According to the World Health Organization (WHO), salmonella bacteria are one of the most common causes of foodborne illness around the world. In the United States alone, 40,000 cases are reported to the Centers for Disease Control each year, although many more go unrecognized. Although salmonella infections usually cause mild, self-limited gastroenteritis (salmonellosis), in some cases long-term complications and side effects result.
Abnormal Bowel Habits
Salmonella bacteria secrete a substance called enterotoxin, which disrupts the lining of the bowel and causes diarrhea. Usually, this diarrhea resolves within four to seven days. However, some people report abnormal bowel movements for up to one year after infection.
Metastatic Infections
In rare cases, salmonella infections spread (metastasize) to other areas of the body. Typically, metastatic infections are characterized by slow bacterial growth and delayed (weeks to months) presentation of symptoms. 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. Metastatic infections are uncommon in healthy adults. They usually occur in people with other medical problems and are usually very difficult to treat.
Autoimmune Disease
Some people make a cell surface marker known as HLA-B27, which resembles salmonella bacteria. After salmonella exposure, the immune system makes antibodies to the bacteria and, unfortunately, a person's own cells. The result is an autoimmune disease cause Reiter's Syndrome, which produces chronic joint pain (arthritis), eye inflammation (conjunctivitis with or without iritis) and problems with urination (urethritis). In a 2001 study presented in the journal "Clinics in Infectious Disease," nearly one-third of people infected with salmonella enteridis, one of the most common salmonella species, subsequently developed arthritis that lasted up to six months. Also, nearly 50 percent reported recurrence within three years.
Pregnant Women and Infants
According to the WHO, pregnant women and infants are particularly vulnerable to salmonella poisoning. Pregnant women experience more severe symptoms and appear to be at higher risk of metastatic infections. Transplacental salmonella infections have been associated with miscarriage and neonatal sepsis, as described in a 2006 issue of "Obstetrics and Gynecology." Infants in developed countries usually survive sepsis with intensive medical care; however, permanent, severe developmental delay has been described.
References
- World Health Organization: Salmonella
- Clinics in Infectious Disease; Reactive Arthritis and Reiter's Syndrome Following an Outbreak of Gastroenteritis Caused by Salmonella Enteritidis; MS Dworkin, PC Shoemaker, MJ Goldoft, JM Kobayashi; October 1 2001
- Obstetrics and Gynecology; Alerting Pregnant Women to the Risk of Reptile-Associated Salmonellosis; AM Milstone; February 2006
