare, by following storage instruction on the food labels, making sure that the temperature of the refrigerator is between 0 degree C and 5 degree C and ensuring that the food is cooked well.
Prevention is better than cure and the main means of prevention can be done by cultivating safe handling, cooking and consumption of food which may include washing raw vegetables well and cooking raw food thoroughly and reheating leftover or ready to eat food till it is steaming hot.