A 25-year-old woman, gravida 1 para 0, at 24 weeks gestation comes to labor and delivery due to decreased fetal movement. The patient has felt decreased fetal movement for the past day and no fetal movement in the past hour. She has had no contractions, vaginal bleeding, or leakage of fluid. Last week, the patient went to a picnic and the next day she had nausea, watery diarrhea, and muscle aches, but no rashes or joint pain. Her symptoms resolved after 24 hours. She has no chronic medical conditions and takes no daily medications. Temperature is 98.9 F (37.2 C), blood pressure is 118/68 mm Hg, and pulse is 90/min. Cardiopulmonary examination is normal. There is no flank pain and the uterus is nontender. On pelvic examination, the cervix is closed, and membranes are intact. No fetal heart tones are detected on Doppler, and a transabdominal ultrasound confirms an intrauterine fetal demise. Which of the following pathogens is the most likely cause of this patient's presentation?
Listeria monocytogenes | |
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CSF = cerebrospinal fluid. | |
This patient with intrauterine fetal demise in the setting of a recent episode of watery diarrhea likely had a foodborne infection due to Listeria monocytogenes. L monocytogenes is a facultative intracellular anaerobe that typically causes outbreaks via ingestion of contaminated foods (eg, deli meats). The bacteria can replicate at cold temperatures (eg, refrigeration) and invade the intestinal mucosa once ingested, causing gastroenteritis (eg, fever, vomiting, diarrhea).
Most infections in healthy patients are self-limited; however, pregnant women (who are relatively immunosuppressed) are at increased risk of invasive disease (eg, bacteremia) and fetal infection via transplacental transmission. Infection acquired in early pregnancy (eg, first and second trimesters) typically results in granulomatosis infantiseptica (ie, disseminated abscesses/granulomas) and possible intrauterine fetal demise. Infection in the third trimester may be less severe and present as fetal distress, preterm delivery, or early-onset neonatal sepsis.
Therefore, pregnant patients are advised to avoid foods commonly contaminated with L monocytogenes such as raw meats and vegetables, unpasteurized dairy products, and processed (eg, deli) meats. In addition, proper handwashing after handling soil or decaying vegetation (eg, gardening) is recommended.
(Choice A) Early infection with Borrelia burgdorferi (ie, Lyme disease) typically presents with erythema migrans rather than gastroenteritis. In addition, adverse fetal effects are uncommon.
(Choice B) Group B Streptococcus can cause intrauterine fetal demise; however, pregnant women are usually asymptomatic or have urinary tract infections rather than gastroenteritis.
(Choice D) Parvovirus B19 infection can cause intrauterine fetal demise; however, this diagnosis is less likely because it is not spread via contaminated food. In addition, maternal infection typically causes arthralgias and arthritis (particularly of the small joints) and rash (not seen in this patient).
(Choice E) Staphylococcus aureus is a rare cause of intrauterine fetal demise and gastrointestinal symptoms. Patients typically have gastroenteritis dominated by nausea and vomiting (rather than diarrhea), making this diagnosis less likely.
Educational objective:
Listeria monocytogenes is a common foodborne infection due to consumption of contaminated food (eg, unpasteurized milk, deli meats) and typically causes a self-limited gastroenteritis. During pregnancy, L monocytogenes can cause transplacental fetal infection and possible intrauterine fetal demise.