Listeriosis

What is listeriosis?

Listeriosis is a serious infection usually caused by eating food contaminated with the bacterium Listeria monocytogenes. The disease primarily affects older adults, pregnant women, newborns and adults with weakened immune systems. However, rarely, people without these risk factors can also be affected.

What are the symptoms?

Patients usually have a fever and muscle aches, preceded by diarrhea or other gastrointestinal symptoms. Almost everyone diagnosed with listeriosis has "invasive" infection, in which the bacteria spread beyond the gastrointestinal tract. The symptoms vary with the infected person:

• Pregnant women typically experience fever and other non-specific symptoms, such as fatigue and aches. However, infections during pregnancy can lead to miscarriage, stillbirth, premature delivery or life-threatening infection of the newborn.
• People other than pregnant women typically experience symptoms including headache, stiff neck, confusion, loss of balance and convulsions in addition to fever and muscle aches.
  

How do you get it?

Most human infections result from eating contaminated foods. Vegetables can become contaminated from the soil and manure used as fertilizer. Animals can carry the bacterium and contaminate meat and dairy products. Outbreaks have been linked to ready-to-eat foods (such as hot dogs, luncheon meats, cold cuts, fermented or dry sausage, and other deli-style meat and poultry), a variety of raw foods (such as uncooked meats and vegetables) and unpasteurized (raw) milk or foods made from unpasteurized milk.

How is it treated?

Listeriosis is treated with antibiotics. High-risk people who experience fever and other non-specific symptoms after eating contaminated food should seek medical care and tell the health care provider about eating contaminated food. Even with prompt treatment, some listeriosis cases result in death.

How to reduce your risks?

Risks can substantially be reduced by carefully following food safety precautions. Thorough cooking will destroy Listeria on foods. High risk people should refrain from eating deli items, unless they are reheated until steaming hot. They should avoid soft cheeses; refrigerated pâtés or meat spreads, and smoked seafood (often labeled as "nova-style," "lox," "kippered," "smoked," or "jerky"), unless it is in a cooked dish.

How do I protect others from listeriosis?

• Wash hands, knives, and cutting boards after preparing uncooked foods.
• Wash all raw vegetables or fruit thoroughly before eating.
• Keep raw and cooked foods separate.
• Thoroughly cook all food of animal origin, including eggs.
• Cook raw meat to an internal temperature of 160 degrees Fahrenheit, raw poultry to 180 degrees Fahrenheit and raw fish to 160 degrees Fahrenheit.
• Keep hot foods above 140 degrees Fahrenheit.
• Keep cold foods below 40 degrees Fahrenheit.
  
• Reheat leftovers thoroughly.