Description

• Acute diarrhea is an abnormal increase in stool frequency (≥3 in 24 hours) for <14 days duration
• Acute viral diarrhea (50–70%):
  • Most common form; usually occurs for 1–3 days; self-limited
• Bacterial diarrhea (15–20%):
  • Develops 6–24 hours after infected food ingested
  • Suspect if simultaneous illness is present in others who have shared contaminated food
  • Suspect Clostridium difficile in patients with recent antibiotic use.
• Protozoal infections (10–15%):
  • Cause prolonged, watery diarrhea (travelers from areas with contaminated water supply)
  • Consider if diarrhea lasts >7 days
• Traveler’s diarrhea typically begins 3–7 days after arrival in foreign location; often quite acute.
• System(s) affected: Gastrointestinal; Endocrine/Metabolic

Epidemiology

• In developing countries, acute diarrhea is more common in children, whereas in developed countries it may be seen in people of all ages.
• Acute diarrhea accounts for >150,000 hospital admissions each year

• 5th leading cause of death worldwide
• Affects 11% of the general population
• In developing countries, often seen in children age <5 years
• Rotavirus and adenovirus common in children age <2 years

Risk Factors

• Travel to developing countries
• Immunocompromised host
• Antibiotic use
• Daycare attendance
• Nursing home residency
• Pregnancy (20-fold increase for Listeriosis)

General Prevention

• Frequent handwashing; proper hygiene
• Strict food handling
• Special care during foreign travel to avoid contaminated water and uncooked vegetables
• Avoid undercooked meats
• Probiotics may be used to help prevent traveler's diarrhea, although evidence is conflicting (1,2).
• Rotavirus vaccine for infants

Etiology

• Bacterial:
  • Escherichia coli
  • Salmonella
  • Shigella
  • Campylobacter jejuni
  • Vibrio parahaemolyticus
  • Vibrio cholerae
  • Yersinia enterocolitica
  • Clostridium difficile
  • Staphylococcus aureus
  • Bacillus cereus
  • Clostridium perfringens
  • Listeria monocytogenes
• Viral:
  • Rotavirus and norovirus (most common)
  • Adenovirus
  • Astrovirus
  • Cytomegalovirus (CMV) (HIV, immunocompromised)
• Protozoal:
  • Giardia lamblia
  • Entamoeba histolytica
  • Cryptosporidium
  • Isospora belli
  • Cyclospora
  • Microspora

Commonly Associated Conditions

• Inflammatory bowel disease
• Medications
• Ileal resection
• Gastrectomy
• Hyperthyroidism
• Diabetes mellitus
• Immunocompromise (HIV, malignancy, chemotherapy)