Listeria monocytogenes infection in neonates
- Listeria often presents as a non specific flu like illness.
- Listeria in neonates is life threatening
- Listeria is transmitted to humans via contaminated food.
- Listeria infection is classified as a notifiable disease.
Listeria monocytogenes infection is transmitted to humans via food, especially unpasteurized dairy products contaminated by infected farm animals, soft cheeses, prepared deli meats and refrigerated meat spreads.
Listeria infection is life threatening for neonates and rapid diagnosis and treatment is important.
- In Australia in 2003 there were 4.6 cases per 100,000 births
- The mortality of neonatal listeriosis is about 5-15 per cent.
- Causes a non-specific influenza or gastroenteritic illness in pregnant women during which the organism may infect the fetus by spreading across the placenta or through amniotic fluid.
- First and second trimester infection may cause miscarriage or fetal death.
- Late pregnancy infection may precipitate preterm labour with fetal distress and meconium staining of the liquor.
- Since meconium staining of the liquor is rare below 34 weeks its presence should raise suspicion of listeriosis.
- Characteristically, small (2-3mm) pinkish-grey cutaneous granulomas are present and, at autopsy, similar small granulomatous lesions are widespread in the liver, lungs, CNS and many other tissues and organs.
Early onset infection
- 60% of infants infected intrapartum are preterm and become ill within 24 hours of birth.
- Most have disseminated infection with
- Both blood and stool should be cultured.
- Most cases are sporadic, but epidemics are described.
Late onset infection
Usually presents as meningitis, probably due to nosocomial infection.
Median age of onset is about 14 days.
Febrile pregnant women:
- Culture of blood, cervical & amniotic fluid
- Culture of blood, CSF, gastric aspirate, meconium & infected tissues
Gram stain can be variable and the organism slow growing.
- Penicillin or ampicillin and gentamicin.
- Recommended duration of treatment 2-3 weeks
- Listeria is resistant to all third generation cephalosporins.
- Educate pregnant women to avoid food associated with Listeria
- Investigate pregnant women with flu like symptoms & consider early treatment
- Investigate babies at risk of infection
- Listeriosis (Group B) is a notifiable disease & must be notified in writing within 5 days of diagnosis or online. See Notifying infectious diseases in Victoria.
- Feigh, R. D., and Cherry, J. D. Textbook of pediatric Infectious Diseases (3rd Ed.). Philadelphia: Saunders, 1992.
- Stoll, B. J.Weisman, L.E. Infections in perinatology. Clin. Perinatol. 24:1, 1997.
- Do we really need to worry about Listeria in newborn Infants? The Pediatric Infectious Disease Journal Volume 32, Number 4, April 2013