Sandbox:GE

Classification

Gastroenteritis

Viral

Bacterial

Parasites

Common

Less Common

Common

Less Common

Helminthic

Protozoal

❑Rotavirus ❑Norovirus ❑Enteric Adenovirus ❑Astroviruses

❑Kobuviruses ❑Enterovirus ❑Orthoreovirus ❑Torovirus ❑Coronavirus (including SARS) ❑Parvovirus

Gram Positive

Gram Negative

Gram Positive

Gram Negative

❑Trichinella spiralis ❑Trichuris trichiura ❑Strongyloides stercoralis ❑Taenia solium ❑Taenia saginata ❑Diphyllobothrium latum ❑Schistosoma mansoni

❑Giardia lamblia ❑Entamoeba histolytica‡ ❑Cryptosporidium parvum ❑Cyclospora cayetanensis

❑Clostridium perfringens ❑Clostridium difficile

Dysentric diarreha

Watery diarrhea

❑ Bacillus cereus ❑Listeria monocytogenes

❑Bacteroides fragilis ❑Aeromonas hydrophila

❑Shigella sp., ❑Campylobactersp.

❑Escherichia coli (ETEC, EPEC, EHEC, EAEC, EIEC)§ ❑Salmonella sp.† ❑Yersinia enterocolitica† ❑Vibrio cholerae ❑Vibrio parahemolyticus

§ EHEC, EIEC, EPEC and EAEC may cause bloody diarrhea, but they are classically associated with watery diarrhea.
† Either Salmonella and Yersinia can cause dysentery.
‡ Entamoeba histolytica may cause dysentery

Patient Evaluation

Initial Management

Shown below is an algorithm depicting the initial management of acute diarrhea is based on the 2001 IDSA practice guidelines for the management of infectious diarrhea.

Characterize the symptoms: ❑ Onset ❑ Duration ❑ Pattern (continuous or intermittent) ❑ Stool characteristic (watery, bloody, mucous or greasy) ❑ Frequency of bowel movements ❑ Dysenteric symptoms (fever, tenesmus, blood and/or pus in stool) Associated symptoms: ❑ Abdominal pain ❑ Nausea and vomiting ❑ Weight loss Epidemiological factors: ❑ Travel ❑ Food (raw meat, eggs, shellfish, unpasteurized cheese or milk) ❑ Outbreaks ❑ Sexual history ❑ Day care attendance ❑ Previous evaluations ❑ Medications, radiation therapy or surgery ❑ Underlying medical condition (cancer, diabetes, hyperthyroidism or AIDS)

Examine the patient: ❑ Temperature ❑ Pulse ❑ Blood pressure ❑ Respiratory rate ❑ Signs of volume depletion (decreased skin turgor, dry mucosa) ❑ Abdominal tenderness ❑ Level of consciousness

Assessment of volume status General condition Normal Irritable/less active* Lethargic/comatose§ Eyes Normal Sunken - Mucosa Normal Dry - Thirst Normal Thirsty Unable to drink§ Radial pulse Normal Low volume* Absent/ uncountable§ Skin turgor Normal Reduced - † Some dehydration = At least two signs, including at least one key sign (*) are present. ‡ Severe dehydration = Signs of “some dehydration” plus at least one key sign (§) are present.

No dehydration

Some dehydration

Severe dehydration

Start altered diet ❑ Stop lactose products ❑ Avoid alcohol and high osmolar supplements ❑ Drink 8-10 large glasses of clear fluids (Fruit juices, soft drinks etc) ❑ Eat frequent small meals (Rice, potato, banana, pastas etc) Can start oral rehydration therapy (ORT) for replacement of stool losses

❑ Start ORT at a volume of 50-100 mL/kg ❑ Start altered diet ❑ Reassess status every 4 hr

❑ Start IV fluids: Ringer lactate at 30ml/kg in the first 1/2hr and 70ml/kg for the next 2 1/2 hr, if unavailable use normal saline ❑ CBC ❑ Electrolytes ❑ Assess status every 15 mins until strong pulse felt and then every 1 hr

Patient stable and able to drink ❑ Start ORT at a volume of 100 mL/kg over 4 hour ❑ Calculate the continuing stool and emesis losses every hour for additional maintenance ORT therapy ❑ Reassess status every 4 hr

Hemodynamic stabilized Proceed to Diagnosis and Management

Diagnostic and Management approach

Passage of ≥3 unformed stools in 24 h + An enteric symptom (nausea, vomiting, abdominal pain/cramps, tenesmus, fecal urgency, moderate to severe flatulence)                                                                                                               Watery diarrhea ± Vomiting                                   Dysenteric diarrhea (passage of grossly bloody stools)                                                                                                               Mild Illness†             Moderate to Severe†               No or low-grade fever(≤100°F)       Severe illness† with fever≥(101°F) in a single case (not outbreak)                                                                                                           Hydration only May use loperamide 4 mg initially to control stooling   Travel associated         Non travel associated                   Non travel associated     Travel associated                                                                                                   Antibiotic therapy   No or low-grade fever (≤100°F)       Fever (≥101°F)                         Empiric treatment Azithromycin 1 g in single dose OR 500 mg once daily for 3 days                                                                                                     <72 h duration   ≥72 h duration                                                                                                         Loperamide therapy for 48 h                                                                                   Microbiologic assessment and appropriate treatment                                                                                                                                                                                                                                                                                                                                                                                                                                           Persistent diarrhea (14–30 days) should be worked up by culture and/or culture independent microbiologic assessment, then treatment with anti microbial agent directed to cause

†Illness severity:

• Severe: Total disability due to diarrhea;
• Moderate: Able to function but with forced change in activities due to illness;
• Mild: No change in activities

Synopsis

Organism			Age predilection	Travel History	Incubation Size (cell)	Incubation Time	History and Symptoms			Diarrhea type∞				Food source	Specific consideration
							Fever	N/V	Cramping Abd Pain	Small Bowel	Large Bowel	Inflammatory	Non-inflammatory
Viral	Rotavirus		<2 y	-	<102	<48 h	✔	✔	-	✔			✔	-	Mostly in day cares, most common in winter.
	Norovirus		Any age	-	10 -103	24-48 h	✔	✔	✔	✔			✔	-	Most common cause of gastroenteritis, abdominal tenderness,
	Adenovirus		<2 y	-	105 -106	8-10 d	✔	✔	✔	✔			✔	-	No seasonality
	Astrovirus		<5 y	-		72-96 h	✔	✔	✔	✔			✔	Seafood	Mostly during winter
Bacterial	Escherichia coli	ETEC	Any age	✔	108 -1010	24 h	-	✔	✔	✔			✔	-	Causes travelers diarrhea, contains heat-labile toxins (LT) and heat-stable toxins (ST)
		EPEC	<1 y	-	10†	6-12 h	-	✔	✔	✔			✔	Raw beef and chicken	-
		EIEC	Any ages	-	10†	24 h	✔	✔	✔		✔		✔	Hamburger meat and unpasteurized milk	Similar to shigellosis, can cause bloody diarrhea
		EHEC	Any ages	-	10	3-4 d	-	✔	✔		✔	✔		Undercooked or raw hamburger (ground beef)	Known as E. coli O157:H7, can cause HUS/TTP.
		EAEC	Any ages	✔	1010	8-18 h	-	-	✔		✔		✔	-	May cause prolonged or persistent diarrhea in children
	Salmonella sp.		Any ages	✔	1	6 to 72 h	✔	✔	✔		✔	✔		Meats, poultry, eggs, milk and dairy products, fish, shrimp, spices, yeast, coconut, sauces, freshly prepared salad.	Can cause salmonellosis or typhoid fever.
	Shigella sp.		Any ages	-	10 - 200	8-48 h	✔	✔	✔		✔	✔		Raw foods, for example, lettuce, salads (potato, tuna, shrimp, macaroni, and chicken)	Some strains produce enterotoxin and Shiga toxin similar to those produced by E. coli O157:H7
	Campylobacter sp.		<5 y, 15-29 y	-	104	2-5 d	✔	✔	✔		✔	✔		Undercooked poultry products, unpasteurized milk and cheeses made from unpasteurized milk, vegetables, seafood and contaminated water.	May cause bacteremia, Guillain-Barré syndrome (GBS), hemolytic uremic syndrome (HUS) and recurrent colitis
	Yersinia enterocolitica		<10 y	-	104 -106	1-11 d	✔	✔	✔		✔	✔		Meats (pork, beef, lamb, etc.), oysters, fish, crabs, and raw milk.	May cause reactive arthritis; glomerulonephritis; endocarditis; erythema nodosum. can mimic appendicitis and mesenteric lymphadenitis.
	Clostridium perfringens		Any ages		> 106	16 h	-	-	✔		✔		✔	Meats (especially beef and poultry), meat-containing products (e.g., gravies and stews), and Mexican foods.	Can survive high heat,
	Vibrio cholerae		Any ages	-	106-1010	24-48 h	-	✔	✔	✔			✔	Seafoods, including molluscan shellfish (oysters, mussels, and clams), crab, lobster, shrimp, squid, and finfish.	Hypotension, tachycardia, decreased skin turgor. Rice-water stools
Parasites	Protozoa	Giardia lamblia	2-5 y	✔	1 cyst	1-2 we	-	-	✔	✔			✔	Contaminated water	May cause malabsorption syndrome and severe weight loss
		Entamoeba histolytica	4-11 y	✔	<10 cysts	2-4 we	-	✔	✔		✔	✔		Contaminated water and raw foods	May cause intestinal amebiasis and amebic liver abscess
		Cryptosporidium parvum	Any ages	-	10-100 oocysts	7-10 d	✔	✔	✔	✔			✔	Juices and milk	May cause copious diarrhea and dehydration in patients with AIDS especially with 180 > CD4
		Cyclospora cayetanensis	Any ages	✔	10-100 oocysts	7-10 d	-	✔	✔	✔			✔	Fresh produce, such as raspberries, basil, and several varieties of lettuce.	More common in rainy areas
	Helminths	Trichinella spp	Any ages	-	Two viable larvae (male and female)	1-4 we	-	✔	✔	-	✔		✔	Undercooked meats	More common in hunters or people who eat traditionally uncooked meats
		Taenia spp	Any ages	-	1 larva or egg	2-4 m	-	✔	✔	✔			✔	Undercooked beef and pork	Neurocysticercosis: Cysts located in the brain may be asymptomatic or seizures, increased intracranial pressure, headache.
		Diphyllobothrium latum	Any ages	-	1 larva	15 d	-	-	-	✔			✔	Raw or undercooked fish.	May cause vitamin B12 deficiency

Prevention

❑ E.Coli species
❑ Salmonella species
❑ Shigella
❑ Campilobacter
❑ Vibrio species|D04=❑ Bacillus cereus
❑ Bacteroids fragilis
❑ Aeromonas
❑ Staphylococcus aureus