From the Research
Introduction to Listeriosis
Listeriosis is an infective complication that primarily affects pregnant women, patients at extremes of age, or those with weakened immune systems 1. The symptoms of listeriosis can vary depending on the severity of the infection and the individual's immune status.
Symptoms of Listeriosis
The symptoms of listeriosis can be divided into two categories: mild and invasive. Mild illness presents as gastroenteritis with fever, diarrhea, nausea, and vomiting common in the 7 days post-exposure 1. Invasive infection, characterized by bacteremia and encephalitis, can develop in high-risk patients 1. Fetal loss is a major complication of listeriosis during pregnancy 1, 2.
Maternal Symptoms
Maternal listeriosis during pregnancy usually presents as a mild febrile illness 2. Symptoms may include:
- Fever
- Fatigue
- Flu-like symptoms
Fetal and Neonatal Symptoms
Fetal listeriosis has a high mortality rate and can cause:
- Miscarriage
- Spontaneous preterm labor
- Preterm birth
- Stillbirth
- Congenital neonatal infections 2, 3 Neonatal listeriosis may present as sepsis or meningitis with severe sequelae and high case fatality rate 2.
Treatment and Prevention
Treatment of listeriosis typically involves antibiotic therapy. Penicillin-based therapy, such as high-dose penicillin or amoxicillin, in combination with gentamicin, is advised for invasive infection 1. Co-trimoxazole may be considered for patients intolerant to penicillin 1. Amoxicillin or ampicillin are the first line of treatment alone or in combination with gentamicin, followed by trimethoprim/sulfamethoxazole 2.
Prevention Strategies
Prevention remains the best way to control listeriosis and should be reinforced among patients, healthcare professionals, and regulatory agencies 2, 3. Vulnerable individuals, notably pregnant women, should be counseled on appropriate preventative strategies, including:
- Avoiding foods commonly contaminated with L. monocytogenes, such as soft ripened cheeses, pate, cooked chilled meats, unpasteurized milk, and ready-to-eat poultry unless thoroughly cooked 1
- Reheating leftovers until steamed
- Avoiding unpasteurized dairy products 3
Caveats and Differentials
It is essential to consider listeriosis as a cause of fever during pregnancy and initiate appropriate treatment preemptively 2. Listeriosis can be difficult to diagnose due to non-specific symptoms, and a high index of suspicion is required, particularly in high-risk individuals 4.