Invasive listeriosis (bacteremia or meningitis) in pregnancy leads to major fetal consequences, including fetal loss, neonatal meningitis, and neonatal death1,2
Perinatal listeriosis can be asymptomatic or present with gastrointestinal symptoms, myalgias, fevers, sepsis, and acute respiratory distress syndrome.1,3 In pregnancy, 29% of patients with invasive listeriosis experience fetal loss or neonatal death.2
Pregnant people should avoid foods at high risk of Listeria monocytogenes contamination2,4
Whereas certain foods have higher contamination risk (e.g., unpasteurized milk and cheeses, luncheon meats, refrigerated meat spreads, and premade salads),2,5 it is important to also be aware of Health Canada recalls (https://recalls-rappels.canada.ca/en). Most exposures do not result in symptoms, but listeriosis is 20 times more common in pregnancy.5,6
In asymptomatic patients who have ingested possibly contaminated foods, investigations or treatment are not indicated2,5
Because the incubation period is up to 70 days, listeriosis can present 2–3 months after exposure.5 If symptoms develop, patients should be managed based on the recommendations below.
In afebrile patients presenting with mild gastroenteritis or flulike symptoms with possible exposure to L. monocytogenes, investigations and management are guided by expert opinion2
Whereas expectant management is reasonable, obtaining blood cultures2 and/or starting a 14-day course of oral amoxicillin (500 mg 3 times daily)4,5 could be considered. Patients with resolved symptoms should be treated as asymptomatic.
In febrile patients with possible exposure to L. monocytogenes, blood cultures should be immediately drawn and high-dose ampicillin initiated, with electronic fetal heart rate monitoring2,4
Intravenous ampicillin (6–12 g/d) should be given for 14 days with consideration for synergistic gentamicin.2 Trimethoprim with sulfamethoxazole should be used in patients with penicillin allergy.2,4 If delivery occurs, placental culture and pathology should be completed. Pediatric care providers should be informed to consider empiric antibiotics, laboratory investigations, cerebrospinal fluid sampling, and imaging.2
Footnotes
Competing interests: None declared.
This article has been peer reviewed.
References
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