Summary about Disease
Listeriosis is a serious infection usually caused by eating food contaminated with the bacterium Listeria monocytogenes. It primarily affects pregnant women, newborns, older adults, and people with weakened immune systems. While relatively rare, listeriosis can be fatal, particularly in high-risk groups.
Symptoms
Symptoms vary depending on the person and the severity of the infection.
Invasive listeriosis (more serious): High fever, muscle aches, stiff neck, headache, confusion, loss of balance, and convulsions. Sometimes preceded by diarrhea or other gastrointestinal symptoms. In pregnant women, it can cause miscarriage, stillbirth, premature delivery, or life-threatening infection of the newborn.
Non-invasive listeriosis (less serious, typically foodborne): Diarrhea and fever.
Causes
Listeriosis is caused by eating food contaminated with Listeria monocytogenes. Common sources include:
Raw or unpasteurized milk and dairy products
Soft cheeses (e.g., feta, brie, Camembert)
Ready-to-eat deli meats and hot dogs
Smoked seafood
Raw sprouts
Poorly processed or stored foods The bacteria can survive and even grow at refrigerator temperatures. Contamination can occur at any stage of food processing.
Medicine Used
Antibiotics are used to treat listeriosis. The specific antibiotics used and the duration of treatment depend on the severity of the infection and the individual's health status. Common antibiotics include:
Ampicillin
Gentamicin (often used in combination with ampicillin)
Trimethoprim-sulfamethoxazole (Bactrim)
Is Communicable
Listeriosis is generally not considered communicable from person to person, except in the case of a pregnant woman passing the infection to her fetus. It is primarily acquired through contaminated food.
Precautions
Food Safety:
Cook meats and poultry thoroughly.
Wash raw vegetables and fruits thoroughly.
Keep raw meats separate from vegetables, cooked foods, and ready-to-eat foods.
Avoid unpasteurized milk and products made from it.
Heat ready-to-eat foods, such as hot dogs and deli meats, until steaming hot before eating.
Wash hands thoroughly after handling food.
Clean refrigerators regularly.
High-Risk Individuals (Pregnant women, older adults, immunocompromised individuals):
Avoid soft cheeses (feta, brie, Camembert, blue-veined cheeses) unless they are labeled as made with pasteurized milk.
Avoid ready-to-eat deli meats and hot dogs unless they are reheated until steaming hot.
Avoid refrigerated smoked seafood.
Avoid raw sprouts.
How long does an outbreak last?
The duration of a listeriosis outbreak varies depending on the source and the effectiveness of control measures. Outbreaks can last from a few weeks to several months. Once the contaminated food source is identified and removed from the market, the number of new cases typically declines rapidly.
How is it diagnosed?
Listeriosis is diagnosed by:
Blood culture: A sample of blood is tested for the presence of Listeria monocytogenes.
Cerebrospinal fluid (CSF) culture: If meningitis is suspected, a sample of CSF is tested.
Placenta, amniotic fluid, or newborn's blood culture: In pregnant women with suspected listeriosis.
Stool culture: Sometimes used, especially in cases of non-invasive listeriosis.
Timeline of Symptoms
The incubation period for listeriosis (the time between eating contaminated food and the onset of symptoms) varies:
Invasive listeriosis: Can range from a few days to several weeks (typically 1-4 weeks, but sometimes up to 70 days).
Non-invasive listeriosis (gastroenteritis): Shorter incubation period, usually a few hours to 2-3 days. Symptoms typically last for several days to weeks, depending on the severity of the infection and the individual's response to treatment.
Important Considerations
Listeriosis is a serious infection, especially for high-risk groups. Prompt diagnosis and treatment are crucial.
Pregnant women should be particularly vigilant about food safety precautions to prevent listeriosis, as it can have devastating consequences for the fetus.
Public health agencies play a vital role in investigating and controlling listeriosis outbreaks.
Reporting suspected cases of listeriosis to public health authorities is important for identifying and preventing further infections.