Is Salmonella Contagious: Transmission and Prevention


Salmonella causes about 1.3 million infections in the United States each year. It leads to an illness called salmonellosis and is one of the most common types of food poisoning.

This illness can cause fever and vomiting, as well as serious inflammation in the gastrointestinal tract. Some strains cause infection in the bones, blood, urine, joints, and the nervous system. It can also cause severe disease. Salmonella tends to be diagnosed more often in the summer than in the winter months.


How Salmonella Is Spread

Salmonella is a bacterium that can live in and cause infections in the intestines of animals and humans.

If a human has contact with food, water, animals, or objects that have been contaminated with bacteria from human or animal feces, they can contract and spread salmonella.

Consuming raw or undercooked food is another way salmonella is spread. When food is cooked at the recommended safe temperature, salmonella will be destroyed. If a person eats certain foods that are undercooked, however, they may be at risk. These foods include:

  • Seafood
  • Poultry
  • Raw eggs
  • Cookie dough containing raw eggs

Other factors include:

  • Improperly washing hands before food preparation
  • Preparing food on surfaces that have come into contact with raw meat contaminated with salmonella

Fruits and vegetables can also be contaminated by salmonella acquired through contaminated water and soil.

How Long You’re Contagious

When an individual eats food contaminated with salmonella, the length of illness and time that they are contagious depends on the individual. For some, it is days or weeks, while others can be long-term asymptomatic carriers. However, nontyphoidal salmonella is rarely spread from person to person.

Salmonella infections are contagious, and they can be dangerous if a person who has the infection is asymptomatic and spreads it unknowingly.

The bacteria can be passed from human to human through utensils such as spoons, forks, and straws, and by sharing cups and glasses.

Can Salmonella Live on Surfaces?

Salmonella can live on surfaces that are not cleaned properly. In fact, the bacteria are known to live on surfaces for up to four hours.

How to Know If You’re Sick

Salmonella typically makes a person sick for four to seven days.

People can start feeling symptoms from six hours to six days after contamination. There are more severe cases that can last longer and will need treatment in the hospital.

Some of the symptoms of salmonella are:

  • Upset stomach
  • Vomiting
  • Fever
  • Diarrhea
  • Abdominal pain

Diarrhea Warning

If diarrhea lasts long and is severe, it is important to get additional treatment as salmonella can spread into the bloodstream and to the organs. If this happens, hospitalization may be needed for treatment.

Individuals most at risk for severe salmonella are the following:

  • Infants
  • People who have an inflammatory bowel disease like Crohn’s disease or ulcerative colitis
  • Individuals who have weak immune systems
  • People who are 65 years and older
  • People who are pregnant

How to Prevent Salmonella

There are several ways that you can prevent salmonella.

If you are handling or preparing food, it is important to thoroughly wash your hands with soap and warm water before and afterward. It is also important to clean the countertops, cooking utensils, and cutting boards with soap and water or a disinfectant before and after use. This prevents cross-contamination, the unintentional passing of the bacteria to other surfaces.  

If you are preparing vegetables, wash them thoroughly and cut them on a clean surface with a clean knife. When cooking meat, fish, or poultry, cook it thoroughly—at least until the minimum internal temperature is reached—to avoid spreading any bacteria.

Some tips on food safety as it relates to salmonella include the following:

  • Store fresh meats in plastic bags to prevent blood from dripping onto other foods.
  • Avoid eating meat that is raw or undercooked.
  • Avoid eating raw eggs or unpasteurized dairy products or foods containing these products.
  • Wash hands frequently and thoroughly with soap and warm water before, during, and after food preparation.
  • Food that is prepared should be put in the refrigerator within 30 minutes after eating.

Safe Meat Temperatures

When cooking meats, it is important they reach the recommended temperatures for safety. The suggested minimum internal temperatures for the following meats are:

  • 145 F for roasts, steaks, ham, and chops
  • 145 F for fish
  • 160 F for ground meats
  • 165 F for all poultry, including ground

Another safety precaution is to be careful when touching or playing with animals. If you handle chicks or chickens, ducks, rodents, farm animals, frogs and toads, or reptiles that frequently carry salmonella, including turtles, iguanas, and snakes, wash your hands and clothes thoroughly and keep them away from your mouth.

It is important to take all precautions to avoid getting salmonella poisoning. If you experience any symptoms, contact your healthcare provider immediately so they can provide you with the help you need or answer your questions.

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