An Overview of Salmonella Disease

It's not just in eggs anymore

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What is Salmonella?

Salmonella are infectious bacteria associated with foodborne and gastrointestinal illnesses. The two main diseases caused by these bacteria are:

  1. Salmonellosis: Caused by Salmonella enteritidis or Salmonella typhimurium (actually a subtype of S. enteritidis), salmonellosis is a diarrheal disease, known more generically as gastroenteritis. Since it is associated with animals (rather than through contact with infected people), it is usually a foodborne disease, spread through consumption of contaminated foods, especially eggs, and poultry. It has also been reported in several large, nationwide outbreaks. A fair number of cases of transmission have also been attributed to exposure to pets infected with the microbe.
  1. Typhoid Fever: Typhoid fever is caused by Salmonella typhi. Also spread through ingestion of contaminated food or drink, this species is much less common, especially in industrialized countries, but is associated with more severe systemic illness. Although diarrhea can be a symptom of typhoid fever, it is absent in many cases. Transmission is often due to exposure to chronic carriers, including the infamous "Typhoid Mary".

What foods have been associated with Salmonella gastroenteritis outbreaks?

Salmonella outbreaks have occurred frequently with animal products, such as unpasteurized milk, dairy, eggs, poultry, and beef. However, since Salmonella is shed in animal feces, even vegetables and fruits are prone to contamination.

In addition, some household pets, especially reptiles (turtles, lizards, and snakes) and some birds, may carry the bacteria and spread the disease.

What are the symptoms of Salmonella foodborne (non-typhoid) infection?

Symptoms appear within approximately 8 to 72 hours after ingesting the contaminated food and may last 2 to 7 days.

They include:

  • Diarrhea (usually non-bloody)
  • Nausea
  • Vomiting
  • Abdominal pain
  • Headache
  • Fever

How can I avoid getting Salmonella gastroenteritis?

  • Avoid raw or undercooked eggs, poultry, or meat.
  • Drink only pasteurized milk and dairy products.
  • Thoroughly wash all fruits and vegetables, including those with inedible rinds or skins.
  • Practice good food preparation and dining habits.
  • Wash hands after handling animals and their feces.

I think I have Salmonella food poisoning. What should I do?

In most cases, Salmonella foodborne infections are self-limited and resolve within one week without the need for antibiotics. However, if you suspect you a Salmonella infection, contact your healthcare provider. Some individuals, particularly the young, the old, and the immunocompromised (having weakened immune systems), are more prone to severe disease. If you are part of the at-risk population, your doctor will likely ask for a stool sample to test for the presence of Salmonella and any other microbes that cause similar symptoms.

What treatments are available?

Infected individuals should drink lots of fluids to prevent dehydration. For patients at higher risk of severe infection, your doctor may prescribe antibiotics.

Is there a vaccine?

Currently, no vaccine is available for Salmonella enteritidis, the species responsible for most food-borne illnesses. There is, however, a vaccine for Salmonella typhi, the cause of typhoid fever, a more severe but less common disease in the United States. Individuals traveling to developing countries should contact their healthcare provider at least one week prior to travel to inquire about whether or not the vaccine is recommended.


Salmonella spp. USFDA Bad Bug Book. Center for Food Safety and Nutrition.

Salmonella. Centers for Disease Control and Prevention.

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