Gastroenteritis

Background

• Rapid-onset diarrheal illness usually lasting less than 2 weeks

Clinical Manifestations

Species	Incubation	Duration	Risk Factors	Symptoms
Staphylococcus aureus	1-6 hours	≤24 hours	preformed toxin in unrefrigerated food	watery diarrhea, with prominent vomiting
Bacillus cereus	1-6 hours	24-48 hours	preformed toxin in unrefrigerated food	watery diarrhea, with prominent vomiting
Clostridium perfringens	8-16 hours	24-48 hours	preformed toxin in meat, poultry, canned food	watery diarrhea
Enteric viruses, including rotavirus, adenovirus, astrovirus, and sapovirus	10-16 hours	2-9 days	contaminated food or water	watery diarrhea
Norovirus	24-48 hours	48-72 hours	molluscs, shellfish, leafy vegetables, fruit, sandwiches	watery diarrhea, with prominent vomiting
Rotavirus	24-48 hours	48-72 hours	molluscs, shellfish, leafy vegetables, fruit, sandwiches	watery diarrhea, with prominent vomiting
Listeria monocytogenes	24 hours	variable	processed meats, hot dogs, soft cheese, pâtés, and fruit	watery diarrhea
Enterotoxigenic Escherichia coli	1-3 days	2-3 days	contaminated food or water	watery diarrhea
Nontyphoidal Salmonella	1-3 days	1-7 days	poultry, eggs, fresh produce, meat, fish, unpasteurized juice or milk	inflammatory diarrhea, dysentery
Campylobacter species	1-3 days	5-14 days	poultry, meat, unpasteurized milk	inflammatory diarrhea, dysentery
Shigella species	1-3 days	2-3 days	raw vegetables, MSM	inflammatory diarrhea, dysentery
Enterohemorrhagic Escherichia coli	1-8 days	1 week	ground beef or other meat, fresh produce, unpasteurized milk and juice	inflammatory diarrhea, dysentery
Yersinia species	4-6 days	1-3 weeks	pork, untreated water	inflammatory diarrhea, dysentery
Giardia lamblia	7-14 days	days to weeks	contaminated food or water	watery diarrhea
Cyclospora cayetanensis	1-11 days	weeks	herbs and berries	watery diarrhea
Cryptosporidium parvum	2-28 days	weeks	vegetables, fruit, unpasteurized milk	watery diarrhea
Clostridioides difficile	—	variable	antibiotics, PPI use	watery or inflammatory diarrhea

Extraintestinal Complications

Complication	Bacteria						Parasites
	Campylobacter	Listeria	Salmonella	Shigella	STEC	Yersinia	Cyclospora	Entamoeba	Giardia
Aortitis			+			+
Deep tissue infection			+			+
Erythema nodosum	+		+	+		+
Glomerulonephritis	+			+		+
Guillain-Barré syndrome	+
Hemolytic anemia	+					+
Hemolytic-uremic syndrome				+†	+
IgA nephropathy	+
Intestinal perforation	+		+	+		+		+
Meningitis		+	+‡
Osteomyetlitis			+			+
Post-infectious IBS	+		+	+	+				+
Reactive arthritis	+		+	+		+	rare		rare

• †  Shigella dysenteriae serotype 1
• ‡  infants ≤3 months

Red Flags

• Duration >1 week
• Fever
• Bloody diarrhea
• Severe abdominal pain
• Dehydration, hypovolemia, shock
• Weight loss
• Recent antibiotic exposure
• Pregnancy
• Age over 65 years
• Diabetes, HIV, or other immunocompromising condition

Management

• Usually supportive, with a focus on rehydration
  • Oral rehydration if tolerating enough oral intake
  • Intravenous rehydration if not
• Antibiotics are indicated for:
  • Extraintestinal disease
  • Very young and very old
  • Immunocompromised
  • Severe symptoms including fever
  • Prolonged symptoms
• Choice of antibiotics is directed by the pathogen and local resistance patterns