How does infection occur?
Listeria is widespread in soil, water and farm animals. It gets into food at the stage of processing and storage. The main danger is that the bacterium retains the ability to grow at the temperature of a household refrigerator, and therefore grows in products with a long shelf life that are eaten without heat treatment. Infection does not occur from person to person, with the exception of transmission from mother to fetus through the placenta or to the child during childbirth.
- Soft and pickled cheeses made from unpasteurized milk
- Unpasteurized milk and cottage cheese from the market
- Ready-made salads, pates, cold cuts
- Cold smoked fish and seafood
- Poorly washed vegetables and herbs
- Vertical transmission from mother to fetus
Symptoms
The incubation period ranges from a few days to two months, making it difficult to link the disease to a specific product. The gastroenteric form develops quickly and resembles ordinary food poisoning. Invasive forms begin later and are difficult. In pregnant women, the symptoms are often blurred: fever, aches, weakness, sometimes lower back pain, while the fetus suffers more than the mother.
- Fever, chills, muscle aches
- Nausea, vomiting, watery diarrhea
- Headache, photophobia, stiff neck due to meningitis
- Seizures and balance disorders due to brainstem damage
- In pregnant women - a flu-like condition without an obvious focus
- The newborn has respiratory problems, rash, lethargy, jaundice
What are the dangers during pregnancy?
Pregnant women become infected with listeria more often than other adults due to a physiological change in the immune response. The woman herself usually experiences the infection as a mild illness, but the bacterium penetrates the placenta. The consequences depend on the period: in the early stages, termination of pregnancy is possible, in the second and third trimester - premature birth, intrauterine infection, damage to the lungs and brain of the child. Antibiotics started in a timely manner significantly reduce the risk to the fetus, so any unexplained fever during pregnancy should be shown to a doctor and not waited out at home.
- Miscarriage and missed miscarriage in the early stages
- Premature birth
- Intrauterine infection, pneumonia and meningitis in a newborn
- Early neonatal sepsis
- Late form in a child in the second to fourth week of life
Diagnostics
The diagnosis is made by isolating Listeria from normally sterile environments: blood, cerebrospinal fluid, placenta, amniotic fluid. Therefore, the key test is a bacteriological culture taken before starting antibiotics. A complete blood count and C-reactive protein show the severity of inflammation, but do not indicate the pathogen. Stool analysis is not used to diagnose invasive listeriosis because the bacterium can also be found in healthy carriers. Serological tests are uninformative and have no independent significance.
- Blood culture for sterility
- Culture and analysis of cerebrospinal fluid for suspected meningitis
- Culture of placenta, amniotic fluid, birth canal secretions
- Complete blood count and C-reactive protein
- Culture of material from a newborn
- MRI of the brain for focal neurological symptoms
Treatment and prevention
Listeriosis is treated with antibiotics, and only a doctor selects them: the bacterium is resistant to some drugs that are usually prescribed for other infections, so self-medication is dangerous. For gastroenteritis in a healthy adult, drinking and observing is often sufficient. Invasive forms, listeriosis in pregnant women and newborns are treated in a hospital intravenously and for a long time. Prevention comes down to food hygiene, and it is stricter for pregnant women than for others.
- Antibiotic therapy as prescribed by a doctor, in severe forms - intravenously
- Hospitalization of pregnant women, newborns and patients with meningitis
- Avoiding unpasteurized milk and soft cheeses during pregnancy
- Reheating cooked meats before eating
- Separate storage of raw and prepared foods, regular cleaning of the refrigerator
- Thorough washing of vegetables, herbs and hands after handling raw meat
