Listeriosis (synonyms:Listeria monocytogenes; neonatal listeriosis; acute septic listeriosis; chronic septic listeriosis; glandular listeriosis; cutaneous listeriosis; central nervous listeriosis; ICD-10 A32.9: Listeriosis, unspecified) is an infectious disease that occurs sporadically in humans and is caused by bacteria of the genus Listeria. These are Gram-positive, non-spore-forming rod-shaped bacteria. The species Listeria monocytogenes is among the most important pathogens of this genus. Occurrence: Listeria are found primarily in domestic and wild animals. They are also widespread in the agricultural sector. In particular, they can be detected in soil, plants and wastewater. Frequently, the bacteria are found in animal feed. The bacteria can be detected in the stool of infected individuals for months. Transmission of the pathogen (route of infection) can be fecal-oral (infections in which pathogens excreted in feces (fecal) are ingested by mouth (oral)) or through consumption of contaminated food (predominantly animal (raw) foods, but also plant foods such as pre-cut salads). The incubation period (time from infection to onset of disease) in the context of foodborne infection is between 3 and 70 days (usually 3 weeks). Listeriosis can be divided into local (confined to limited areas of the body) and systemic listeriosis. However, local listeriosis plays only a minor role because infections are highly infrequent. Systemic listeriosis typically occurs in patients with a weakened immune system. Pregnant women and elderly patients in particular, but also newborns, are at risk of contracting listeriosis. The pathogen entry site is usually the intestine, because the pathogens are generally ingested via contaminated food. Special features in gravidity (pregnancy)
Pregnancy Listeriosis
- Transplacental listeria infection – if infection occurs after the 3rd month of pregnancy, there is a possibility that listeriosis will infect the fetus (unborn baby) via the placenta. This is possible only after the 3rd month of pregnancy, because at this time the blood circulation through the placenta (placenta) has formed. In the fetus, foci of infection form in the liver, spleen, kidneys, lungs, and brain, characterizing the clinical picture of granulomatosis infantiseptica. The lethality (mortality from the disease) of the fetus is almost 100%.
- Perinatal Listeria infection – when the birth canal is colonized with Listeria, the newborn can become infected during birth.
- Postnatal listeria infection – in this form of the disease, the pathogens originate from the vicinity of the child. In this case, listeriosis often leads to meningitis (meningitis).
Symptoms – Complaints
The symptoms of the most common form of listeriosis, pregnancy listeriosis, are often nonspecific and flu-like, so that as a tentative diagnosis in the pregnant woman is often expressed a flu-like infection or a similar infection picture. Furthermore, it is often seen that symptoms such as fever or aching limbs resolve after a few days, even without therapeutic measures.
Laboratory diagnostics
Pathogen detection is standardly demonstrated by a positive blood culture. Depending on the localization and spread, different examination materials can be used. The following examination materials are suitable for bacterial detection:
- Blood
- CSF (cerebrospinal fluid).
- Amniotic fluid
- Placenta
- Meconium (puerperium – first stool of a newborn).
- Menstrual blood
- Pus
- Biopsies (tissue samples)
Listeria are very resistant bacteria that can survive at 4 °C and also under anaerobic conditions (without oxygen). Thus, the cultivation of Listeria is relatively simple. In order to be able to precisely differentiate whether the bacteria present are Listeria, the property that Listeria can also multiply at 4 °C can be exploited for differentiation. Special selective media are also used to detect the bacteria.Unlike other viral or bacterial pathogens, which can be detected during pregnancy by means of serology (immunological detection method), this is not considered useful in the case of listeriosis. Caution. Since listeria is common in the environment almost everywhere, it is necessary for pregnant women to pay special attention to their diet. The main risk factors for infection are contaminated foods such as raw meat (raw sausage or minced meat), raw milk (unpasteurized milk), soft cheese (made from unpasteurized milk) and also contaminated plant foods. Thus, it is recommended not to store uncooked dairy products or lettuce in the refrigerator for long periods of time, as listeria can multiply well here as well.
Benefit
Early diagnosis is critical for rapid detection and prompt treatment of listeriosis. Treatment is with aminopenicillins (subgroup of pencillins – antibiotic). If necessary, the therapy must be supplemented with aminoglycosides (antibiotic). With the help of this therapy even severe cases of disease can be treated. The duration of treatment depends on the extent of listeriosis. Early treatment with antibiotics is critical for the health of both the pregnant woman and the fetus.
