Definition Listeriosis (lis-ter-ee-oh-sis) is a bacterial infection that strikes humans and animals.
What is going on in the body? The Listeria bacteria are found in many places and often passed on to humans in certain foods. Unpasteurised milk and milk products, undercooked meats and raw vegetables and fruits may all be contaminated with Listeria bacteria. Babies may become infected with the bacteria if their mothers are infected during pregnancy or during birth.
What are the signs and symptoms of the infection? Listeriosis can cause no symptoms in otherwise healthy people. But infection with the bacteria can cause:
fever
headache
vomiting
diarrhoea
Children, the elderly and people with weakened immune systems may have more serious reactions to infection with the bacteria, such as meningitis (men-in-jie-tis), or inflammation of the membranes surrounding the brain and spinal cord.
Disease can occur during the first few days of a baby's life or after the first week of life. Babies who have been infected with the bacteria usually get bacterial infection in the blood, and meningitis is also common among infected infants. These are sometimes fatal.
What are the causes and risks of the infection? The Listeria bacteria cause listeriosis. It is spread by contaminated foods or from an infected mother to her baby during pregnancy or birth.
What can be done to prevent the infection?
Pregnant women who become infected with Listeria may be given antibiotics to keep it from spreading to their babies.
Pregnant women and people with weakened immune systems should avoid unpasteurised milk or milk products and eat only well cooked meat. They should also wash fruits and vegetables well.
How is the infection diagnosed? The bacteria can be cultured (grown in the lab) from infected body fluids and wastes, such as blood, cerebrospinal fluid and faeces.
What are the long-term effects of the infection? The infection can cause serious health problems and even death in newborns and people with weakened immune systems.
What are the risks to others? A pregnant woman can pass listeriosis on to her baby.
What are the treatments for the infection? Combination therapy with ampicillin and gentamicin is the first choice for treating a severe infection.
What are the side effects of the treatments?
Ampicillin can cause rash or an allergic reaction.
gentamicin can harm the kidneys and ears.
Author: Danielle Zerr, MD Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request
