Listeria Infection – Diagnosis and Treatment
Diagnosis
Doctors usually check for listeria by doing a blood test. Sometimes, they test spinal fluid or, for pregnant women, the fluid around the baby.
These tests help doctors find Listeria monocytogenes in the body. Lab results show if a person has listeriosis or related complications.
In most cases, a blood culture is the first and most reliable way to detect the infection. If meningitis is suspected, a lumbar puncture (spinal tap) may be done to collect and examine cerebrospinal fluid.
In pregnant individuals, doctors may also test amniotic fluid or placental tissue if there are concerns about the baby’s health.
Once the bacteria are identified, doctors can confirm the diagnosis and start treatment—usually with antibiotics like ampicillin. Prompt testing and diagnosis are crucial, especially for high-risk individuals such as pregnant women, newborns, the elderly, or those with weakened immune systems.
Treatment
Most mild cases of listeria infection do not need special treatment. The immune system often clears the infection on its own within a few days. Rest, fluids, and a balanced diet can support recovery during this time.
For more serious or invasive cases—such as when the infection spreads to the bloodstream or brain—doctors typically use intravenous antibiotic therapy.
This is especially important for vulnerable groups such as older adults, people with weakened immune systems, pregnant individuals, and newborns.
Hydration is key to recovery, particularly if the person experiences fever or diarrhea. Pregnant individuals with confirmed or suspected listeriosis are treated promptly to reduce the risk of complications, including transmission to the fetus.
Newborns infected during delivery may receive hospital-based care, including intravenous medications and supportive treatments. People with weakened immunity may need longer or more intensive therapy based on the severity of the infection.
Getting Ready for Your Medical Visit
Steps You Can Take Beforehand
Make a List: Write down any symptoms and when they began.
Note Key Details: Share if you are pregnant and how far along you are.
Medical History: List any health conditions and all medications or supplements you use.
Track Foods Eaten: Create a food diary. Include details on meats, dairy products, vegetables, fruits, and any refrigerated or ready-to-eat foods recently eaten.
Let your provider know if you’ve had soft cheeses, unpasteurized or raw milk products, smoked seafood, or products from recent food recalls.
- Food Safety Practices: Mention if you check refrigerator temperature or take steps to avoid cross-contamination.
| Items to Bring | Details Needed |
|---|---|
| Symptom list | Start date & severity |
| Food diary | Include recalled foods |
| Medication list | Prescription & over-the-counter |
| Pregnancy status | How far along |
Possible Questions from Your Healthcare Provider
Doctors often ask about certain foods you have eaten.
They may ask if you have eaten:
- Soft cheeses (like brie or feta)
- Mexican-style cheeses (queso fresco)
- Unpasteurized milk or cheeses
- Processed meats (hot dogs, deli meats)
- Any recalled foods
Be honest and specific when you answer.
This helps your provider decide the next steps for prevention and treatment.
