Gastroenteritis: Definition, Causes, and Management
Gastroenteritis is an inflammation of the stomach and intestines characterized by diarrhea, vomiting, abdominal pain, and sometimes fever, primarily caused by viral, bacterial, or parasitic infections. 1
Etiology
Viral Causes (Most Common)
- Norovirus: A frequent cause during cold seasons, requiring only 10-100 viral particles for infection, with an incubation period of 12-48 hours followed by vomiting, diarrhea, abdominal pain, myalgia, and low fever 1
- Rotavirus: Commonly affects children, with an incubation period of 1-3 days followed by diarrhea, vomiting, and fever lasting 4-7 days 1
- Adenovirus (serotypes 40 and 41): Contributes to 5-20% of hospitalizations for childhood diarrhea in developed countries 1
- Astrovirus: More commonly affects children in institutional settings 1
- Cytomegalovirus (CMV): Particularly significant in immunocompromised patients 1, 2
Bacterial Causes
- Salmonella species: Require antibiotic treatment, especially in immunocompromised patients 1
- Shigella species: May cause bloody diarrhea 1
- Campylobacter species: Common bacterial cause with high fluoroquinolone resistance rate 1
- Yersinia species: Less common but can cause severe infection 1
- Clostridioides difficile: Increasing prevalence in both adults and children, especially after antibiotic exposure 1, 3
Clinical Presentation
Symptoms
- Diarrhea (watery, typically non-bloody) 1
- Vomiting (often precedes diarrhea) 1
- Abdominal pain 1, 2
- Fever (up to one-third of patients have temperature >102°F/39°C) 1
- Myalgia and general malaise 1
Duration and Course
- Acute gastroenteritis: Symptoms lasting <7 days 1
- Prolonged diarrhea: Symptoms lasting 7-13 days 1
- Persistent diarrhea: Symptoms lasting 14-29 days 1
- Chronic diarrhea: Symptoms lasting ≥30 days 1
Transmission
- Fecal-oral route: Primary mode of transmission 1, 2
- Person-to-person contact: Common in institutional settings 1
- Contaminated food or water 1
- Respiratory droplets (possible for some viruses) 1
- Fomites (contaminated surfaces) 1
Risk Factors
- Age: Highest incidence in children <5 years; highest hospitalization and death rates in persons ≥65 years 1
- Immunocompromised status: Increased risk for severe and prolonged disease 1, 2
- Institutional settings: Nursing homes, cruise ships, day-care facilities, and hospitals 1
- Travel to developing countries: More than half of travelers experience traveler's diarrhea 3
Diagnosis
- Clinical diagnosis based on symptoms in mild cases 4
- Laboratory testing not routinely needed for mild viral gastroenteritis 4
- Stool testing indicated for:
- Diagnostic methods:
Management
Rehydration (Primary Treatment)
- Mild dehydration: Oral rehydration therapy with half-strength apple juice followed by child's preferred liquids 4
- Moderate dehydration: Oral rehydration solutions 4
- Severe dehydration: Intravenous fluids and hospitalization 4
Symptomatic Treatment
- Antiemetics: Ondansetron may be used to prevent vomiting and improve tolerance of oral rehydration 4
- Antimotility and antisecretory drugs: Can be used for symptom control in select cases 5
Antimicrobial Therapy
- Generally not indicated for viral gastroenteritis 1
- Indicated for:
Prevention
- Hand hygiene: Thorough handwashing 4
- Vaccination: Rotavirus vaccine has reduced infections by up to 90% in children 5
- Breastfeeding: Provides protective antibodies 4
- Safe food and water practices 1
- Contact precautions in healthcare and institutional settings 3
- Prudent use of antibiotics to prevent C. difficile infections 3