Listeriosis is a rare but serious infectious disease caused by the bacterium Listeria monocytogenes, which is predominantly transmitted to humans through the consumption of contaminated food. Clinical syndromes associated with listeriosis include febrile gastroenteritis, invasive disease (sepsis, meningitis, meningoencephalitis), and fetal infections causing spontaneous abortions, stillbirth, premature labor, and neonatal disease. Approximately 20% of listeriosis cases are fatal. Listeriosis most often affects unborn fetuses, newborn infants, older adults, and individuals with weakened immune systems. Prompt recognition and treatment of the disease are necessary to avoid several serious complications.

Symptoms might begin a few days after you've eaten contaminated food, but it can take 30 days or more before the first signs and symptoms of infection begin.

If the listeria infection spreads to your nervous system, signs and symptoms can include:

• Headache
• Stiff neck
• Confusion or changes in alertness
• Loss of balance
• Convulsions

Symptoms during pregnancy and in newborns

During pregnancy, a listeria infection is likely to cause only mild signs and symptoms in the mother. The consequences for the baby, however, can be devastating — the baby can die in the womb or have a life-threatening infection within a few days of being born.

Signs and symptoms of a listeria infection in a newborn can be subtle, but can include:

• Little interest in feeding
• Irritability
• Fever
• Vomiting
• Difficulty breathing

Listeria bacteria can be found in soil, water and animal feces. People can get infected by eating the following:

• Raw vegetables that have been contaminated from the soil or from contaminated manure used as fertilizer
• Contaminated meat
• Unpasteurized milk or foods made with unpasteurized milk
• Certain processed foods — such as soft cheeses, hot dogs and deli meats that have been contaminated after processing

Unborn babies can contract a listeria infection from the mother.

Treatment of listeria infection varies, depending on the severity of the signs and symptoms. Most people with mild symptoms require no treatment. More-serious infections can be treated with antibiotics.

During pregnancy, prompt antibiotic treatment might help keep the infection from affecting the baby.

Pregnant women and people who have weak immune systems are at highest risk of contracting a listeria infection.

Pregnant women and their babies

Pregnant women are much more susceptible to listeria infections than are other healthy adults. Although a listeria infection might cause only a mild illness in pregnant women, consequences for their babies can include:

• Miscarriage
• Stillbirth
• Premature birth
• A potentially fatal infection after birth

People who have weak immune systems

This category includes people who:

• Are older than 65
• Have AIDS
• Are receiving chemotherapy
• Have diabetes or kidney disease
• Take high-dose prednisone or certain rheumatoid arthritis drugs
• Take medications to block rejection of a transplanted organ

Neonatal listeriosis is a listeria infection acquired trans placentally or during or after delivery. Diagnosis is made by culture or polymerase chain reaction testing of mother and infant.

Treatment of Neonatal Listeriosis
1. Listeriosis is commonly treated with antibiotics.
2. The most commonly prescribed treatment is intravenous ampicillin.
3. Antibiotic gentamicin in combination with ampicillin is also recommended by most physicians.
4. People who cannot tolerate B-lactam antibiotics (such as ampicillin), will be prescribed trimethoprim-sulfamethoxazole as an alternative.
5. Other antibiotics are sometimes recommended.
6. Antibiotic treatment of pregnant women with documented listeriosis may prevent fetus infection.
7. Other possible drugs include ampicillin or penicillin with rifampin or trimethoprim/sulfamethoxazole, trimethoprim/sulfamethoxazole alone, and meropenem, but they have not been well evaluated.
8. Other treatments are symptomatic and supportive.

Prevention of Neonatal Listeriosis
1. Pregnant women should avoid food products with a higher risk of contamination by L. monocytogenes (eg, unpasteurized dairy products, soft cheeses, raw vegetables, prepared deli meats and salads, refrigerated meat spreads, or smoked seafood).
2. Proper food handling, in particular separating uncooked meats from other items during preparation and washing hands, utensils, and cutting boards after handling uncooked foods, is critical.
3. If infection during pregnancy is recognized, treatment may then be given before delivery or intrapartum to prevent vertical transmission, but the usefulness of such treatment is unproven.

Symptoms
Fever,Lethargy,Irritability,Diarrhea,Poor feeding,Vomiting,Respiratory distress,Skin rash consisting of widely spread, small, pale nodules (granulomatosis infantiseptica)
Conditions
Febrile gastroenteritis,Invasive disease (sepsis, meningitis, meningoencephalitis),Fetal infections causing spontaneous abortions, stillbirth, premature labor, and neonatal disease
Drugs
Intravenous ampicillin,Trimethoprim-sulfamethoxazole