Gastroenteritis

Gastroenteritis and food poisoning are common clinical problems that can present with similar symptoms, including diarrhea, vomiting, abdominal pain, and nausea. The following organisms are implicated

Viruses

  1. Norovirus: The most common cause of viral gastroenteritis in adults and children. Highly contagious and often responsible for outbreaks in community settings like schools, cruise ships, and nursing homes.
  2. Rotavirus: A leading cause of gastroenteritis in infants and young children globally. Vaccination has reduced its incidence in many countries.
  3. Adenovirus: Can cause gastroenteritis, especially in children.
  4. Astrovirus: Another cause of gastroenteritis, primarily affecting infants, young children, and the elderly.

Bacteria

  1. Campylobacter: Commonly associated with poultry, unpasteurized milk, and contaminated water.
  2. Salmonella: Associated with undercooked eggs, poultry, and meat, and contaminated produce.
  3. Shigella: Typically spread through person-to-person contact or contaminated food and water. Common in young children.
  4. Escherichia coli (E. coli): Certain strains (like E. coli O157:H7) cause gastroenteritis. Associated with undercooked ground beef, unpasteurized milk and juice, and contaminated water.
  5. Clostridium difficile (C. diff): Associated with antibiotic use and healthcare settings.
  6. Clostridium botulinum: Produces botulinum toxin
  7. Vibrio cholerae: Causes cholera, associated with contaminated water, especially in areas with poor sanitation.
  8. Staphylococcus aureus: Can produce toxins causing food poisoning, often linked to improperly stored or handled food.
  9. Bacillus cereus: Another cause of food poisoning, often associated with rice and reheated food.

Parasites

  1. Giardia lamblia: A common cause of waterborne gastroenteritis. Associated with streams, lakes, and pools, as well as person-to-person contact in childcare settings.
  2. Cryptosporidium: Also waterborne, causes prolonged diarrhea, particularly in immunocompromised individuals.
  3. Entamoeba histolytica: Causes amoebiasis, associated with poor sanitation and contaminated water.

Diagnosis

Gastroenteritis

  1. Clinical Presentation: Acute onset of diarrhea, nausea, vomiting, abdominal pain, and sometimes fever.
  2. History: Recent consumption of contaminated food or water, travel history, exposure to others with similar symptoms.
  3. Physical Examination: Assess for HR, BP, hydration and abdominal tenderness.
  4. Laboratory Tests: Often unnecessary in mild cases. Stool cultures, PCR, or antigen testing if bacterial or parasitic infection is suspected, particularly in severe cases.

Food Poisoning

  1. Clinical Presentation: Similar to gastroenteritis but often includes more pronounced nausea and vomiting, and symptoms often start within hours of eating contaminated food.
  2. History: Ingestion of high-risk foods (e.g., undercooked meats, dairy products, shellfish), food from questionable sources.
  3. Physical Examination: Assess for HR, BP, hydration and abdominal tenderness.
  4. Laboratory Tests: Often unnecessary in mild cases. Stool culture, or testing for specific toxins (e.g., for suspected botulism) depending on the suspected source.

Differential Diagnosis

  1. Infectious Colitis: Like Shigella, Salmonella.
  2. Inflammatory Bowel Disease: Crohn’s disease, ulcerative colitis.
  3. Irritable Bowel Syndrome (IBS): Especially for recurrent symptoms.
  4. Pancreatitis: Especially if there is significant abdominal pain.
  5. Appendicitis: In cases with localized right lower quadrant pain.
  6. Biliary Tract Disease: Gallstones, cholecystitis.
  7. Medication Side Effects: Antibiotics, laxatives.
  8. Endocrine Disorders: Diabetic ketoacidosis, hyperthyroidism.

Management

Gastroenteritis

  1. Hydration: Oral rehydration solution (ORS) is key. IV fluids for severe dehydration or if unable to tolerate oral intake.
  2. Diet: Resume normal diet as tolerated, focusing on easily digestible foods.
  3. Symptom Management: Antidiarrheals (e.g., loperamide) may be used in adults but generally avoided in children and severe infections.
  4. Antibiotics: Not routinely used except in specific bacterial infections (e.g., Shigella, some Salmonella species) or severe cases.
    1. Azithromycin 1g oral stat (or for 3/7 is severe)

Food Poisoning

  1. Hydration and Diet: Similar to gastroenteritis.
  2. Identifying and Treating Specific Toxins: e.g., antitoxin for botulism.
  3. Antibiotics: Depending on the identified organism (e.g., Campylobacter, certain E. coli strains).
  4. Prevention Education: Safe food handling and preparation practices.

Follow-Up and Prevention

  • Monitoring: Most cases resolve without complications. Watch for signs of dehydration or worsening symptoms.
  • Prevention: Proper food handling, cooking, and storage. Hand hygiene.
  • Vaccination: Rotavirus vaccine for children.
  • Specialist Referral: Consider for severe or atypical cases, suspected non-infectious causes, or immunocompromised patients.
  • Public Health Notification: Required for certain pathogens to prevent outbreaks.