Salmonella Gastroenteritis (Salmonellosis)

How Salmonella spreads

Salmonella lives in the intestines of animals, especially poultry, and is shed in their feces. People are infected by:

• eating undercooked chicken, turkey, eggs or meat
• eating raw cookie dough, homemade mayonnaise or other foods with raw eggs
• eating contaminated fruit, vegetables, sprouts, nut butters, spices or flour
• drinking unpasteurized milk or untreated water
• cross-contamination in the kitchen, from cutting boards, knives and hands
• touching reptiles (turtles, lizards, snakes), amphibians, backyard poultry or pet food and treats, then touching the mouth
• contact with an infected person's stool, for example when changing diapers

About 1.35 million infections occur in the US each year, according to CDC estimates.

Symptoms

• diarrhea, which may contain blood or mucus
• fever and chills
• stomach cramps
• nausea and vomiting
• headache and muscle aches
• loss of appetite

Symptoms usually last 4 to 7 days. Bowel habits may not return to normal for several months.

Who is at higher risk of severe illness

• infants and children under 5
• adults over 65
• pregnant women (risk of infection spreading to the baby)
• people with weakened immune systems: HIV, chemotherapy, organ transplant, steroid or biologic treatment
• people with sickle cell disease, who are at risk of bone infection (osteomyelitis)
• people taking acid-reducing medicines, which lower stomach acid protection
• people with artery grafts, aneurysms, heart valve disease or joint replacements, where bacteria in the blood can settle

Complications

• dehydration and kidney injury
• bloodstream infection (bacteremia) in about 5% of cases, which can spread to bones, joints, blood vessels, heart valves or the brain lining
• reactive arthritis: joint pain and swelling, eye inflammation and painful urination weeks after infection
• post-infectious irritable bowel syndrome
• chronic carriage: a small number of people shed bacteria for months

Nontyphoidal Salmonella is different from Salmonella Typhi, which causes typhoid fever, a systemic illness linked to travel.

Diagnosis

Most mild cases do not need testing. A stool test (culture or PCR) is done for severe illness, bloody diarrhea, high fever, symptoms lasting more than a week, high-risk people, or during outbreaks. Blood cultures are taken if bloodstream infection is suspected. Positive results are reported to public health authorities to track outbreaks.

Treatment

Fluids and rest

• drink small, frequent sips of water and oral rehydration solution
• for children, use oral rehydration solution and continue breastfeeding or normal feeding
• eat normal foods as tolerated
• anti-diarrheal medicines such as loperamide may be used briefly by adults without fever or bloody diarrhea, following the label. They are not recommended for children or for bloody diarrhea
• avoid alcohol, caffeine and very sugary drinks

Antibiotics

Antibiotics are not recommended for healthy people with mild illness, because they do not shorten symptoms much and can prolong shedding of bacteria. They are used for:

• severe illness or bloodstream infection
• infants under 3 months
• adults over 50 with heart valve or blood vessel disease, people over 65
• people with weakened immune systems or sickle cell disease

Antibiotic resistance is increasing, so choices are guided by testing.

Hospital care

IV fluids are needed for severe dehydration, and IV antibiotics for invasive infection.

Preventing salmonella

• cook poultry to 165 °F (74 °C), ground meat to 160 °F (71 °C) and eggs until yolks and whites are firm
• do not eat raw dough or batter
• wash hands with soap after using the bathroom, changing diapers and touching animals
• use separate cutting boards for raw meat and produce
• refrigerate perishable foods within 2 hours
• keep reptiles and backyard poultry out of kitchens, and do not let children under 5 handle them
• do not prepare food for others while you have diarrhea

Frequently asked questions

What are the symptoms of salmonella?

Common symptoms are diarrhea, fever, stomach cramps, nausea, vomiting and headache, starting 6 hours to 6 days after exposure. Diarrhea may be bloody. Most people recover in 4 to 7 days without treatment.

How long does salmonella last?

Symptoms usually last 4 to 7 days. Bowel habits may take weeks or months to return fully to normal. People can shed the bacteria in their stool for several weeks after recovery, so careful handwashing is important.

How do you get salmonella?

Most infections come from undercooked poultry, eggs or meat, contaminated produce, unpasteurized milk, or cross-contamination in the kitchen. Touching reptiles, backyard chickens or pet food and then the mouth is another common source, especially for children.

Do you need antibiotics for salmonella?

Usually not. Healthy people with mild illness recover with fluids and rest, and antibiotics can prolong carriage. Antibiotics are given to babies, older adults, people with weakened immune systems, and anyone with severe illness or bloodstream infection.

When should I see a doctor for salmonella?

See a doctor for fever above 39 °C (102 °F), bloody diarrhea, diarrhea lasting more than 3 days, vomiting that prevents drinking, or signs of dehydration. People at higher risk, such as babies, older adults and pregnant women, should seek care earlier.