Header graphic for print
Marler Blog Providing Commentary on Food Poisoning Outbreaks & Litigation

Salmonella

salmonella_bacteria.gif

Image (c) Dennis Kunkel Microscopy, Inc.

Salmonella is one of the most common enteric (intestinal) infections in the United States. Salmonellosis (the disease caused by Salmonella) is the second most common foodborne illness after Campylobacter infection. It is estimated that 1.4 million cases of salmonellosis occur each year in the U.S.; 95% of those cases are foodborne-related. Approximately 220 of each 1000 cases result in hospitalization and eight of every 1000 cases result in death. About 500 to 1,000 or 31% of all food-related deaths are caused by Salmonella infections each year. Salmonellosis is more common in the warmer months of the year.

Salmonella infection occurs when the bacteria are ingested, typically from food derived from infected food-animals, but it can also occur by ingesting the feces of an infected animal or person. Food sources include raw or undercooked eggs/egg products, raw milk or raw milk products, contaminated water, meat and meat products, and poultry. Raw fruits and vegetables contaminated during slicing have been implicated in several foodborne outbreaks.

Symptoms of Salmonella infection

The acute symptoms of Salmonella gastroenteritis include the sudden onset of nausea, abdominal cramping, and bloody diarrhea with mucous. Fever is almost always present. Vomiting is less common than diarrhea. Headaches, myalgias (muscle pain), and arthralgias (joint pain) are often reported as well. The onset of symptoms usually occurs within 6 to 72 hours after the ingestion of the bacteria. The infectious dose is small, probably from 15 to 20 cells.

Reiter’s Syndrome, which includes and is sometimes referred to, as reactive arthritis is an uncommon, but debilitating, result of a Salmonella infection. The symptoms of Reiter’s Syndrome usually occur between one and three weeks after the infection. Reiter’s Syndrome is a disorder that causes at least two of three seemingly unrelated symptoms: reactive arthritis, conjunctivitis (eye irritation), and urinary tract infection. The arthritis associated with Reiter’s Syndrome typically affects the knees, ankles, and feet, causing pain and swelling. Wrists, fingers and other joints can be affected, though with less frequency. With Reiter’s Syndrome, the affected person commonly develops inflammation where the tendon attaches to the bone, a condition called enthesopathy. Some people also develop heel spurs, bony growths in the heel that cause chronic or long-lasting foot pain. Arthritis from Reiter’s Syndrome can also affect the joints of the back and cause spondylitis, inflammation of the vertebrae in the spinal column. The duration of reactive arthritis symptoms can vary greatly. Most of the literature suggests that the majority of affected persons recover within a year. The condition, can, however, be permanent.

Detection and treatment of Salmonella Infection

Salmonella bacteria are discovered in stool cultures. Although blood cultures are rarely positive, bacteremia (bacteria in the blood stream) does occur in 5% of adults with Salmonella gastroenteritis and can result in spread to the heart (endocarditis), spleen, bone (osteomyelitis), and joints (Reiter’s Syndrome or reactive arthritis). However, blood cultures are often not performed and in most cases the blood stream is not infected. In the stool, the laboratory is challenged to pick out Salmonella from many other similar bacteria that are normally present. In addition, many persons submit cultures after they have started antibiotics, which may make it even more difficult for a microbiology lab to grow Salmonella. So, the diagnosis of salmonellosis may be problematic and many mild cases are culture negative.

Salmonella infections usually resolve in five to seven days, and many times require no treatment, unless the affected person becomes severely dehydrated or the infection spreads from the intestines. Persons with severe diarrhea may require rehydration, often with intravenous fluids. Treatment with antibiotics is not usually necessary, unless the infection spreads from the intestines, or otherwise persists, in which case the infection can be treated with ampicillin, gentamicin, trimethoprim/sulfamethoxazole, or ciprofloxacin. Some Salmonella bacteria have become resistant to antibiotics, possibly as a result of the use of antibiotics to promote the growth of feed animals.

For those persons who develop Reiter’s Syndrome, symptomatic treatment with high doses of a nonsteroidal anti-inflammatory drug and steroid injections into affected joints can be helpful in reactive arthritis. For people with severe joint inflammation, injections of corticosteroids directly into the affected joint may reduce inflammation. A small percentage of patients with reactive arthritis have severe symptoms that cannot be controlled with these treatments, in which case medicine that suppresses the immune system, such as sulfasalazine or methotrexate, may be effective. Exercise, when introduced gradually, may help improve joint function. Topical corticosteroids can be applied directly on the skin lesions associated with reactive arthritis.

Preventing Salmonella Infection

To prevent salmonellosis, cook poultry, ground beef, and eggs thoroughly before eating. In order to insure that eggs do not contain viable Salmonella they must be cooked at least until the yoke is solid, and meat and poultry must reach 160∫F or greater throughout. Be particularly careful with foods prepared for infants, the elderly, and those with a compromised immune system.

Do not eat or drink foods containing raw eggs, such as homemade eggnog and hollandaise sauce. Avoid drinking raw (unpasteurized) milk or products made from raw milk.

Wash hands, kitchen work surfaces, and utensils with soap and water immediately after they have been in contact with foods of animal origin. Also, wash hands with soap after handling reptiles, amphibians or birds, or after contact with pet feces. Infants and immunocompromised persons should have no direct or indirect contact with such pets.

Salmonella Infection Complications

The following infections result in very few people, but the few who are diagnosed will suffer for the rest of their lives.

Irritable Bowel Syndrome (IBS)

A recently published study surveyed the extant scientific literature and noted that post-infectious irritable bowel syndrome (PI-IBS) is a common clinical phenomenon first described over five decades ago. The Walkerton Health Study further notes that:

Between 5% and 30% of patients who suffer an acute episode of infectious gastroenteritis develop chronic gastrointestinal symptoms despite clearance of the inciting pathogens.

In terms of its own data, the “study confirm[ed] a strong and significant relationship between acute enteric infection and subsequent IBS symptoms.” The WHS also identified risk factors for subsequent IBS, including: younger age; female sex; and four features of the acute enteric illness—diarrhea for > 7days, presence of blood in stools, abdominal cramps, and weight loss of at least ten pounds.

Irritable bowel syndrome (IBS) is a chronic disorder characterized by alternating bouts of constipation and diarrhea, both of which are generally accompanied by abdominal cramping and pain. In one recent study, over one-third of IBS sufferers had had IBS for more than ten years, with their symptoms remaining fairly constant over time. IBS sufferers typically experienced symptoms for an average of 8.1 days per month.

As would be expected from a chronic disorder, IBS sufferers required more time off work, spent more days in bed, and more often cut down on usual activities, when compared with non-IBS sufferers. And even when able to work, a significant majority (67%), felt less productive at work because of their symptoms. IBS symptoms also have a significantly deleterious impact on social well-being and daily social activities, such as undertaking a long drive, going to a restaurant, or taking a vacation. Finally, while a patient’s psychological state may influence the way in which he or she copes with illness, and responds to treatment, there is no evidence that supports the theory that psychological disturbances in facts cause IBS or its symptoms.

Reiter’s Syndrome

Several bacteria, including Salmonella, induce septic arthritis. The resulting joint pain and inflammation can resolve completely over time or permanent joint damage can occur. In a small number of persons, the joint inflammation is accompanied by conjunctivitis and uveitis, (inflammation of the eyes), and cystitis (painful urination). This triad of symptoms is called Reiter’s Syndrome. Reiter’s Syndrome is a special form of reactive arthritis, autoimmune disorder triggered by the Salmonella infection. It occurs in persons with a genetic predisposition and can last for a year or more. Antibiotic treatment does not make a difference in whether or not the person later develops arthritis.

The term reactive arthritis refers to an inflammation of one or more joints, following an infection localized at another site distant from the affected joints. The predominant site of the infection is the gastrointestinal tract. During outbreaks of Salmonella infections, reactive arthritis incidences from 1% to 15% have been reported.

References

Angulo FJ, Baker NL, Olsen SJ, Anderson A, Barrett TJ. (2004). Antimicrobal Use in Agriculture: Controlling the Transfer of Antimicrobal Resistance to Humans. Seminars in Pediatric Infectious Diseases. 15(2): 78-85.

Angulo FJ, Nargund VN, and Chiller TC. (2004). Evidence of an Association Between Use of Anti-microbial Agents in Food Animals and Anti-microbial Resistance Among Bacteria Isolated from Humans and the Human Health Consequences of Such Resistance J. Vet. Med. B Infect. Dis. Vet. Public Health. 51(8-9):374-9.

CDC. (2005, October 13). Salmonella: Technical Fact Sheet. Retrieved August 29, 2007 from Centers for Disease Control and prevention Web site, http://www.cdc.gov/ncidod/dbmd/diseaseinfo/salmonellosis_t.htm.

CDC. 2007. Salmonella Surveillance: Annual Summary, 2005. Atlanta, Georgia: US Department of Health and Human Services.

Glynn MK, Bopp C, Dewitt W, Dabney P, Mokhtar M, Angulo FJ. (1998). Emergence of multidrug-resistant Salmonella enterica serotype typhimurium DT104 infections in the United States. N Engl J Med 338:1333–1338.

Hill Gaston JS, Lillicrap MS. (2003). Arthritis associated with enteric infection. Best Practices & Research Clinical Rheumatology 17(2):219-239.

Inman RD, Johnston MEA, Hodge M, Falk J, and Helewa A. (1988). Postdysenteric Reactive Arthritis, A Clinical and Immunogenic Study following an Outbreak of Salmonellosis. Arthritis and Rheumatism 31:1377-1383.

Mayo Clinic. (2007, April 12). Salmonella. Retrieved August 29, 2007 from Mayo Clinic Web site, http://www.mayoclinic.com/health/salmonella/DS00926.

Mead PM, Slutsker L, Dietz V, McCaig LF, Bresee JS, Shapiro C, Griffin PM, and Tauxe RV. (1999). Food-related Illness and Death in the United States. Emerg. Infect. Dis. 5:607-625.

MMWR Recomm Rep. (2001). Diagnosis and management of foodborne illnesses: a primer for physicians. January 26, 2001 / 50 (RR-2):1-69. Atlanta, GA: Centers for Disease Control and Prevention.

MMWR Surveillance Summaries, Appendix B. (1996). Guidelines for confirmation of foodborne-disease outbreaks. October 25, 1996 / 45:(SS-5) 59-66. Atlanta, GA: Centers for Disease Control and Prevention.

MMWR Weekly. (1996). Guidelines for confirmation of foodborne-disease outbreaks. October 25, 1996 / 45(S-5): 58-66. Atlanta, GA: Centers for Disease Control and Prevention.

MMWR Weekly. (2001). Summary of Notifiable Diseases, United States, 1999. April 06, 2001 / 48(53):1-104. Atlanta, GA: Centers for Disease Control and Prevention.

MMWR Weekly. (2006). Preliminary FoodNet Data on the Incidence of Infection with Pathogens Transmitted Commonly Through Food – 10 States, United States, 2005. April 14, 2006 / 55(14);392-395. Atlanta, GA: Centers for Disease Control and Prevention.

Stevenson JE, White DG, Torpey III DJ, Craig AS, Smith KE, Park MM, Pascucilla MA, Anderson AD, and the NARMS Working Group. (2002). Enhanced Surveillance for Antimicrobial Resistance Among Enteric Bacteria: NARMS Retail Food Study. International Conference on Emerging Infectious Diseases. Atlanta, GA, March 2002.

Wallinga, D. (2002, October). Antimicrobial Use in Animal Feed: an Ecological and Public Health Problem. Minnesota Medicine. 85. Retrieved January 16, 2008, from http://www.mmaonline.net/publications/MNMed2002/October/Wallinga.html.

  • http://www.digestivecare.co.uk ibs symptom

    Hey, this is a very informative article you’ve got here!! I’m definitely going to bookmark it!
    By the way, I found a IBS related site that has similar kind of webmaster’s kind of stuff! If you get time, check it out.
    http://www.digestivecare.co.uk/Irritable-bowel-syndrome-treatment-ibs_320_320_.html

  • Janice Alston

    Hi. I am doing a research paper on Salmonella, E-Coli an Heppertia, an i need some pamphlets and pictures of each one if you have free pamphlets could you please mail me as many as possible ASAp. This would really be helpful for my presentation.
    Janice Alston
    2106 Randall Street
    Greensbor, NC 27401

  • dcampbell

    I ate at a fast food restraunt and after i started eating my chicken sandwich, i realised it was completely raw on the inside so raw it was bleeding i feel fine but can do anything about this

  • Corey

    “Salmonellosis (the disease caused by Salmonella) is the second most common foodborne illness after Campylobacter infection.” — First, this is confusing because the article on camplyobactor says the exact opposite… and both discount norovirus as being the number one cause of foodborne illness.
    @dcampbell
    First, hopefully you did not continue to eat the sandwich. Second, as long as it was a whole muscle product (not ground) such as a whole chicken breast, technically it can be raw on the inside and still be safe (similar to a rare steak) as long as the outside recieved a good enough heat treatment… but since the inside wasn’t cooked all the way, it is possible that the outside did not receive enough heat. I’m not a doctor so this is not medical advice, but in my opinion you should just wait and see, if you develop symptoms (you know what you’re looking for right? since you read this website) see your doctor immediately.

  • timothy savage

    please call 404-955-1532