Definition
Salmonellosis refers to infections caused by bacteria of the genus Salmonella. The two main forms are enteropathogenic salmonellosis (food poisoning) and typhoid or paratyphoid fever, which are more severe systemic infections.

Pathogenesis
Infection is primarily transmitted through the consumption of contaminated food or water, such as raw or undercooked poultry, eggs, and dairy. The bacteria multiply in the intestine, causing inflammation. In some cases, they can enter the bloodstream, leading to severe systemic disease.

Diagnosis
Diagnosis is made by culturing stool, blood, or other body fluids to detect the bacteria. In more severe cases, additional tests may be needed to assess complications.

Treatment

  • Mild cases: Managed with hydration and supportive care, without the use of antibiotics.
  • Severe cases or typhoid fever: Treated with antibiotics (e.g., quinolones, third-generation cephalosporins) to address systemic infection.

Prevention: Avoiding consumption of contaminated food, practicing good hygiene, such as thorough handwashing and safe food storage.

Timely treatment reduces the risk of complications such as sepsis, abscesses, or chronic carrier states. Preventive measures, including vaccination for typhoid fever, are important in high-risk areas.

Key figures: Incubation is usually 6 hours to 3 days, and the illness lasts about 4 to 7 days, resolving without specific treatment. Antibiotics are not given in uncomplicated disease.

Other organisms enter the differential diagnosis, notably norovirus and, following antibiotic therapy, Clostridioides difficile. Fever and blood in the stool point towards a bacterial cause.

Key figures

  • Incubation: 6 hours to 3 days
  • Duration: about 4 to 7 days, resolving without specific treatment
  • Antibiotics are not given in uncomplicated disease
  • Fever and blood in stool favour a bacterial cause

Frequently asked questions

How long does salmonellosis last?

Symptoms typically start 6 hours to 3 days after exposure and the illness lasts about 4 to 7 days, resolving without specific treatment. Because incubation can extend to 3 days, the suspected meal is not necessarily the most recent one.

Are antibiotics needed?

As a rule no. In uncomplicated disease antibiotics do not meaningfully shorten the illness and may prolong shedding of the organism. They are reserved for infants, elderly and immunocompromised patients, and for severe disease or evidence of bloodstream spread. Rehydration is the mainstay.

How is it distinguished from norovirus?

Fever and the presence of blood or mucus in the stool favour a bacterial cause such as salmonella, whereas norovirus typically produces sudden intense vomiting and diarrhoea spreading rapidly among people sharing a space. Definitive distinction requires stool testing, which is not needed in every case.

Sources


Content last updated: September 2026 (14/09/2026).