CDC estimates that Salmonella bacteria cause about 1.35 million infections, 26,500 hospitalizations, and 420 deaths in the United States every year.
Most people with Salmonella infection (or “salmonellosis”) develop diarrhea, fever, and abdominal cramps within 8 to 72 hours after exposure and recover within a few days to a week without specific treatment. However, some people—specifically, certain groups, including elderly or immunocompromised persons, infants and young children, and pregnant women—are more at risk for developing life-threatening complications from Salmonella infection.
Severe dehydration is one such complication. If a person infected with Salmonella does not drink enough to replace the fluid they are losing from diarrhea, they may become dehydrated. Warning signs of dehydration include irritability or confusion, fatigue, and dark-colored urine. If dehydration is severe, emergency room care or hospitalization may be needed so that fluids can be delivered intravenously.
Another dangerous complication is bacteremia, which affects approximately 5% of infected individuals. If the Salmonella bacteria enters a person’s bloodstream (bacteremia), it can infect tissues throughout the body. The bacteria can cause a focal infection, where it becomes localized in a tissue and causes an abscess, arthritis, endocarditis, or other severe illness.
Finally, a small number of persons with salmonellosis develop a complication called reactive arthritis. The terminology used to describe this type of complication has changed over time. The term “Reiter’s Syndrome” was used for many years but has now fallen into disfavor. The precise proportion of persons that develop reactive arthritis following a Salmonella infection is unknown, with estimates ranging from 2 to 15%. Symptoms of reactive arthritis include inflammation (swelling, redness, heat, and pain) of the joints, genitourinary tract (reproductive and urinary organs), or eyes.
More specifically, symptoms of reactive arthritis include pain and swelling in the knees, ankles, feet, and heels. Less frequently, the upper extremities may be affected, including the wrists, elbows, and fingers. Tendonitis (inflammation of the tendons) or enthesitis (inflammation where tendons attach to the bone) can occur. Other symptoms may include prostatitis, cervicitis, urethritis (inflammation of the prostate gland, cervix, or urethra), conjunctivitis (inflammation of the membrane lining the eyelid), or uveitis (inflammation of the inner eye). Ulcers and skin rashes are less common. Symptoms can range from mild to severe.