Salmonella risk factors: who is most at risk from salmonella

What Salmonella infection is

Salmonella are bacteria that can make people sick with an illness called salmonellosis. They live in the intestines of people and animals, and people get infected after swallowing the bacteria: by eating contaminated food, by drinking or having contact with contaminated water, or by touching animals, animal poop and the places animals live and roam (CDC).

CDC estimates that Salmonella cause about 1.35 million infections in the United States every year, and that contaminated food is the source for most of these illnesses. Salmonella are one of the leading causes of foodborne illness and the leading cause of hospitalizations and deaths linked to foodborne illness. CDC also estimates that only 1 in every 30 Salmonella infections is diagnosed, because most people with food poisoning do not see a doctor or give a sample for testing (CDC).

This page covers the types of Salmonella that cause diarrhea. Typhoid fever, a more serious disease caused by Salmonella, is not common in the United States but frequently occurs in developing countries (MedlinePlus).

Who is most at risk

CDC says anyone can get a Salmonella infection, but some groups have an increased chance of infection, and some people may become seriously ill. These groups are (CDC):

• Children younger than 5 years, and especially children younger than 1 year.
• Adults 50 years and older with underlying medical problems, such as heart disease.
• Adults 65 and older.
• People who have a weakened immune system.
• International travelers.

MedlinePlus says infection can be more serious in older adults, infants and people with chronic health problems, and that it can be serious if Salmonella gets into the bloodstream (MedlinePlus).

Common sources of infection

• Food. MedlinePlus says Salmonella occurs in raw poultry, eggs and beef, and sometimes on unwashed fruit and vegetables (MedlinePlus). CDC calls chicken a major source: more than 1 in every 25 packages of chicken at the grocery store is contaminated with Salmonella (CDC).
• Animals. You can also get infected after handling pets, especially reptiles such as snakes, turtles and lizards (MedlinePlus). CDC adds that healthy animals at petting zoos, farms, fairs, schools and daycares can carry Salmonella (CDC).
• Summer heat. Infection is more common in the summer, because warmer weather and unrefrigerated foods create ideal conditions for Salmonella to grow (CDC).
• Water and travel. In some parts of the world food and water safety standards might not be as high as in the United States, and you can get infected if you swallow water containing harmful germs while swimming (CDC).

Symptoms

Most people with Salmonella infection have watery diarrhea that might have blood or mucus, and stomach cramps that can be severe. Some also have headache, nausea, vomiting or loss of appetite. Symptoms usually start 6 hours to 6 days after infection and usually last 4 to 7 days (CDC). MedlinePlus also lists fever (MedlinePlus).

Signs of dehydration include little or no peeing, very dark pee, being very thirsty, a dry mouth or throat, feeling dizzy or lightheaded, and crying without tears (CDC).

Complications

CDC says Salmonella infection rarely leads to other health problems (CDC):

• Diarrhea that lasts for several months in some people.
• Infection that spreads beyond the intestines, for example to the blood (bacteremia), the membranes around the brain and spinal cord (meningitis), the bone (osteomyelitis) or a joint (septic arthritis). Some of these infections can have long-lasting effects. See our osteomyelitis risk factors and sepsis risk factors guides.
• Reactive arthritis, joint pain in a small number of people that can last for months or years and can lead to chronic arthritis. It is most common among people 15 to 35 years old.

CDC also notes that resistance to antibiotics is increasing in Salmonella, which can limit treatment options for people with severe infections (CDC).

Diagnosis and treatment

A health care provider diagnoses the infection with a stool test (MedlinePlus). CDC says most people recover without antibiotics; antibiotics are sometimes used for severe intestinal illness or for people at risk for severe illness. People with diarrhea should drink plenty of fluids, and children with diarrhea or vomiting can be given extra fluids such as oral rehydration salts. Talk to your healthcare provider before taking anti-diarrheal medicine, which might make the illness last longer; CDC says not to use it with bloody diarrhea, diarrhea and a fever, or diarrhea that has lasted more than 2 days (CDC).

Lowering your risk

CDC says everyone should take steps to prevent Salmonella infection, and that this is especially important if you are more likely to get infected or become seriously ill. Its tips (CDC):

• Keep your hands clean.
• Follow the four food safety steps: clean, separate, cook and chill.
• Play it safe around animals, including pets.
• When traveling abroad: "Boil it, cook it, peel it, or forget it!"
• Drink pasteurized milk and juices.
• Do not swallow water when swimming in pools, lakes or other bodies of water.

CDC also advises promptly refrigerating or freezing perishables, prepared foods and leftovers (CDC). If you are sick, wash your hands thoroughly after using the toilet, do not prepare food for others if possible, stay home from childcare, school and work, and be extra careful with hygiene for at least 2 weeks after diarrhea ends, because you can keep shedding Salmonella in poop (CDC).

For another foodborne germ that is especially risky in pregnancy, see our Listeria risk factors guide.

E. coli is another germ that spreads through contaminated food or water; CDC lists the same higher-risk groups of children younger than 5, adults 65 and older, people with weakened immune systems and international travelers (CDC). See our E. coli risk factors guide.

Common questions

How soon after eating does salmonella make you sick?

CDC says symptoms usually start 6 hours to 6 days after infection and usually last 4 to 7 days (CDC).

Do I need antibiotics?

Usually not. CDC says most people recover without antibiotics, which are sometimes used for severe illness or for people at risk of it (CDC).

Can I get salmonella from a pet?

Yes. MedlinePlus says you can get infected after handling pets, especially reptiles like snakes, turtles and lizards (MedlinePlus), and CDC says pets and other healthy animals can carry Salmonella (CDC).