#Health Info: What is Salmonella Infection?

Salmonella infection, or salmonellosis, is a bacterial disease of the intestinal tract. Salmonella is a group of bacteria that cause typhoid fever, food poisoning, gastroenteritis, enteric fever and other illnesses. People become infected mostly through contaminated water or foods, especially meat, poultry and eggs. 

Salmonella is a gram-negative, rod-shaped bacilli that can cause diarrheal illness in humans. Put simply - Salmonella is a bacterium shaped like a rod with a cell wall composed of peptidoglycan.

Gram-negative is a term used in bacteriology for bacteria that lose the crystal violet stain and take the color of the red counterstain in Gram's method of staining. Gram-negative bacteria usually have a cell wall composed of a thin layer of peptidoglycan. Bacilli is the plural of bacillus. Bacteria that have a rod-like shape are called bacilli.

The Salmonella family includes over 2,300 serotypes of bacteria - they are microscopic one-celled organisms. Salmonella enteritidis and Salmonella typhimurium are responsible for over 50% of all human infections in the USA. Some Salmonella strains that exist in humans can make animals sick, and vice-versa. The bacteria live in the gut of infected humans and animals. What is salmonellosis? Salmonellosis is an infection caused by Salmonella. Approximately 1.4 million Americans are affected with salmonellosis every year, of which about 500 die, according to the CDC (Centers for Disease Control and Prevention). In 2004 US authorities announced that Salmonella was responsible for 42% of human bacterial infections, followed by Campylobacter 37%, Shigella 15%, E. coli O157:H7 2.6%.

According to the HPA (Health Protection Agency), in 2008 9,864 people were affected with salmonellosis in the UK. In most of Western Europe, in countries such as the UK, France, Germany, Scandinavia, Holland, Switzerland and Belgium, the incidence of salmonellosis is very much lower than in the USA. What causes Salmonella infections (salmonellosis)? Salmonella live in the intestines of birds, animals and humans. Most human infections are caused by eating food or drinking water that has been contaminated by feces (excrement).

Foods that are most commonly infected are:
Uncooked meat, seafood and poultry - contamination most commonly occurs during the slaughtering process. Harvesting seafoods in contaminated waters is also a common cause.

Uncooked eggs - the Salmonella are usually present in the eggs when laid if the chicken is infected. Raw eggs may be found in some types of mayonnaise and homemade sauces.

Fruits and vegetables - if fruit and vegetables have been watered or washed in contaminated water there is a much higher chance they will be contaminated. Some kitchen practices may contaminate fruits and vegetables - if the person preparing the food handles raw meat and then touches the fruit without washing his/her hands, for example.

Lack of hygiene - kitchen surfaces that are not kept clean, lack of handwashing procedures during food preparation, and lack of handwashing after going to the toilet or changing a baby's diapers, are common routes for contamination and infection. A person with contaminated hands can pass the infection on to other people by touching them, or touching surfaces which others then touch.

Pet reptiles or amphibians - most reptiles and amphibians carry Salmonella in their gut without becoming ill. They shed the bacteria in their droppings, which can quickly spread onto their skin and then anything they come into contact with, including cages, toys, clothes, furniture and household surfaces. The Health Protection Agency (UK) advises families not to keep reptiles if there are children under 5, pregnant women, very elderly people, and/or people with weaker immune systems in the household.


Information from Medical News Today.