Salmonellosis
Encyclopedia
Salmonellosis is an infection
Infection
An infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...

 with Salmonella bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

. Most people infected with Salmonella develop diarrhea
Diarrhea
Diarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and...

, fever
Fever
Fever is a common medical sign characterized by an elevation of temperature above the normal range of due to an increase in the body temperature regulatory set-point. This increase in set-point triggers increased muscle tone and shivering.As a person's temperature increases, there is, in...

, vomiting
Vomiting
Vomiting is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose...

, and abdominal cramps
Abdominal pain
Abdominal pain can be one of the symptoms associated with transient disorders or serious disease. Making a definitive diagnosis of the cause of abdominal pain can be difficult, because many diseases can result in this symptom. Abdominal pain is a common problem...

 12 to 72 hours after infection. In most cases, the illness lasts four to seven days, and most people recover without treatment. However, in some cases the diarrhea may be so severe that the patient becomes dangerously dehydrated
Dehydration
In physiology and medicine, dehydration is defined as the excessive loss of body fluid. It is literally the removal of water from an object; however, in physiological terms, it entails a deficiency of fluid within an organism...

 and must be taken to a hospital
Hospital
A hospital is a health care institution providing patient treatment by specialized staff and equipment. Hospitals often, but not always, provide for inpatient care or longer-term patient stays....

. At the hospital, the patient may receive intravenous fluid
Intravenous therapy
Intravenous therapy or IV therapy is the infusion of liquid substances directly into a vein. The word intravenous simply means "within a vein". Therapies administered intravenously are often called specialty pharmaceuticals...

s to treat the dehydration, and may be given medication
Medication
A pharmaceutical drug, also referred to as medicine, medication or medicament, can be loosely defined as any chemical substance intended for use in the medical diagnosis, cure, treatment, or prevention of disease.- Classification :...

s to provide symptom
Symptom
A symptom is a departure from normal function or feeling which is noticed by a patient, indicating the presence of disease or abnormality...

atic relief, such as fever reduction. In severe cases, the Salmonella infection may spread from the intestine
Intestine
In human anatomy, the intestine is the segment of the alimentary canal extending from the pyloric sphincter of the stomach to the anus and, in humans and other mammals, consists of two segments, the small intestine and the large intestine...

s to the blood
Blood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....

 stream, and then to other body sites, and can cause death unless the person is treated promptly with antibiotic
Antibiotic
An antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...

s. The elderly, infants, and those with impaired immune system
Immune system
An immune system is a system of biological structures and processes within an organism that protects against disease by identifying and killing pathogens and tumor cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own...

s are more likely to develop severe illness. Some people afflicted with salmonellosis later experience reactive arthritis
Reactive arthritis
Reactive arthritis , is classified as an autoimmune condition that develops in response to an infection in another part of the body. Coming into contact with bacteria and developing an infection can trigger the disease. Reiter's syndrome has symptoms similar to various other conditions collectively...

, which can have long-lasting, disabling effects. There are different kinds of Salmonella, including S. bongori and S. enterica.

The type of Salmonella usually associated with infections in humans, nontyphoidal Salmonella, is usually contracted from sources such as:
  • Poultry
    Poultry
    Poultry are domesticated birds kept by humans for the purpose of producing eggs, meat, and/or feathers. These most typically are members of the superorder Galloanserae , especially the order Galliformes and the family Anatidae , commonly known as "waterfowl"...

    , pork
    Pork
    Pork is the culinary name for meat from the domestic pig , which is eaten in many countries. It is one of the most commonly consumed meats worldwide, with evidence of pig husbandry dating back to 5000 BC....

    , and beef
    Beef
    Beef is the culinary name for meat from bovines, especially domestic cattle. Beef can be harvested from cows, bulls, heifers or steers. It is one of the principal meats used in the cuisine of the Middle East , Australia, Argentina, Brazil, Europe and the United States, and is also important in...

    , if the meat is prepared incorrectly or is infected with the bacteria after preparation.
  • Infected eggs
    Egg (food)
    Eggs are laid by females of many different species, including birds, reptiles, amphibians, and fish, and have probably been eaten by mankind for millennia. Bird and reptile eggs consist of a protective eggshell, albumen , and vitellus , contained within various thin membranes...

    , egg products, and milk
    Milk
    Milk is a white liquid produced by the mammary glands of mammals. It is the primary source of nutrition for young mammals before they are able to digest other types of food. Early-lactation milk contains colostrum, which carries the mother's antibodies to the baby and can reduce the risk of many...

      when not prepared, handled, or refrigerated properly.
  • Reptile
    Reptile
    Reptiles are members of a class of air-breathing, ectothermic vertebrates which are characterized by laying shelled eggs , and having skin covered in scales and/or scutes. They are tetrapods, either having four limbs or being descended from four-limbed ancestors...

    s, such as turtle
    Turtle
    Turtles are reptiles of the order Testudines , characterised by a special bony or cartilaginous shell developed from their ribs that acts as a shield...

    s, lizard
    Lizard
    Lizards are a widespread group of squamate reptiles, with nearly 3800 species, ranging across all continents except Antarctica as well as most oceanic island chains...

    s, and snake
    Snake
    Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...

    s, which may carry the bacteria on their skin.
  • Tainted fruits and vegetables.


The typhoidal form of Salmonella can lead to typhoid fever
Typhoid fever
Typhoid fever, also known as Typhoid, is a common worldwide bacterial disease, transmitted by the ingestion of food or water contaminated with the feces of an infected person, which contain the bacterium Salmonella enterica, serovar Typhi...

. Typhoid fever is a life-threatening illness, and about 400 cases are reported each year in the United States, and 75% of these are acquired while traveling out of the country. It is carried only by humans and is usually contracted through direct contact with the fecal matter
Feces
Feces, faeces, or fæces is a waste product from an animal's digestive tract expelled through the anus or cloaca during defecation.-Etymology:...

 of an infected person. Typhoidal Salmonella is more commonly found in poorer countries and can affect as many as 21.5 million persons each year, where unsanitary conditions are more likely to occur.

Epidemiology

Both salmonellosis and the Salmonella genus of microorganisms derive their names from a modern Latin coining after Daniel E. Salmon (1850–1914), an American veterinary surgeon. He had help from Theobald Smith
Theobald Smith
Theobald Smith ForMemRS was a pioneering epidemiologist and pathologist and is widely-considered to be America's first internationally-significant medical research scientist.- Education :...

, and together they found the bacterium in pigs.

Symptoms

The bacterium induces responses in the animal it is infecting, and this is what typically causes the symptom
Symptom
A symptom is a departure from normal function or feeling which is noticed by a patient, indicating the presence of disease or abnormality...

s, rather than any direct toxin
Toxin
A toxin is a poisonous substance produced within living cells or organisms; man-made substances created by artificial processes are thus excluded...

 produced. Symptoms are usually gastrointestinal, including nausea
Nausea
Nausea , is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It often, but not always, precedes vomiting...

, vomiting
Vomiting
Vomiting is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose...

, abdominal cramps and bloody diarrhea
Diarrhea
Diarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and...

 with mucus
Mucus
In vertebrates, mucus is a slippery secretion produced by, and covering, mucous membranes. Mucous fluid is typically produced from mucous cells found in mucous glands. Mucous cells secrete products that are rich in glycoproteins and water. Mucous fluid may also originate from mixed glands, which...

. Headache
Headache
A headache or cephalalgia is pain anywhere in the region of the head or neck. It can be a symptom of a number of different conditions of the head and neck. The brain tissue itself is not sensitive to pain because it lacks pain receptors. Rather, the pain is caused by disturbance of the...

, fatigue
Fatigue (physical)
Fatigue is a state of awareness describing a range of afflictions, usually associated with physical and/or mental weakness, though varying from a general state of lethargy to a specific work-induced burning sensation within one's muscles...

 and rose spots
Rose spots
Rose spots are red macular lesions 2-4 millimeters in diameter occurring in patients suffering from enteric fever . These fevers occur following infection by Salmonella typhi and Salmonella paratyphi respectively...

 are also possible. These symptoms can be severe, especially in young children and the elderly. Symptoms last generally up to a week, and can appear 12 to 72 hours after ingesting the bacterium
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

.

After bacterial infections, reactive arthritis
Reactive arthritis
Reactive arthritis , is classified as an autoimmune condition that develops in response to an infection in another part of the body. Coming into contact with bacteria and developing an infection can trigger the disease. Reiter's syndrome has symptoms similar to various other conditions collectively...

 (Reiters syndrome) can develop. In sickle-cell anemia
Sickle-cell disease
Sickle-cell disease , or sickle-cell anaemia or drepanocytosis, is an autosomal recessive genetic blood disorder with overdominance, characterized by red blood cells that assume an abnormal, rigid, sickle shape. Sickling decreases the cells' flexibility and results in a risk of various...

, osteomyelitis
Osteomyelitis
Osteomyelitis simply means an infection of the bone or bone marrow...

 due to Salmonella infection is much more common than in the general population. Though salmonella infection is frequently the cause of osteomyelitis in sickle-cell anemia patients, it is not the most common cause. The most common cause of osteomyelitis remains due to Staphylococcus infection.

Pathogenesis

An infectious process can only begin after living salmonellae (not only their toxins) reach the gastrointestinal tract. Some of the microorganisms are killed in the stomach, while the surviving salmonellae enter the small intestine and multiply in tissues (localized form). By the end of the incubation period, the macro-organisms
are poisoned by endotoxins that are released from the dead salmonellae. The local response to the endotoxins is enteritis and gastrointestinal disorder. In the generalized form of the disease, salmonellae pass through
the lymphatic system of the intestine into the blood of the patients (typhoid form) and are carried to various organs (liver, spleen, kidneys) to form secondary foci (septic form). Endotoxins first of all act on the vascular and nervous apparatus. This is manifested by increased permeability and decreased tone of the vessels, upset thermal regulation, vomiting and diarrhea. In severe forms of the disease, enough liquid and electrolytes are lost to upset the water-salt metabolism, to decrease the circulating blood volume and arterial pressure, and to cause hypovolemic shock. Septic shock may develop. Shock of mixed character (with signs of both hypovolemic and septic shock) are more common in severe salmonellosis. Oliguria and azotemia develop in severe cases as a result of renal involvement due to hypoxia and toxemia.

Incidence

About 142,000 Americans are infected each year with Salmonella
Salmonella enterica enterica
Salmonella enterica enterica is a subspecies of Salmonella enterica, the rod shaped, flagellated, aerobic, Gram-negative bacterium. It is a member of the genus Salmonella. Many of the pathogenic serovars of the S...

 Enteritidis
Salmonella enterica enterica
Salmonella enterica enterica is a subspecies of Salmonella enterica, the rod shaped, flagellated, aerobic, Gram-negative bacterium. It is a member of the genus Salmonella. Many of the pathogenic serovars of the S...

 from chicken eggs, and about 30 die.

Up to 2005

The U.S. Government reported that as many as 20% of all chickens were contaminated with Salmonella in the late 1990s, and 16.3% were contaminated in 2005. In the mid to late 20th century, Salmonella enterica serovar Enteritidis was a common contaminant of eggs. This is much less common now with the advent of hygiene measures in egg production, and the vaccination of laying hens to prevent Salmonella colonization. Various Salmonella serovars (strains) also cause severe diseases in animals other than humans.

2006

In June 2006, the BBC
BBC
The British Broadcasting Corporation is a British public service broadcaster. Its headquarters is at Broadcasting House in the City of Westminster, London. It is the largest broadcaster in the world, with about 23,000 staff...

 reported that the Cadbury chocolate manufacturer withdrew a number of products when products contaminated with Salmonella resulted in up to 56 cases of salmonellosis. The causes had been traced to a leaking pipe at a Cadbury plant in Herefordshire
Herefordshire
Herefordshire is a historic and ceremonial county in the West Midlands region of England. For Eurostat purposes it is a NUTS 3 region and is one of three counties that comprise the "Herefordshire, Worcestershire and Gloucestershire" NUTS 2 region. It also forms a unitary district known as the...

 in January 2006, though the announcement was not made until June.

2007

In February 2007, the U.S. Food and Drug Administration (FDA) issued a warning to consumers not to eat certain jars of Peter Pan
Peter Pan (peanut butter)
Peter Pan is a brand of peanut butter produced by ConAgra Foods and named after the J.M. Barrie character. The product was introduced by Swift & Company in 1920 under the name "E. K. Pond". The product was renamed in 1928...

 or Great Value peanut butter, due to risk of contamination with S. Tennessee.http://www.fda.gov/bbs/topics/NEWS/2007/NEW01563.html

In March 2007, around 150 people were diagnosed with salmonellosis after eating tainted food at a governor's reception in Krasnoyarsk, Russia. Over 1,500 people attended the ball on March 1, and fell ill as a consequence of ingesting salmonella-tainted sandwiches.

About 150 people were sickened by salmonella-tainted chocolate cake produced by a major bakery chain in Singapore in December 2007.http://www.channelnewsasia.com/stories/singaporelocalnews/view/316110/1/.html

2008

From April 10, 2008 to July 8, 2008, the rare Saintpaul serotype of Salmonella Enteritidis caused at least 1017 cases of salmonellosis food poisoning in 41 states throughout the United States, the District of Columbia, and Canada. As of July 2008, the U.S. Food and Drug Administration suspected the contaminated food product was a common ingredient in fresh salsa, such as raw tomato, fresh jalapeño pepper, fresh serrano pepper, and fresh cilantro. It is the largest reported salmonellosis outbreak in the United States since 1985. New Mexico and Texas have been proportionally the hardest hit by far, with 49.7 and 16.1 reported cases per million, respectively. The greatest number of reported cases have occurred in Texas (384 reported cases), New Mexico (98), Illinois (100), and Arizona (49). There have been at least 203 reported hospitalizations linked to the outbreak, it has caused at least one death, and it may have been a contributing factor in at least one additional death. The CDC
Centers for Disease Control and Prevention
The Centers for Disease Control and Prevention are a United States federal agency under the Department of Health and Human Services headquartered in Druid Hills, unincorporated DeKalb County, Georgia, in Greater Atlanta...

 maintains "it is likely many more illnesses have occurred than those reported." If applying a previous CDC estimated ratio of unreported salmonellosis cases to reported cases (38.6:1), one would arrive at an estimated 40,273 illnesses from this outbreak.

As of 18 July 2008, the FDA removed raw tomatoes and cilantro as potential carriers; however, fresh jalapeño and serrano peppers still remain.

In December 2008 and January 2009, several Midwestern states, including Ohio (officially confirmed by state authorities), reported an outbreak of salmonellosis from Salmonella typhimurium that had sickened at least 50 people, due to contaminated dairy products like cheeses.

2009

On January 17, 2009, the FDA announced they had traced the source of an outbreak of Salmonella
Salmonella enterica enterica
Salmonella enterica enterica is a subspecies of Salmonella enterica, the rod shaped, flagellated, aerobic, Gram-negative bacterium. It is a member of the genus Salmonella. Many of the pathogenic serovars of the S...

 Typhimurium
Salmonella enterica enterica
Salmonella enterica enterica is a subspecies of Salmonella enterica, the rod shaped, flagellated, aerobic, Gram-negative bacterium. It is a member of the genus Salmonella. Many of the pathogenic serovars of the S...

 to a plant in Blakely, Georgia
Blakely, Georgia
Blakely is a town in Early County, Georgia. As of the 2010 census, the city had a population of 5,068. This town is the county seat of Early County.-Geography:Blakely is located at ....

, owned by Peanut Corporation of America
Peanut Corporation of America
Peanut Corporation of America was a peanut-processing business founded in 1977 and headquartered in Lynchburg, Virginia. The company was forced out of business after being found to be the source of a massive salmonella outbreak in the United States during 2008 and 2009.PCA operated processing...

 (PCA), and urged people to postpone eating commercially-prepared or manufactured peanut butter-containing products and institutionally-served peanut butter. Salmonella was reported to be found in 46 states in the United States in at least 3,862 peanut butter-based products, such as crackers, energy bars, and peanut butter cookies from at least 343 food companies. Dog treats were affected, as well. At least 691 people in more than 46 states became sick, and the Salmonella claimed at least nine lives as of March 25.

Peanut butter and peanut paste manufactured by PCA were distributed to hundreds of firms for use as an ingredient in thousands of different products, such as cookies, crackers, cereal, candy and ice cream, all of which were recalled. Some products were also sold directly to consumers in retail outlets, such as dollar stores.

On March 14, 2009, expressing his own personal concern for the safety of his children who enjoy peanut butter, President Obama announced the establishment of the Food Safety Working Group, "an inter-agency effort to help overhaul the oversight system."
The announcement came days after the FDA, also responding, released its first "guidance" on dealing with Salmonella contamination.

Four-Inch Regulation

The "Four-Inch Regulation" or "Four-Inch Law" is a colloquial name for a regulation issued by the U.S. Food and Drug Administration in 1975, restricting the sale of turtles with a carapace
Carapace
A carapace is a dorsal section of the exoskeleton or shell in a number of animal groups, including arthropods such as crustaceans and arachnids, as well as vertebrates such as turtles and tortoises. In turtles and tortoises, the underside is called the plastron.-Crustaceans:In crustaceans, the...

 length of less than four inches. Exceptions are provided for scientific and educational use, export, and private sale.

The regulation was promulgated, according to the FDA, "because of the public health impact of turtle-associated salmonellosis." There had been reported cases of young children placing small turtles in their mouths, which led to the size-based restriction.

Prevention

The FDA has published guidelines to help reduce the chance of food-borne salmonellosis. Food must be cooked to 68–72°C (145–160°F) and liquids such as soups or gravies must be boiled. Freezing kills some Salmonella, but it is not sufficient to reliably reduce Salmonella below infectious levels. While Salmonella is usually heat-sensitive, it does acquire heat resistance in high-fat environments such as peanut butter.

Antibodies and vaccine development

Salmonella antibodies were first found in Malawi
Malawi
The Republic of Malawi is a landlocked country in southeast Africa that was formerly known as Nyasaland. It is bordered by Zambia to the northwest, Tanzania to the northeast, and Mozambique on the east, south and west. The country is separated from Tanzania and Mozambique by Lake Malawi. Its size...

 children in research published in 2008. The Malawian researchers have identified an antibody that protects children against bacterial infections of the blood caused by Salmonella. A study at Queen Elizabeth Hospital in Blantyre
Blantyre, Malawi
Blantyre or Mandala is Malawi's centre of finance and commerce, the largest city with an estimated 732,518 inhabitants . It is sometimes referred to as the commercial capital of Malawi as opposed to the political capital, Lilongwe...

 found that children up to two years old develop antibodies that aid in killing the bacteria. This could lead to a possible Salmonella vaccine.

See also

  • 1984 Rajneeshee bioterror attack
    1984 Rajneeshee bioterror attack
    The 1984 Rajneeshee bioterror attack was the food poisoning of 751 individuals in The Dalles, Oregon, United States, through the deliberate contamination of salad bars at ten local restaurants with salmonella...

  • Typhoid fever
    Typhoid fever
    Typhoid fever, also known as Typhoid, is a common worldwide bacterial disease, transmitted by the ingestion of food or water contaminated with the feces of an infected person, which contain the bacterium Salmonella enterica, serovar Typhi...

  • List of foodborne illness outbreaks

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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