Listeriosis is a gram-positive bacterial infection that primarily affects neonates, pregnant women, adults over 45 to 50 years of age, and immunocompromised people.
It is mainly a food-borne disease. Prevention consists of hand hygiene, cooking food well, and avoiding unwashed and leftover food.
Outbreaks have been reported worldwide, with the reported source of contamination including cantaloupe melons, frozen vegetables, and chilled pork.
Bacteremia, sepsis, meningitis, encephalitis, brain abscess, endocarditis, and gastroenteritis are the most common clinical manifestations.
Cultures from clinically sterile sites and serologic tests are the keys for laboratory diagnosis.
Ampicillin is the preferred drug for initial treatment for systemic (non-gastroenteritis) manifestations. Gastroenteritis alone is usually self-limited.
Listeriosis is a food-borne infection caused by a motile, nonspore-forming, gram-positive bacillus. Its incidence is relatively low in the general population.
History and exam
Key diagnostic factors
- altered mental status
Other diagnostic factors
- diarrhea and abdominal pain
- generalized malaise
- flu-like symptoms in pregnancy
- poor feeding (neonates)
- cranial nerve deficits
- cerebellar signs
- focal neurologic signs
- intrapartum fever
- bleeding diathesis with hemorrhage
- cardiac murmur
- exposure to contaminated food
- age >45-50 years
- immunocompromised states
- impaired stomach acidification
1st investigations to order
- urine pregnancy test
- blood cultures
- brain MRI
- brain CT
- cerebrospinal fluid (CSF) analysis
Investigations to consider
- prothrombin time (PT) and PTT
- placenta and amniotic fluid culture
- cervical swab culture
- meconium Gram stain and culture
- Listeria serology
- food analysis
- stool culture
- polymerase chain reaction of blood
- other stool analyses
- meningitis/encephalitis panel
systemic infection: not gastroenteritis, not meningitis/meningoencephalitis
- Other bacterial meningitides
- Other brain abscesses
- Viral gastroenteritis
- Listeria (Listeriosis)
- ACOG Committee Opinion No. 614: Management of pregnant women with presumptive exposure to Listeria monocytogenes
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