Salmonellosis

What is salmonellosis?

Salmonellosis is an infection with bacteria called Salmonella. Salmonella can cause different types of illnesses:

• food poisoning (gastroenteritis)
• blood poisoning (bacteremia)
• typhoid fever (a life-threatening illness common in many less-developed parts of the world).

These different kinds of illnesses are all caused by eating food or drinking water or other liquids contaminated with salmonella bacteria. Food poisoning causing a stomach flulike illness is the most common type of salmonellosis in the US.

Salmonellosis can be very serious for very young children, older adults, or people with a weakened immune system.

How does it occur?

Salmonella bacteria can live in the intestinal tract of animals and humans. They can produce poison (called toxins), which can cause illness. The infection most often happens when you eat food that has not been properly prepared or stored. Food that may be contaminated with Salmonella bacteria needs to be heated to a temperature that is high enough to destroy the toxins. If the food is not heated enough before it is eaten, it can make you sick.

People most often get salmonellosis from eating food contaminated with an animal's bowel movements (feces). Foods most likely to have Salmonella bacteria are:

• milk and dairy products
• eggs
• poultry
• meat, including processed meats.

Food can also get contaminated when someone who is infected prepares food without washing their hands with soap and water after using the bathroom. Contaminated food usually looks and smells normal.

Pets such as dogs, cats, and turtles can also spread the disease.

What are the symptoms?

Symptoms of food poisoning include:

• diarrhea (which may contain blood), lasting 3 to 5 days
• fever and chills
• nausea and vomiting
• abdominal cramps.

You may start feeling sick 12 hours to 3 days after eating contaminated food.

Symptoms of salmonella bacteremia include:

• fever that comes and goes over several days
• pain in the joints and around the heart and lungs.

Bacteremia is most common in people who do not have a strong immune system.

Symptoms of typhoid fever are more varied and affect the whole body. They include:

• headache
• sore throat
• cough
• fever
• rash
• diarrhea or constipation.

The symptoms of typhoid fever may not begin for 1 to 2 weeks after your exposure to salmonella.

How is it diagnosed?

Your healthcare provider will ask about your symptoms and examine you. He or she will check your temperature and examine you to see if your abdomen is tender. Your provider will check for dehydration (severe loss of body fluids). Samples of your blood, bowel movement, and urine may be tested.

How is it treated?

Treatment for food poisoning involves controlling your symptoms. The goal is to stop the vomiting and diarrhea and prevent dehydration. If you are undernourished, severely ill, very young, or have sickle cell disease, your provider may prescribe an antibiotic. Otherwise, antibiotics are not routinely prescribed. If you are severely dehydrated, you may need to be treated at the hospital.

Treatment for blood poisoning and typhoid fever requires antibiotics. Depending on how ill you are, you may be able to take your medicine by mouth or you may need intravenous (IV) antibiotics and hospitalization.

How long will the effects last?

Salmonella food poisoning usually lasts 3 to 5 days. You can continue to carry the disease after you've been infected, whether or not you have symptoms. However, this is not usually a permanent condition.

Blood poisoning and typhoid fever are more serious illnesses. The symptoms tend to be more severe and the treatment may take 2 weeks.

How can I take care of myself?

It is particularly important to follow the treatment plan your healthcare provider prescribes. Ask your provider if you can take aspirin, acetaminophen, or ibuprofen to control your fever. Keep a daily record of your temperature.

If you have cramps or stomach pain, it may help to put a hot water bottle or electric heating pad on your stomach. Cover the hot water bottle with a towel or set the heating pad at low to prevent burns.

You may want to let your bowel rest for a few hours by drinking only clear liquids such as water, weak tea, bouillon, apple juice, or sports drinks or other oral rehydrating solutions. You may also drink soft drinks without caffeine (such as 7 UP) after letting them lose some of their carbonation (go flat). Make sure you drink often, even if only an ounce or two, so that you do not become dehydrated. Becoming dehydrated can be very dangerous, especially for children, older adults, and some people who have other medical problems. Suck on ice chips or Popsicles if you feel too nauseated to drink fluids.

It is OK to keep eating as long as it does not seem to worsen the diarrhea or stomach cramps. Foods that are easiest to digest are soft starchy foods, such as bananas, cooked cereal, rice, plain noodles, gelatin, toast or bread with jelly, and applesauce. Avoid milk products and caffeine for a few days. Return to your normal diet after 2 or 3 days, but for several days avoid fresh fruit (other than bananas), alcohol, greasy or fatty foods such as cheeseburgers or bacon, highly seasoned or spicy foods, and most fresh vegetables. Cooked carrots, potatoes, and squash are fine. If eating seems to worsen the diarrhea, let your bowel rest for a few hours by drinking just clear liquids.

Be cautious about taking nonprescription antidiarrheal medicines such as Kaopectate or Imodium or the prescription medicine Lomotil. These medicines can actually make the illness more severe, especially if the diarrhea is bloody. If you take one of these medicines, make sure you use only the dose recommended on the package. If you have chronic health problems, always check with your healthcare provider before you use any medicine for diarrhea.

How can I help prevent salmonellosis?

Salmonella bacteria are killed by cooking food thoroughly. Make sure you cook all foods well, especially beef, chicken, turkey, pork, seafood, and eggs. Wash your hands with soap and very warm water before and after handling food. Always clean kitchen counters thoroughly after each use. Refrigerate foods soon after purchase and thaw meat properly before cooking. When thawing meat, move it from the freezer to the refrigerator 1 or 2 days before you plan to cook it. Do not thaw meat and poultry at room temperature. Use only pasteurized milk and dairy products.

Always wash your hands after using the bathroom, changing diapers, or handling pets.

Get immunized against typhoid fever before traveling outside the US according to the recommendations of the Centers for Disease Control and Prevention (CDC) for the countries where you will be going. Also get immunized if a member of your household carries the disease. The typhoid vaccine comes in 2 forms: oral and injection. Both forms are effective. The single-dose shot may give mild side effects, namely, soreness at the site of the shot and, less often, mild fever or headache. The oral vaccine consists of 4 capsules that must be taken every other day until they are gone. Usually there are no side effects from the capsules.

Ask your healthcare provider about drugs for preventing and treating traveler's diarrhea. In addition, when traveling in other countries, you may want to:

• Drink only bottled water and liquids. Avoid tap water and ice.
• Avoid eating unpeeled fruits. Eat fruits you peel yourself.
• Avoid eating uncooked vegetables (such as raw leafy vegetables) and other foods stored or served at room temperature.
• Ask how food is being prepared. Avoid poultry, meat, and eggs, and other foods that have not been refrigerated or cooked thoroughly.
• Choose recently prepared foods, served hot or chilled.
• Wash your hands regularly with soap and very warm water.
• Be especially careful to wash foods you are preparing and to clean cooking utensils well.

For more information, see the CDC's Traveler's Health Web site: http://wwwn.cdc.gov/travel.