Alternative Names samonellosis, Salmonella food poisoning, Salmonella gastro-enteritis Definition Salmonella (sal-ma-nel-ah) infections are caused by a bacterium.
What is going on in the body? These infections occur worldwide. People acquire the Salmonella bacteria from one another or from animals by:
having direct or indirect contact with the faeces of an infected person or animal
eating or drinking tainted food or water
Many animals may carry this bacteria, including cats, dogs, livestock, fish, birds, rodents, reptiles, and amphibians. Children younger than 5 and adults older than 70 are more susceptible to the disease. Children younger than 1 who develop the infection often have more severe symptoms.
What are the signs and symptoms of the infection? Most people who develop the infection will not have any symptoms. Symptoms that do occur are usually similar to symptoms of gastroenteritis. This term describes inflammation of the stomach and intestines that commonly causes stomach upset and/or vomiting and diarrhoea. Symptoms usually start 24 to 72 hours after contact. Symptoms may last from 2 to 5 days, with diarrhoea lasting up to 2 weeks. The symptoms are:
Sometimes the bacteria can enter the bloodstream causing very high fever and low blood pressure. From the bloodstream, the bacteria may spread to other parts of the body, such as the brain, bones, and other organs. This often happens in infants with the infection.
Typhoid, usually caused by a specific type of Salmonella known as Salmonella typhi, has a slow onset of symptoms including:
What are the causes and risks of the infection? There are many species of Salmonella that cause this infection.
The risk of acquiring this infection is increased by:
having close contact with the faeces of infected people or animals.
drinking tainted water.
eating contaminated food that has been improperly handled or only partially cooked.
having a weakened immune system. This may occur with certain cancers, such as leukaemia, a cancer of the blood, or AIDS, which is due to a severe infection with HIV.
having liver disease.
using antacids.
having stomach surgery.
What can be done to prevent the infection? There are a few ways to help prevent this infection.
Hands should be washed with soap after changing nappies or using the toilet.
Hands should washed with soap after touching animals and animal products, such as eggs.
Meat should be cooked thoroughly before eaten.
Certain pets, such as turtles and other reptiles, should not be kept in homes with young children.
People are advised to get the Salmonella typhi vaccine before travel to certain areas. Parts of Latin America, Asia, and Africa, for example, may have food and water that are contaminated.
Public health measures are important in food processing plants. Outbreaks affecting thousands of people have occurred from a single dirty machine.
How is the infection diagnosed? Salmonella can be identified in the stool, blood, urine, or pus. In severe cases, it may found in the clear fluid surrounding the brain and spinal cord, called cerebrospinal fluid.
What are the long-term effects of the infection? These infections usually have no long-term effects. Recovery takes less than a week in most cases. However, in infants and people with weak immune systems, more severe infections are possible. In these cases, infections may involve the brain or heart and result in death or serious organ damage.
What are the risks to others? This infection can easily be spread to others. People caring for children or preparing food should follow the rules of good hygiene.
What are the treatments for the infection? Doctors suggest that people with mild cases allow the disease to run its course without using medications. The main treatment in this case is drinking fluids to prevent dehydration. Some people are not able to keep any liquids down. Such people may need fluids given to them through an IV tube in their arm.
Young children and anyone with a weakened immune system may need drug treatment. Severe cases of this infection are treated with antibiotics such as trimethoprim-sulfamethoxazole or ciprofloxacin.
What are the side effects of the treatments? All medications have possible side effects. Antibiotics may cause allergic reactions, stomach upset, and other side effects. Specific side effects depend on the drugs used.
What happens after treatment for the infection? After this infection, people often shed the bacteria in their stool for more than a month. Good hygiene is important to avoid giving the infection to others. Children in daycare and workers who handle food may be banned from such until their stool no longer contains the bacteria.
How is the infection monitored? In most cases, monitoring can be done at home. Affected people need to drink a lot of fluids to avoid dehydration. In more severe cases, or when a person cannot keep any liquids down, people may need to be monitored in the hospital.
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
