According to the World Health Organization (WHO), salmonella bacteria are one of the most common causes of foodborne illness in the world. In the United States, 1.4 million infections result in more than 150,000 doctor visits, 15,000 hospitalizations, and 500 deaths each year. Although salmonella typically causes mild, self-limited gastrointestinal problems (salmonellosis), in some cases, the after-effects of salmonella poisoning are increasing in duration.
Alteration in Bowel Habits
"Salmonellosis" is the name for the mild, self-limited gastroenteritis which is classically associated with salmonella poisoning. Symptoms, including fever, stomach cramps, nausea, vomiting and diarrhea, typically appear within 12 to 72 hours of ingestion and resolve within 4 to 7 days. In some cases, it may take up to a year for bowel habits to return completely to normal.
Metastatic Infections
In rare cases, salmonella escapes the intestine to enter the bloodstream. Bloodstream infection can be fatal, producing long-term complications as salmonella spreads (metastasizes) from the bloodstream to infect other areas of the body. Examples of metastatic salmonella infections include infection of the heart valves and lining of the heart (endocarditis), the bone (osteomyelitis), the kidneys (pyelonephritis), brain abscess and more. These infections are slow-growing and take much longer than the typical 12 to 72 hours to appear. They rarely occur in healthy adults, but are much more common in people with compromised immune systems (AIDS, cancer, sickle cell anemia) or multiple medical problems.
Autoimmune Disease
After salmonella exposure, the immune system makes antibodies to combat the bacteria. Unfortunately, salmonella bacteria resemble a cell surface marker that is present in many people. The result is an autoimmune disease cause Reiter's syndrome which produces chronic joint pain (arthritis), eye irritation (conjunctivitis), and problems with urination (urethritis). In a 2001 study presented in the journal Clinics in Infectious Disease, nearly one-third of people who were infected with Salmonella enteridis developed arthritis, which persisted for up to 6 months. Nearly 50 percent of them reported a recurrence after the initial episode resolved.
Pregnant Women and Infants
Pregnant women and infants are particularly vulnerable to salmonella poisoning. In the May 2008 issue of Archives of Obstetrics and Gynecology, the authors described a case of second trimester miscarriage, 1 week after resolution of mild maternal salmonella infection. Pregnant women experience more severe symptoms and appear to be at higher risk of metastatic infections. Transplacental salmonella infections (salmonella that crosses through the placenta) have been associated with miscarriage and neonatal sepsis. Infants in developed countries usually survive sepsis with intensive medical care; however, permanent, severe developmental delay has been reported.
References
- World Health Organization: Salmonella
- Clinics in Infectious Disease. Reactive arthritis and Reiter's syndrome following an outbreak of gastroenteritis caused by Salmonella enteritidis. Dworkin MS, Shoemaker PC, Goldoft MJ, Kobayashi JM. October 1, 2001.
- Archives of Gynecology and Obstetrics. Salmonella Mississippi: a rare cause of second trimester miscarriage. Gyang A, Saunders M. May 2008.
