Human Listeriosis: An Update

Listeriosis in human is clinically characterized as perinatal listeriosis, neonatal listeriosis and adult listeriosis. Listeria spp are an established pathogen in animals, and human infections are usually seen following ingestion of contaminated food (processed food). Human infections of Listeria spp initially present with gastrointestinal symptoms. Meningitis, septicaemia, brain abscess and probably intrauterine and neonatal infections are considered as frequent complications of infection with Listeria spp. Of the six species of Listeria identified thus far, L monocytogenes and L ivanovii are considered as pathogenic strains to humans and animals respectively. Listeria monocytogenes are facultative intracellular bacterial pathogens, which pose a potential public health problem related to consumption of contaminated food that is facilitated by their ability to tolerate high concentrations of salt and able to survive and multiply in refrigeration temperatures. From being a saprophyte, pathogen responsible for abortion in cattle, Listeria spp have evolved in to potential human pathogens with ever increasing reports of human listeriosis.