Health Topics for Infectious Diseases

Department of Internal Medicine: Infectious Diseases

Department of Internal Medicine: Travel Medicine

Salmonella infection

A bacteria called Salmonella causes an infection called salmonellosis. The infection can be localized to the gastrointestinal tract (gastroenteritis or food poisoning). It can also be a systemic, or a body-wide infection resulting in typhoid fever. Occasionally Salmonella results in a localized infection outside the GI tract.

Gastroenteritis, or food poisoning, is the most common type of Salmonella infection. It results from the toxin of intestinal bacteria that live in animals and humans. The most common cause is eating improperly prepared or stored foods. It is not the Salmonella bacteria, but its toxins (byproducts), that cause illness. Anything contaminated with Salmonella bacteria, that is not heated to a high enough temperature to destroy the toxins before being eaten, may cause illness. The infection can have a very serious affect on very young children, elderly adults, or those with a weakened immune system.

The symptoms of salmonella food poisoning begin within 6 to 72 hours and may include:

• abdominal pains or cramps
• diarrhea
• nausea and vomiting and
• fever

It is usually diagnosed, based on medical history and physical exam. Occasionally, stool cultures and blood tests may be done.

Salmonella lives in the intestinal tract (bowels) of all people and animals. People usually get salmonella from eating foods contaminated with animal or human feces (bowel movements). Food also gets contaminated when someone does not wash their hands with soap and water after using the bathroom and then prepares food. The contaminated food may look and smell normal.

Some common sources of salmonella infection include:

• undercooked or raw chicken and eggs
• raw or unpasteurized milk and dairy products
• meat and processed meat products

Salmonella is also found in the feces of pets, especially turtles, lizards, and other reptiles. It is very important to wash your hands after handling these animals or their feces.

There are many steps you can take to prevent salmonella infection:

• wash hands before preparing and eating foods, after using the bathroom or changing diapers, and after handling pets
• refrigerate foods soon after purchase
• check expiration dates on food labels and packages and dispose of all outdated food
• drink only pasteurized milk products and
• clean all food preparation areas before and after preparing food with a solution of diluted bleach and water

People, especially children, should not eat raw or undercooked eggs because they may contain Salmonella. Raw eggs may be unrecognized in some foods such as homemade hollandaise sauce, caesar and other salad dressings, eggnog, homemade ice cream, homemade mayonnaise, cookie dough, and some frostings. Do not eat eggs that are prepared sunny side up. Poultry and meat, including hamburgers, should be well-cooked and not pink in the middle. If you are served undercooked meats, poultry or eggs send it back to the kitchen for further cooking. Outbreaks have also been linked to seed sprouts, such as alfalfa and mung beans, whether grown at home or for stores.

When you are preparing foods, avoid cross-contamination. Keep uncooked meats separate from produce, cooked foods, and ready-to-eat foods. Make sure to wash the cutting boards, knives and other utensils thoroughly with soap and water after the raw meat has been on the surface. Wash your hands after handling any uncooked foods.

Your local health department needs to know if you or someone has salmonella food poisoning. They will ask where you have eaten and what you have eaten. If they learn of many cases at the same time, it may mean that a restaurant, grocery store, or a food or water source has a problem.

Salmonella is treated by dealing with the symptoms, such as diarrhea. It is important to follow all treatment instructions to avoid complications, such as dehydration.

Typhoid, the most severe form of salmonellosis, usually lasts from 1 to 4 weeks. The mortality rate is about 3 percent for persons who are treated and 10 percent for those who are not. The incidence is increasing in the United States as a result of people returning from endemic countries.

Before traveling out of the United States, get advice from a healthcare provider about eating and drinking water in the foreign country you are going to be visiting.

Last Reviewed 2005

Disclaimer: This content is reviewed periodically and is subject to change as new health information becomes available. The information provided is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional. HIL File Infe4729.RF2 V Copyright 19

HIL File Infe4729.RF2 VRS# 4729 Data Version 7.0 Copyright 1998, 2002-2003 McKesson Health Solutions LLC. All rights reserved.