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	24-48 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
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
Clostridium perfringens	8-16 hours	24-48 hours	meat, poulty, canned food	watery diarrhea
Enteric viruses, including rotavirus, adenovirus, astrovirus, and sapovirus	10-16 hours	2-9 days	contaminated food or water	watery diarrhea
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 dysenteriaea 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