GASTROENTERITIS

GASTROENTERITIS

 1. Introduction

Gastroenteritis is a medical condition characterized by inflammation of the gastrointestinal tract that involves both the stomach and the small intestine resulting in some combination of diarrhoea, vomiting, and abdominal pain and cramping.

Gastroenteritis is referred to as gastro, stomach bug, and stomach virus. It has also been called stomach flu and gastric flu.

Most cases in children are caused by rotaviruses.

In adults, noroviruses and Campylobacter are more common.

Less common causes include other bacteria (or their toxins) and parasites.

Transmission may occur due to consumption of improperly prepared foods or contaminated water or via close contact with individuals who are infectious.

2. Groups of pathogens that causes Gastroenteritis

a.      Rotavirus is the most common cause of severe diarrhoea among infants and young children.

b.      Noroviruses are the most common cause of viral gastroenteritis in humans . The viruses are transmitted by fecally-contaminated food or water; by person-to-person contact; and via aerosolization of the virus and subsequent contamination of surfaces

c.       Campylobacter is a genus of bacteria that are Gram-negative, spiral, and microaerophilic . The sites of tissue injury include the jejunum, the ileum, and the colon. Gastrointestinal perforation is a rare complication of ileal infection.

3.      3. Signs and Symptoms

Gastroenteritis typically involves both diarrhea and vomiting .

Abdominal cramping may also be present .

Signs and symptoms usually begin 12–72 hours after contracting the infectious agent.

Some viral causes may also be associated with fever, fatigue, headache, and muscle pain .

If the stool is bloody, the cause is less likely to be viral and more likely to be bacterial .

Dehydration is a common complication of diarrhea and a child with a significant degree of dehydration may have a prolonged capillary refill, poor skin turgor, and abnormal breathing.

 Repeat infections are typically seen in areas with poor sanitation, and malnutrition, stunted growth, and long-term cognitive delays can result .

Low grade fever (100 F)

Loss of appetite .

Loss of important electrolytes.

This may be signaled by little or no urine, extreme thirst, lack of tears, and dry mouth.

4. Causes

          1.Viral

a.      Rotavirus, norovirus, adenovirus, and astrovirus are known to cause viral gastroenteritis. Rotavirus is the most common cause of gastroenteritis in children. Rotavirus is a less common cause in adults due to acquired immunity.

b.      Norovirus is the leading cause of gastroenteritis among adults. Norovirus is the cause of about 10% of cases in children.

 2.Parasitic

c.       E. histolytica, is pathogenic; infection can can lead to amoebic dysentery or amoebic liver abscess.

d.      Giardia lives inside the intestines of infected humans or other animals. The Giardia parasite originates from contaminated items and surfaces that have been tainted by the feces of an infected animal.

e.      Cryptosporidium is the organism most commonly isolated in HIV-positive patients presenting with diarrhea and can cause gastrointestinal illness with diarrhea in humans.

3. Bacterial

    Campylobacter jejuni is the primary cause of bacterial gastroenteritis. Bacteria are the cause in about 15% of cases, with the most common types being Escherichia coli, Salmonella, Shigella, and Campylobacter species.

 Toxigenic Clostridium difficile is an important cause of diarrhea that occurs more often in the elderly.

“Traveler's diarrhea" is usually a type of bacterial gastroenteritis.

5.Transmission

Transmission may occur via consumption of contaminated water, or when people share personal objects.Bottle-feeding of babies with improperly sanitized bottles is a significant cause on a global scale.

Transmission rates are also related to poor hygiene, and in those with pre-existing poor nutritional status.

Some agents (such as Shigella) only occur in primates(a mammal of the order Primates, which contains prosimians and simians) , others may occur in a wide variety of animals

Diangnosis

Gastroenteritis is typically diagnosed clinically, based on a person's signs and symptoms.

Stool cultures should be performed in those with blood in the stool, those who might have been exposed to food poisoning, and those who have recently traveled to the developing world.

Diagnostic testing may also be done for surveillance. As hypoglycemia occurs in approximately 10% of infants and young children, measuring serum glucose in this population is recommended.

Electrolytes and kidney function should also be checked when there is a concern about severe dehydration.

6. Prevention Measures

Gastroenteritis is usually an acute and self-limiting disease that does not require medication. The preferred treatment in those with mild to moderate dehydration is oral rehydration therapy (ORT).

Metoclopramide and ondansetron, however, may be helpful in some children.

Butylscopolamine is useful in treating abdominal pain .

      Rehydration

The primary treatment of gastroenteritis in both children and adults is rehydration.

Drinks especially high in simple sugars, are not recommended in children under 5 years of age as they may increase diarrhea.

Plain water may be used if more specific and effective ORT preparations are unavailable .

A nasogastric tube can be used in young children to administer fluids if warranted.