digestive disorders
Overview of Gastroenteritis
Causes of Gastroenteritis
Themost commoncauses of gastroenteritis are Viruses (most common) Bacteria Parasites Other causes include Drug-Related Gastroenteritis and Chemical-Related Gastroenteritis None Drug-Related Gastroenteritis and Chemical-Related Gastroenteritis None Infectionsthat cause gastroenteritis can be transmitted from person to person, especially if people with diarrhea do not thoroughly wash their hands after a bowel movement. Infection also can occur if people touch their mouth after touching an object (such as a diaper or toy) contaminated by infected stool. All such transmission involving infected stool is termed fecal-oral transmission. A person, and sometimes large numbers of people (in which case an outbreak of illness is called an epidemic), can also become infected by eating food or drinking water that has been contaminated by infected stool. Most foods can be contaminated with bacteria and cause gastroenteritis if not cooked thoroughly or pasteurized. Contaminated water is sometimes ingested in unexpected ways, such as when swimming in a pond contaminated by stool from an animal or in a swimming pool contaminated by stool from another person. In some cases, gastroenteritis is acquired through direct contact with animals that carry the infectious microorganism. Overview of Viral Infections are the most common cause of gastroenteritis in the United States. Certain viruses infect cells in the lining of the small intestine where they multiply and cause watery diarrhea, vomiting, and fever. Four types of viruses cause gastroenteritis: norovirus, rotavirus, astrovirus, and enteric (intestinal) adenovirus. Most viral gastroenteritis infectionsare caused by Norovirus Gastroenteritis None Rotavirus Gastroenteritis None Astroviruscan infect people of all ages but usually infects infants and young children. In temperate climates, infection is most common during winter months. In tropical climates, infection is more common during summer months. It is spread by fecal-oral transmission. Symptoms start 3 to 4 days after infection. Adenovirusis the 4th most common cause of childhood viral gastroenteritis. It most commonly affects children under the age of 2. Infections occur year-round and increase slightly in the summer. The infection is spread by fecal-oral transmission and in respiratory droplets of moisture such as those produced by coughing. Anyone nearby may inhale these droplets and become infected. Symptoms start 3 to 10 days after infection. (such as Cytomegalovirus (CMV) Infection and Worldwide, about 1.6 million people die each year of gastroenteritis caused by an infection. Themost common bacterial causesof gastroenteritis are Campylobacter Infections None Overview of Clostridial Infections ( Escherichia coli Infections ( Salmonella Infections None Shigellosis None Staphylococcus aureus Infections , causing staphylococcal food poisoning Bacterial gastroenteritis is less common than viral gastroenteritis. Overview of Bacteria cause gastroenteritis by various means. Certain species, such as Cholera and Other bacteria (such as Staphylococcus aureus Infections [see also Some bacteria (such as certain strains of Escherichia coli Infections , SalmonellaandCampylobacterare common bacterial causes of diarrhea in the United States. Both infections are most frequently acquired from eating undercooked poultry. Unpasteurized milk is also a possible source.Campylobacteris occasionally transmitted by dogs or cats with diarrhea.Salmonellacan be transmitted by eating undercooked eggs and by having contact with reptiles (such as turtles or lizards), birds, or amphibians (such as frogs and salamanders). Species ofShigellaare also a common bacterial cause of diarrhea in the United States and are usually transmitted person to person (especially in day care centers), although foodborne outbreaks occur. E. coli Gastroenteritis can be caused by several different subtypes of the bacteria. ) is now probably the most common bacterial cause of diarrhea in the United States and is the most common cause of diarrhea that occurs after treatment with antibiotics (see Drug-Related Gastroenteritis and Chemical-Related Gastroenteritis ). However, it sometimes occurs in people who have not been treated with antibiotics. Antibiotics kill the healthy bacteria that normally reside in the intestines, which allows Several other bacteria cause gastroenteritis, but most are rare in the United States. Plague and Other Yersinia Infections can cause gastroenteritis or a syndrome that mimics appendicitis. A person is infected after ingesting undercooked pork, unpasteurized milk, or contaminated water. Several The most common parasites are Giardiasis None Cryptosporidiosis None , stick to the lining of the intestine and cause nausea, vomiting, diarrhea, and a general sick feeling. The resulting infection, called Giardiasis , occurs in every region of the United States and throughout the world. If the infection becomes persistent (chronic), it may keep the body from absorbing nutrients (called , causes watery diarrhea that is sometimes accompanied by abdominal cramps, nausea, and vomiting. The resulting infection, called Cryptosporidiosis , is usually mild in otherwise healthy people, but it may be severe or even fatal in people with a weakened immune system. It is most commonly acquired by drinking contaminated water. Because it is resistant to usual concentrations of chlorine, this parasite is the most common cause of and a collection of organisms referred to as Microsporidiosis . 