Definition
Definition
Listeriosis is an infection caused by the bacterium Listeria monocytogenes, which is found in almost every part of the body: animal food, animal and human feces, plants, and soil.
In men, the disease most often develops during pregnancy or during a situation immunosuppression (when the individual does not have all the capacities to defend himself against microbial attacks). A large proportion of listeriosis human is secondary to foodborne transmission of L. monocytogenes.
Generalities
Listeriosis has an incubation period between consumption of contaminated food and illness of 2 to 6 weeks.
Symptoms
Symptoms
Symptoms of listeriosis are:
The long incubation period (the period between contamination and the appearance of the first symptoms of the disease) of listeriosis does not allow for the absolute identification of single and specific sources of food responsible for epidemics.
During pregnancy, listeriosis can occur at any time during gestation. However, most infections are recognized during the third trimester. About half of pregnant women with perinatal listeriosis experience a mild infection characterized by:
- Fever.
- Myalgia (muscle pain).
- A feeling of unease.
- Back pain.
- Diarrhea (sometimes).
- Abdominal pain.
- Nausea and/or vomiting while the bacteria are present in the blood (bacteremia).
The passage of the bacteria through the placenta causes:
- An intrauterine infection that can lead to chorioamnionitis (inflammation of the chorion and amnion).
- Premature onset of labor.
- Death of the fetus in utero.
- Early infection (age less than 7 days) in the newborn.
When antibiotic treatment occurs while listeriosis is recognized during pregnancy, the clinical course is favorable. The diagnosis is made using blood cultures (blood cultures obtained in the laboratory and allowing isolation of the bacteria in question), the isolation of the germ from a rectal or vaginal sample is not contributory. Outside of pregnancy, listeriosis usually occurs in immunocompromised individuals, or in elderly subjects. Predisposing circumstances are prolonged corticosteroid therapy, diabetes mellitus, the existence of a malignant tumor or a hematopathy (blood disease), AIDS, liver diseases, and kidney diseases. The most frequently encountered signs of listeriosis in adults are bacteremia and central nervous system (CNS) involvement. Patients are usually febrile, and their general condition is frequently altered. They sometimes present:
- Myalgia.
- Nausea.
- Vomitings.
- Diarrhea.
L. monocytogenes meningitis is clinically indistinguishable from other types of bacterial meningitis and symptoms include:
- Fever.
- Headaches.
- An alteration of consciousness.
- Ataxia (incoordination of movements with preservation of muscle strength, due to damage to the central nervous system).
- Mental disorders.
- A coma.
- Left heart endocarditis with embolisms (blockage of a vessel by a blood clot) in patients with a prosthetic valve or whose valves have been previously damaged.
Pathophysiology
L. monocytogenes is a pathogenic germ present in the normal gastrointestinal flora of healthy individuals. A lack of gastric acidity or another gastrointestinal problem can increase the risk of disease following invasion of the germ into the digestive tract.
Local immunosuppression of the maternal placenta may facilitate uterine infection following the transient presence of the bacteria in the mother's blood.
Epidemiology
Perinatal listeriosis complicates 16 out of 100 births. Infections cause stillbirths.
Medical exam
Labo
Hyperproteinachia (elevated protein levels) is found in the cerebrospinal fluid (CSF). Diagnosis is made by the presence of L. monocytogenes during culture.
Cause
Cause
Foods implicated in listeriosis outbreaks include:
- Cole slaw (raw cabbage salad with mayonnaise).
- The pies.
- Pig's tongue.
- Undercooked chicken.
- Soft cheeses.
- The uncooked hot dog.
- Food detailed at the counter at grocers.
- Certain type of milk (pasteurized or not).
Treatment
Treatment
The treatment of choice for listeriosis includes:
- Intravenous ampicillin or penicillin, often combined with an aminoglycoside.
- The trimethoprim-sulfamethoxazole combination has been used successfully in patients allergic to penicillin, but clinical experience with this therapeutic class is limited.
- L. monocytogenes is sensitive in vitro to penicillin G, ampicillin, erythromycin, trimethoprim-sulfamethoxazole, chloramphenicol, rifampicin, tetracyclines, and aminoglycosides. Cephalosporins should not be used.
- Treatment during pregnancy can prevent neonatal infection.
- Antibiotic therapy in newborns can limit the after-effects.
Evolution
Evolution
Immunocompromised patients have a poorer prognosis than other adults with listeriosis.
Differential diagnosis
Listeriosis should not be confused with:
- Group A streptococcal infections.
- Toxoplasmosis.
Prevention
Prevention of listeriosis involves a healthy lifestyle:
- Se laver hands.
- Clean kitchen tools used for cutting after handling raw food.
- Maintain your refrigerator with bleach (a solution of a salt derived from chlorine, used as an antiseptic) once a month if possible.
- Cook all raw animal foods such as pork, beef, and poultry thoroughly.
- Wash raw vegetables thoroughly before consumption.
- Avoid soft cheeses and hot dogs.
- Do not store uncooked meat with vegetables, ready-to-eat foods, or cooked foods.