A Brief History of Salmonella
The term Salmonella refers to a family of bacteria known for more than 100 years to cause foodborne illness in humans. In 1885, a research assistant to veterinary surgeon Daniel Salmon discovered the first strain – Salmonella-Salmonella cholerasuis – and Dr. Salmon got the credit. Today, the number of known salmonella strains totals more than 2,300, and particular strains of Salmonella are now resistant to traditional antibiotics. Typically, none of the strains affects the taste, smell, or appearance of food. Strains that cause no symptoms in animals can sicken people, and vice versa.
The two most common strains in the U.S. are:
1) Salmonella serotype Enteritidis
2) Salmonella serotype Typhimurium
Some 62 percent of the S. Enteritidis outbreaks occurring from 1985 through 1999 were associated with food prepared at commercial food establishments. These included restaurants, caterers, delicatessens, bakeries, cafeterias, and markets.
Outbreaks can also be caused by a manufacturer of food. The largest recorded U.S. outbreak of salmonellosis, in 1985, involved S. Typhimurium, in milk from the Hillfarm Dairy in northern Illinois. Nearly 17,000 cases of poisoning were confirmed, and some 200,000 more cases were suspected within six Midwest states. Ominously, many thousands of people became seriously ill by drinking one of the most closely regulated products in the U.S. food supply. Two deaths were confirmed.
Where Does Salmonella Come From?
Salmonella is an enteric bacterium, which means that it lives in the intestinal tracts of humans and other animals, including birds. Birds and their close relatives, reptiles, are known to be frequent transmitters of Salmonella bacteria to humans. Frogs and other amphibians are also known to transmit the bacteria.
The most common source of Salmonella infection in humans comes from eating foods contaminated with animal feces. The manufacturer of the food, or improper food handling during preparation, usually causes the contamination of food. Contaminated foods usually look and smell normal. Although contaminated foods are often of animal origin, all foods, including vegetables, sauces, syrups, oils, and spices, may become contaminated. Because of the known danger salmonella presents, there are numerous safety measures and regulations required to be followed during the manufacture and preparation of food.
How Does Salmonella Spread and Attack the Body?
The salmonella bacterium attacks the body by stealth. The body cannot immediately detect salmonella infection. Salmonella has the uncanny abilities to hide inside intestinal-tract cells and then to disguise those cells as still-healthy cells.
As a result, the immune system’s antibodies are initially fooled. They do not fight the existing salmonella-laden cells. Salmonella does not show itself until its numbers swell by many multiples. At that point, the bacteria can typically defeat the body’s immune system. The salmonella bacterium achieves this disguise by injecting cells with proteins that mimic proteins of healthy cells. This ability was not known until 2008.
Symptoms, Treatment, and Long-Term Effects of Salmonella
The acute symptoms of Salmonella are sudden nausea, stomach cramps, bloody diarrhea with mucus, and fever.
Symptoms can start to occur as soon as a few hours after eating tainted food, but can also be delayed for as long as several days. The average incubation time for the bacteria is around 3 days.
The severity of symptoms for each infected individual will vary. The most likely to have severe symptoms are infants, the elderly, individuals already hospitalized, and the immune-suppressed.
Patients can become severely dehydrated due to diarrhea resulting from Salmonella. As a result, in some cases, an intravenous supply of fluids is necessary. From time to time, the infection has been known to spread from the intestines. When this happens, antibiotics are necessary – usually ampicillin, gentamicin, trimethoprim/sulfamethoxazole, or ciprofloxacin. Unfortunately, because feed animals are fed antibiotics, some Salmonella bacteria have become resistant to antibiotics.
The majority of cases salmonellosis resolve themselves in 6 days or less, without medical treatment, and cause no permanent harm. However, many cases of salmonella poisoning do not resolve until 10 days or more after symptoms arise, and require days of hospital treatment. Such serious and long-running cases of Salmonella have a notable likelihood of causing permanent damage. Our salmonella attorneys’ work with treating doctors has shown that some long-term complications can include the following:
Chronic Renal Dysfunction
Chronic renal dysfunction, or failure by kidneys to filter blood properly, is a possible complication of salmonella infection. In one study, chronic renal dysfunction was observed in 36 percent of patients infected by Salmonella. These included patients who recovered in a week or less and were not hospitalized.
Irritable-bowel syndrome is characterized by chronic abdominal pain, bloating, and changed bowel habits. After contracting salmonellosis, a person is more than 8 times as likely to develop irritable bowel syndrome. Persons with IBS tend to miss work, to be less productive when they do work, and to have less ability to recreate.
Some victims of salmonellosis develop Reiter’s Syndrome, consisting of pains in the joints, eye irritation, and painful urination. It can last for years and can lead to chronic, untreatable arthritis.
How Can I Prevent Salmonellosis?
To prevent salmonellosis, observe the following food safety practices:
- Do not eat or serve eggs that are raw or undercooked (some recipes call for raw eggs, such as for homemade hollandaise sauce or mayonnaise or ice cream, for Caesar salad dressings, for cookie dough, and for frostings).
- Cook foods until a meat thermometer says they have reached 165 degrees Fahrenheit, the killing temperature for Salmonella.
- Do not use raw or unpasteurized milk.
- Wash or peel fruits and vegetables before eating.
- Have separate cutting boards for meat and for vegetables, and wash them often and thoroughly.
- Use separate refrigerator shelves to store your raw meats well apart from your produce, cooked foods, and ready-to-eat foods.
- Wash your hands before handling any food, and between handling different food items.
- Wash your hands after contact with animal feces or with reptiles (reptiles are frequent carriers of salmonella bacteria).
- Place all foods known to carry Salmonella in the undercarriage of your shopping cart to prevent cross-contamination.