What Is Salmonella?

Salmonella is a kind of bacteria, with many different types. The type responsible for most infections in humans is carried by chickens, cows, pigs, and reptiles (such as turtles, lizards, and iguanas). Another, rarer form — called Salmonella typhi — causes typhoid fever.

What Is Salmonella Infection?

Salmonella infection, or salmonellosis, is a foodborne illness caused by infection with Salmonella bacteria. Most infections spread to people through contaminated food (usually meat, poultry, eggs, or milk).

What Are the Signs & Symptoms of Salmonella Infection?

A Salmonella infection typically causes:

Because many different kinds of illnesses can cause these symptoms, most doctors will take a stool sample to make an accurate diagnosis.

Salmonella infections usually clear up without medical treatment.

How Do People Get Salmonella Infections?

Salmonella bacteria are often found in the feces (poop) of some animals, particularly reptiles. People who have these animals as pets can get salmonellosis if they handle the reptiles and get the bacteria on their hands.

Salmonella can spread to people in foods contaminated by infected animal feces. This can happen when foods such as poultry, eggs, and beef are not cooked enough. Fruit and vegetables can also be contaminated from feces in the soil or water where they're grown.

Are Salmonella Infections Contagious?

Yes. People with salmonellosis can spread the infection from several days to several weeks after they've been infected — even if their symptoms have disappeared or they've been treated with antibiotics.

Who Is at Risk for Salmonella Infections?

Not everyone who ingests Salmonella bacteria will become ill. Children, especially infants, are most likely to get sick from it. About 50,000 cases of salmonellosis are reported in the United States each year and about one third of those are in kids 4 years old or younger.

People at risk for more serious complications from a Salmonella infection include those who:

  • are very young, especially babies
  • have problems with their immune systems (such as people with HIV)
  • take cancer-fighting drugs or drugs that affect their immune system
  • have sickle cell disease
  • have an absent or nonfunctioning spleen
  • take chronic stomach acid suppression medicine

In these higher-risk groups, most doctors will treat an infection with antibiotics to prevent it from spreading to other parts of the body. Antibiotics do not appear to help a healthy person whose infection is not severe — and may actually lengthen the amount of time the person will carry the bacteria.

How Are Salmonella Infections Diagnosed?

Because many different illnesses can cause similar symptoms (such as nausea, fever, cramping, and diarrhea), doctors may send a stool (poop) sample to the lab for testing.

A severe Salmonella infection will require more testing to see which specific germ is causing the illness and which antibiotics can be used to treat it.

How Are Salmonella Infections Treated?

If your child has salmonellosis and a healthy immune system, your doctor may let the infection pass without giving any medicines. But any time a child develops a fever, headache, or bloody diarrhea, call the doctor to rule out any other problems.

If your child is infected and has a fever, you may want to give acetaminophen to lower the temperature and relieve cramping. As with any infection that causes diarrhea, it's important to give your child plenty of liquids to avoid dehydration.

How Long Does a Salmonella Infection Last?

Salmonellosis symptoms can take from 6 to 72 hours to start after someone ingests the bacteria. In most people, the illness lasts for 4 to 7 days after symptoms begin.

Can Salmonella Infections Be Prevented?

Hand washing is a powerful way to guard against Salmonella infections. So teach kids to wash their hands well and often, particularly after trips to the bathroom and before handling food.

Here are some other ways to protect your family from Salmonella infections:

  • Cook food thoroughly. Salmonella bacteria are most commonly found in animal products and can be killed by the heat of cooking. Don't serve raw or undercooked eggs, poultry, or meat. Microwaving is not a reliable way to kill the bacteria. If you're pregnant, be especially careful to avoid undercooked foods.
  • Handle eggs carefully. Because Salmonella bacteria can contaminate even intact and disinfected grade A eggs, cook them well and avoid serving poached or sunny-side up eggs (with runny yolks).
  • Avoid foods that might contain raw ingredients. Caesar salad dressing, the Italian dessert tiramisu, homemade ice cream, chocolate mousse, eggnog, cookie dough, and frostings can contain raw eggs. Unpasteurized milk and juices also can be contaminated with Salmonella.
  • Clean cooking surfaces regularly. Keep uncooked meats away from cooked and ready-to-eat foods. Thoroughly wash your hands, cutting boards, counters, and knives after handling uncooked foods.
  • Take care with pets. Avoid contact with the feces of family pets — especially reptiles. Wash your hands well after handling an animal and make sure that no reptiles are permitted to come into contact with a baby. Even healthy reptiles (especially turtles and iguanas) are not safe pets for small children and should not be in the same house as an infant.
  • Don't cook food for others if you are sick, especially if you have vomiting or diarrhea.
  • Keep food chilled. Don't leave cooked food out for more than 2 hours after serving (1 hour on a hot day) and store it promptly. Also, keep your refrigerator set to under 40°F (4.4°C).
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Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2020 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.

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