Also known as infectious diarrhea, is inflammation of the gastrointestinal tract—the stomach and small intestine, and colon.
Gastroenteritis is defined as vomiting or diarrhea due to inflammation of the small or large bowel.
Symptoms may include diarrhea, vomiting and abdominal pain, fever, lack of energy and dehydration.
Acute gastroenteritis usually lasts less than two weeks.
Frequency 2.4 billion cases per year, with about 1.3 million deaths globally.
Gastroenteritis is the main reason for 3.7 million visits to physicians a year in the United States.
It is is usually caused by viruses.
Bacteria, parasites, and fungus can also cause gastroenteritis.
Children and those in the developing world are affected the most.
In children, rotavirus is the most common cause of severe disease.
In adults, norovirus and Campylobacter are common causes.
The disease can be spread by eating improperly prepared food, drinking contaminated water or close contact with a person who is infected.
Prevention of infectious gastroenteritis includes hand washing with soap, drinking clean water, proper disposal of human waste and breastfeeding babies instead of using formula.
The rotavirus vaccine is recommended as a prevention for children.
Treatment involves providing essential fluids.
For mild or moderate cases, this can be achieved by drinking oral rehydration solution
Breastfeeding continuation is recommended.
For more severe cases of gastroenteritis intravenous fluids may be needed.
Fluids may be provided by a nasogastric tube.
Zinc supplementation is recommended in children.
Generally, for acute gastroenteritis antibiotics are not recommended except for young children with fever and bloody diarrhea.
Cases of acute gastroenteritis that result in symptoms usually begin 12–72 hours after contracting an infectious agent.
Viral gastroenteritis usually resolves within one week.
Some viral infections are associated with fever, fatigue, headache and myalgias.
The association with bloody stool, is less likely to be related to a viral illness and much more likely to be bacterial in origin.
Episodes of bacterial acute gastroenteritis may be associated with aabdominal pain, and may persist for a number of weeks.
Symptomatic children infected with rotavirus usually make a full recovery within three to eight days.
Hemolytic uremic syndrome (HUS) may occur due to infection with Shiga toxin-producing Escherichia coli or Shigella species.
Viruses, particularly rotavirus, and the bacteria Escherichia coli and Campylobacter species are the primary causes of gastroenteritis.
Non-infectious causes are seen occasionally with acute gastroenteritis.
Acute gastroenteritis risk of infection is higher in children due to their lack of immunity, that they are less likely to practice good hygiene habits.
Viral gastroenteritis causes include: rotavirus, norovirus, adenovirus, and astrovirus are known to cause viral gastroenteritis.
Rotavirus is the most common cause of gastroenteritis in children, and produces similar rates in both the developed and developing world.
Viruses cause about 70% of episodes of infectious diarrhea in the pediatric age group.
Rotavirus is less common cause of acute gastroenteritis adults due to acquired immunity.
Norovirus is the cause in about 18% of all cases of acute gastroenteritis, and is the leading cause of gastroenteritis among adults in America, causing greater than 90% of outbreaks.
Epidemics typically occur when groups of people spend time in close physical proximity to each other, such as on cruise ships, in hospitals, or in restaurants.
Patients with norovirus may remain infectious even after their diarrhea has ended.
Norovirus is the cause of about 10% of cases in children.
Campylobacter jejuni is the primary cause of bacterial gastroenteritis in the developed world with half of these cases associated with exposure to poultry.
In children, bacteria causes about 15% of cases of acute gastroenteritis, with the most common types being Escherichia coli, Salmonella, Shigella, and Campylobacter species.
Food contaminated with bacteria and remains at room temperature for several hours, the bacteria multiply and increase the risk of infection in those who consume the food.
Foods commonly associated with illness include: raw or undercooked meat, poultry, seafood, and eggs; raw sprouts; unpasteurized milk, soft cheeses; and fruit and vegetable juices.
Cholera is usually transmitted by contaminated water or food,and is common cause of gastroenteritis in the developing world, especially sub-Saharan Africa and Asia.
Toxigenic Clostridium difficile is an important cause of diarrhea that occurs more often in the elderly, and a common cause of diarrhea in those who are hospitalized and is frequently associated with antibiotic use.
Infants can carry Toxigenic Clostridium difficile, bacteria without developing symptoms.
Staphylococcus aureus infectious diarrhea may be a result of antibiotic usage.
Travelers diarrhea is usually a manifestation of a bacterial gastroenteritis.
Persistent form of travelers diarrhea is usually parasitic.
The risk of diarrhea is increased in the presence of acid-suppressing medications, following exposure to organisms such as Clostridium different seal, salmonella, and Campylobacter species.
The risk of gastroenteritis is greater in those taking proton pump inhibitors than with H2 antagonists.
Parasitic gastroenteritis is most common with Giardia lamblia but Entamoeba histolytica, Cryptosporidium spp., and other species have also been implicated.
Parasitic agents comprise about 10% of gastroenteritis cases in children.
Giardiasis occurs more commonly in the developing world.
Giardia gastroenteritis occurs more commonly in travelers to areas with high prevalence, in children attending day care facilities and in men who have sex with men.
Giardia gastroenteritis occurs at higher rate following disasters.
Transmission may occur from drinking contaminated water or when people share personal objects.
Water quality typically worsens during the rainy season.
Gastroenteritis outbreaks are more common during the rainy season.
In areas with four seasons, infections are more common in the winter.
Bottle-feeding of babies with improperly sanitized bottles is a significant cause of gastroenteritis.
Transmission rates are increased by poor hygiene, crowded households, and in individuals with poor nutritional status.
Non-infectious causes of inflammation of the gastrointestinal tract include: medications, lactose, gluten, Crohn’s disease, and some food-related conditions.
The changes in the small bowel are typically noninflammatory, while the ones in the large bowel are inflammatory.
The number of pathogens required to cause an infection varies from as few as one for Cryptosporidium to as many as 108 for Vibrio cholerae.
Diagnosis is typically clinical, based on a signs and symptoms.
Determining the cause of gastroenteritis usually does not alter management of the condition.
Stool cultures are performed in those with blood in the stool.
Stool cultures are also performed in those felt to be exposed to food poisoning, and those who have recently traveled to the developing world.
Stool cultures may also be appropriate in children younger than 5, old people, and those with poor immune function with gastroenteritis.
Dehydration from gastro typically divided into mild (3–5%), moderate (6–9%), and severe (≥10%) cases.
Hand washing with soap has been found to decrease rates of gastroenteritis in both the developing and developed world by as much as 30%.
Breastfeeding is important, especially in places with poor hygiene, as is improvement of hygiene generally.
Breast milk reduces both the frequency of infections and their duration.
Rotavirus vaccine be offered to all children globally.
Rotavirus vaccine may also prevent illness in non-vaccinated children by reducing the number of circulating infections, and has substantially decreased the number of cases of diarrhea by as much as 80 percent.
The first dose of vaccine should be given to infants between 6 and 15 weeks of age
The oral cholera vaccine is 50–60% effective over 2 years.
It is usually an acute and self-limiting process that does not require medication management.
The preferred treatment in those with mild to moderate dehydration is oral rehydration therapy (ORT).
For children with vomiting, anti vomiting medications may be helpful, and butylscopolamine is useful in treating abdominal pain.
Replacement therapy made from wheat or rice, which may be superior to those based on simple sugars, as drinks especially high in simple sugars, such as soft drinks and fruit juices, are not recommended in children under 5 years of age as they may increase diarrhea.
Some probiotics have been shown to be beneficial in reducing both the duration of illness and the frequency of stools.
Probiotics may also be useful in preventing and treating antibiotic associated diarrhea.
Fermented milk products are similarly beneficial for gastroenteritis.
Antiemetics may be helpful for treating vomiting.
Antibiotics are not usually used for gastroenteritis.
Antibiotics are considered if symptoms are particularly severe or a a susceptible bacterial cause is isolated.
Macrolides are preferred over a fluoroquinolone due to lower rates of resistance.
Pseudomembranous colitis, usually caused by antibiotics use, is usually managed by discontinuing the causative agent and treating it with either metronidazole or vancomycin.
The use of antibiotics in young children who have both bloody diarrhea and fever.
Antimotility agents are discouraged in people with bloody diarrhea or diarrhea that is complicated by fever.
Loperamide, an opioid analogue, is commonly used for the symptomatic treatment of diarrhea,
Bismuth subsalicylate, an insoluble complex of trivalent bismuth and salicylate, can be used in mild to moderate cases of diarrhea.
In 2011, in those less than five years, there were about 1.7 billion cases of gastroenteritis resulting in 0.7 million deaths, most of these occurring in the world’s poorest nations.
More than 450,000 of these fatalities are due to rotavirus in children under 5 years of age.
Cholera causes about three to five million cases of disease and kills approximately 100,000 people each year.
In the developing world, children less than two years of age frequently get six or more infections a year that result in significant gastroenteritis.
Gastroenteritis is less common in adults, partly due to the development of acquired immunity.
After the common cold, infections causing gastroenteritis are the second most common infection resulting in between 200 and 375 million cases of acute diarrhea and approximately 10,000 deaths annually.
Abut 150 to 300 of these deaths occur in children less than five years of age.