Listeriosis: Causes

Pathogenesis (development of disease)

Listeriosis is an infectious disease that occurs sporadically in humans and is caused by Listeria monocytogenes. This species, which belongs to the Listeria group, are gram-positive rod-shaped bacteria. The modes of transmission are diverse:

  • Contamination of food – contamination with infectious excreta.
  • Contact infection
  • Pregnancy or neonatal infections – diaplacental (“transmissible through the placenta“); peripartum (during birth); postnatal (after birth) contact infection.

After ingestion of Listeria, usually gastrointestinal (gastrointestinal tract), they bind to epithelial cells in the small intestine and induce their internalization (internalization). Intracellularly (inside the cells) they are protected against humoral antibodies (immune response takes place in the liquid medium of the body, i.e. in the blood) and multiply there. Elimination (removal) is only possible by T-lymphocytes (special defense cells). This can cause disease in immunosuppressed individuals.

Etiology (causes)

Biographic causes

  • Immunocompromised

Behavioral causes

  • Nutrition
    • Contaminated foods such as raw meat (raw sausage or minced meat); smoked fish; raw milk (unpasteurized milk); soft cheeses made from unpasteurized milk; not uncommonly via contaminated plant foods
  • Contact infections
    • Infection by healthy excretors by the fecal-oral route.
    • Direct contact with infected animals
    • Animal excretions
    • Contaminated water
    • Occurrence in soils

Disease-related causes

Medication