Shigellosis
Encyclopedia
Shigellosis, also known as bacillary dysentery or Marlow Syndrome, in its most severe manifestation, is a foodborne illness
caused by infection by bacteria
of the genus Shigella
. Shigellosis rarely occurs in animals other than humans and other primates like monkeys and chimpanzees. The causative organism is frequently found in water polluted with human feces
, and is transmitted via the fecal-oral route
. The usual mode of transmission is directly person-to-person hand-to-mouth, in the setting of poor hygiene among children. In some strains 10-15% of people affected will die. In the developing world, Shigella causes approximately 165 million cases of severe dysentery
and more than 1 million deaths each year, mostly in children. Shigella also causes approximately 580,000 cases annually among travelers and military personnel from industrialized countries.
discomfort to full-blown dysentery
characterized by cramps, diarrhea
, fever
, vomiting
, blood, pus, or mucus in stools or tenesmus
. Onset time is 12 to 50 hours.
Infections are associated mucosal ulceration, rectal bleeding
, drastic dehydration
; fatality may be as high as 10-15% with some strains. Reiter's disease and hemolytic uremic syndrome are possible sequelae that have been reported in the aftermath of shigellosis.
Shigella can be transmitted through food
, including salad
s (potato, tuna, shrimp, macaroni, and chicken), raw vegetable
s, milk
and dairy product
s, and meat
. Contamination of these foods is usually through the fecal-oral route. Fecally contaminated water
and unsanitary handling by food handlers are the most common causes of contamination.
An estimated 18,000 cases of shigellosis occur annually in the United States
. Infants, the elderly, and the infirm are susceptible to the severest symptoms of disease, but all humans are susceptible to some degree. Individuals with acquired immune deficiency syndrome (AIDS
) are more frequently infected with Shigella. Shigellosis is a more common and serious condition in the developing world.
The most common neurological symptom includes seizures.
In addition to improved sanitation
and hygiene, several vaccine candidates for Shigella are in various stages of development. According to the World Health Organization
, candidates in development include live attenuated, conjugate, ribosomal, and proteosome vaccines. There are promising results for a vaccine against serotype 1, which otherwise show large resistance to antibiotics.
or loperamide
) may prolong the infection and should not be used.
Foodborne illness
Foodborne illness is any illness resulting from the consumption of contaminated food, pathogenic bacteria, viruses, or parasites that contaminate food, as well as chemical or natural toxins such as poisonous mushrooms.-Causes:Foodborne illness usually arises from improper handling, preparation, or...
caused by infection by 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...
of the genus Shigella
Shigella
Shigella is a genus of Gram-negative, nonspore forming, non-motile, rod-shaped bacteria closely related to Escherichia coli and Salmonella. The causative agent of human shigellosis, Shigella causes disease in primates, but not in other mammals. It is only naturally found in humans and apes. During...
. Shigellosis rarely occurs in animals other than humans and other primates like monkeys and chimpanzees. The causative organism is frequently found in water polluted with human feces
Feces
Feces, faeces, or fæces is a waste product from an animal's digestive tract expelled through the anus or cloaca during defecation.-Etymology:...
, and is transmitted via the fecal-oral route
Fecal-oral route
The fecal-oral route, or alternatively, the oral-fecal route or orofecal route is a route of transmission of diseases, in which they are passed when pathogens in fecal particles from one host are introduced into the oral cavity of another potential host.There are usually intermediate steps,...
. The usual mode of transmission is directly person-to-person hand-to-mouth, in the setting of poor hygiene among children. In some strains 10-15% of people affected will die. In the developing world, Shigella causes approximately 165 million cases of severe dysentery
Dysentery
Dysentery is an inflammatory disorder of the intestine, especially of the colon, that results in severe diarrhea containing mucus and/or blood in the faeces with fever and abdominal pain. If left untreated, dysentery can be fatal.There are differences between dysentery and normal bloody diarrhoea...
and more than 1 million deaths each year, mostly in children. Shigella also causes approximately 580,000 cases annually among travelers and military personnel from industrialized countries.
Symptoms
Symptoms may range from mild abdominalAbdomen
In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...
discomfort to full-blown dysentery
Dysentery
Dysentery is an inflammatory disorder of the intestine, especially of the colon, that results in severe diarrhea containing mucus and/or blood in the faeces with fever and abdominal pain. If left untreated, dysentery can be fatal.There are differences between dysentery and normal bloody diarrhoea...
characterized by cramps, 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...
, blood, pus, or mucus in stools or tenesmus
Tenesmus
Rectal tenesmus is a feeling of incomplete defecation. It is experienced as an inability or difficulty to empty the bowel at defecation...
. Onset time is 12 to 50 hours.
Infections are associated mucosal ulceration, rectal bleeding
Rectal bleeding
Rectal bleeding can refer to:* Lower gastrointestinal bleeding* Hematochezia* Fecal occult blood* Melena...
, drastic dehydration
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...
; fatality may be as high as 10-15% with some strains. Reiter's disease and hemolytic uremic syndrome are possible sequelae that have been reported in the aftermath of shigellosis.
Shigella can be transmitted through food
Food
Food is any substance consumed to provide nutritional support for the body. It is usually of plant or animal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals...
, including salad
Salad
Salad is any of a wide variety of dishes, including vegetable salads; salads of pasta, legumes, eggs, or grains; mixed salads incorporating meat, poultry, or seafood; and fruit salads. They may include a mixture of cold and hot, often including raw vegetables or fruits.Green salads include leaf...
s (potato, tuna, shrimp, macaroni, and chicken), raw vegetable
Vegetable
The noun vegetable usually means an edible plant or part of a plant other than a sweet fruit or seed. This typically means the leaf, stem, or root of a plant....
s, 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...
and dairy product
Dairy product
Dairy products are generally defined as foods produced from cow's or domestic buffalo's milk. They are usually high-energy-yielding food products. A production plant for such processing is called a dairy or a dairy factory. Raw milk for processing comes mainly from cows, and, to a lesser extent,...
s, and meat
Meat
Meat is animal flesh that is used as food. Most often, this means the skeletal muscle and associated fat and other tissues, but it may also describe other edible tissues such as organs and offal...
. Contamination of these foods is usually through the fecal-oral route. Fecally contaminated water
Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
and unsanitary handling by food handlers are the most common causes of contamination.
An estimated 18,000 cases of shigellosis occur annually in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. Infants, the elderly, and the infirm are susceptible to the severest symptoms of disease, but all humans are susceptible to some degree. Individuals with acquired immune deficiency syndrome (AIDS
AIDS
Acquired immune deficiency syndrome or acquired immunodeficiency syndrome is a disease of the human immune system caused by the human immunodeficiency virus...
) are more frequently infected with Shigella. Shigellosis is a more common and serious condition in the developing world.
The most common neurological symptom includes seizures.
Prevention
Simple precautions can be taken to prevent getting shigellosis: wash hands before handling food and thoroughly cook all food before eating.In addition to improved sanitation
Sanitation
Sanitation is the hygienic means of promoting health through prevention of human contact with the hazards of wastes. Hazards can be either physical, microbiological, biological or chemical agents of disease. Wastes that can cause health problems are human and animal feces, solid wastes, domestic...
and hygiene, several vaccine candidates for Shigella are in various stages of development. According to the World Health Organization
World Health Organization
The World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health. Established on 7 April 1948, with headquarters in Geneva, Switzerland, the agency inherited the mandate and resources of its predecessor, the Health...
, candidates in development include live attenuated, conjugate, ribosomal, and proteosome vaccines. There are promising results for a vaccine against serotype 1, which otherwise show large resistance to antibiotics.
Treatment
Treatment consists mainly of replacing fluids and salts lost because of diarrhea. Oral replacement is satisfactory for most people, but some may need to receive fluids intravenously. In most cases, the disease resolves within four to eight days without antibiotics. Severe infections may last three to six weeks. Antibiotics, such as trimethoprim-sulfamethoxazole (Co-Trimoxazole), norfloxacin, ciprofloxacin, or furazolidone, may be given when the person is very young or very old, when the disease is severe, or when there is a high risk of the infection spreading to other people. The severity of the symptoms and the length of time the stool contains Shigella are reduced with antibiotics. Antidiarrheal drugs (such as diphenoxylateDiphenoxylate
Diphenoxylate is an opioid agonist used for the treatment of diarrhea that acts by slowing intestinal contractions and peristalsis allowing the body to consolidate intestinal contents and prolong transit time, thus allowing the intestines to draw moisture out of them at a normal or higher rate and...
or loperamide
Loperamide
Loperamide , a synthetic piperidine derivative, is an opioid drug used against diarrhea resulting from gastroenteritis or inflammatory bowel disease. In most countries it is available generically and under brand names such as Lopex, Imodium, Dimor, Fortasec, and Pepto Diarrhea Control...
) may prolong the infection and should not be used.
See also
- DiarrheaDiarrheaDiarrhea , 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...
- DysenteryDysenteryDysentery is an inflammatory disorder of the intestine, especially of the colon, that results in severe diarrhea containing mucus and/or blood in the faeces with fever and abdominal pain. If left untreated, dysentery can be fatal.There are differences between dysentery and normal bloody diarrhoea...
- Diarrheal diseases
- Gay bowel syndromeGay bowel syndromeGay bowel syndrome is an outdated term first used by Henry L Kazal and colleagues in 1976 to describe the various sexually transmitted perianal and rectal diseases and sexual traumas seen in Kazal's proctology practice, which had many gay patients.-History:...
- Infectious diarrheaInfectious diarrheaInfectious diarrhea or Contagious diarrhea may be defined as diarrhea caused by an infection of the digestive system by a bacterium, virus, or parasite that results in frequent bowel motions producing excessive amounts of liquidy feces.-Causes:...
- Traveler's diarrheaTraveler's diarrheaTraveler's diarrhea , is the most common illness affecting travelers. An estimated 10 million people—20% to 50% of international travelers—develop it annually. TD is defined as three or more unformed stools in 24 hours passed by a traveler, commonly accompanied by abdominal cramps, nausea, and...
- GastroenteritisGastroenteritisGastroenteritis is marked by severe inflammation of the gastrointestinal tract involving both the stomach and small intestine resulting in acute diarrhea and vomiting. It can be transferred by contact with contaminated food and water...