Diarrhea

Diarrhea may be infectious or noninfectious and presents with acute (<14 days) or persistent (>14 days) symptoms. Community-acquired disease is most common. Viruses (norovirus predominates) are the most common cause of acute infectious diarrhea in community dwellers. Bacterial diarrhea represents only 1-5% of diarrhea cases and is often associated with clustering of cases or outbreaks. Clostridium difficile cases, while often nosocomially acquired, are increasing in community dwellers. Parasites are an infrequent or rare cause of acute diarrhea and tend to be sporadic in nature except in at-risk populations (eg, returned travelers, immunocompromised individuals).

Tabs Content

Clinical Overview

Diagnosis

Indications for Testing

Symptoms
- Persistent or chronic diarrhea
- Bloody diarrhea
- Diarrhea in association with systemic illness
Patient history
- Immunocompromised status
- Returned traveler
- Hospitalized patient
Outbreak identification

Laboratory Testing

Acute diarrhea (≤14 days)

Acute Diarrhea (≤14 Days)
Virus	Testing Options
For most cases, no testing is necessary at initial presentation – most etiologies of acute diarrhea are viral and do not require treatment Exceptions (Steffen, 2015) Immunocompromised or hospitalized patients Returned travelers with any of the following Fever >101.3F degrees Bloody stools Dysentery
Norovirus	Polymerase chain reaction (PCR) – most sensitive/specific test; available as a standalone test or in a viral panel Enzyme immunoasssay (EIA) (antigen detection) – not as sensitive as PCR Electron microscopy – insensitive and lab specific
Rotavirus	PCR – viral panel EIA – more sensitive than scanning electron microscopy (SEM) Immunochromatographic assay (ICA) – performs better than latex agglutination Latex agglutination – not recommended
Adenovirus 40/41	PCR – viral panel
Sapovirus, astrovirus	PCR – viral panel
Bacterial Testing
Indications	Testing Options
May be appropriate for certain groups (eg, returned travelers)	Stool culture Sensitivity highly variable; excellent specificity Sensitivity depends on specimen collection and transport Generally identifies Campylobacter, Salmonella, Shigella Should include E. coli for Shiga-like toxin by EIA (antigen) Sensitivity lower than PCR Turnaround time – 24-96+ hrs Gastrointestinal bacterial panel by PCR – detects the following Campylobacter jejuni/coli Campylobacter upsaliensis Salmonella spp Shiga-like toxin 1 from E. coli Shiga-like toxin 2 from E. coli Shigella spp/enteroinvasive E. coli (EIEC) Campylobacter antigen by enzyme immunoassay – may be used in place of culture Only specific for C. jejuni/C. coli For Yersinia and Vibrio spp – stool culture does not readily recover these spp; laboratory must include a specific culture condition or selective media for identification Clostridium difficile testing – refer to ARUP Consult topic
Parasitic Testing
Indications	Testing Options
May be indicated initially in the following Returned travelers with appropriate travel history Immunocompromised patients Community outbreaks	Do not use ova and parasite exams for most patients in acute setting Variable sensitivity Not cost effective Requires 3+ specimens Does not readily detect Cystoisospora, Cryptosporidium, Cyclospora, or microsporidia Cannot differentiate E. histolytica from E. dispar If parasitic testing deemed necessary – refer to testing options in persistent or chronic diarrhea table below

Persistent diarrhea (>14 days) or chronic diarrhea (>30 days)

Persistent (>14 Days) or Chronic Diarrhea (>30 Days)
Comprehensive Testing
Parasites often cause prolonged diarrhea; if no previous testing has been performed, consider also testing for Salmonella sp, Shigella sp, and Campylobacter spp (Steffen, 2015) Parasitic testing leads to highest yields at this stage
Organisms	Testing Options
Giardia lamblia/intestinalis/duodenalis Cryptosporidium hominis, C. parvum Entamoeba histolytica Cyclospora cayetanensis Dientamoeba fragilis	Gastrointestinal parasite polymerase chain reaction (PCR) panel Available with or without microsporidia PCR Very sensitive and specific for listed organisms
Individual Specific Organism Testing
Organism	Testing Options
Giardia duodenalis (synonyms Giardia lamblia, Giardia intestinalis)	Giardia antigen by enzyme immunoassay (EIA) – preferred if not using PCR panel If first specimen is negative and suspicion still exists, consider repeating for Giardia
Cryptosporidium hominis, C. parvum	Cryptosporidium spp antigen (EIA or direct fluorescent antibodies [DFA]) – preferred if not using PCR panel Microscopic detection in stool Requires special stains (eg, modified acid fast and multiple stool specimens) Less sensitive than stool EIA
Entamoeba histolytica	Intestinal disease Entamoeba antigen (EIA) preferred if not using PCR panel
Cystoisospora belli, Cyclospora cayetanensis	Microscopic examination of stool using special stain (eg, modified acid fast) if not using PCR
Dientamoeba fragilis	Ova and parasite exam – preferred if not using PCR panel Very difficult to identify in stains; insensitive
Microsporidia	Microscopic examination of stool using microsporidial stain (eg, modified acid fast) if not using PCR Stool examination May require testing of multiple specimens

Differential Diagnosis

Gastrointestinal disorders
- Postdiarrheal malabsorption
- Inflammatory bowel disease
- Irritable bowel syndrome
- Celiac disease
- Pancreatic insufficiency
- Diverticulitis
Immunodeficiency syndromes
Cystic fibrosis
Lactose intolerance
Malignancy
- Primary or metastatic cancer
  - Colorectal cancer
  - VIPoma syndrome
Laxative abuse

Background

Epidemiology

Incidence – the CDC estimates >350 million acute diarrheal incidences annually (Mead, 1999)
- The CDC's Foodborne Diseases Active Surveillance Network (FoodNet) reports ~48 million cases of foodborne illness annually

Risk Factors

Immunocompromised status
- HIV, primary immunodeficiency
  - Most common organisms include viruses, C. difficile, Campylobacter jejuni, Salmonella spp, E. coli, Giardia, Cryptosporidium spp, and microsporidia
- Transplantation (solid organ and stem cell)
  - Usually noninfectious
  - Infectious diarrhea most commonly caused by viruses (norovirus predominates), C. difficile, and microsporidia
Advanced age (>65 years)
- Salmonella spp and Shigella spp may require treatment, so identification is important
Comorbid illnesses (eg, chronic heart, liver, or kidney disease; diabetes mellitus)
- Increased risk of complications (eg, sepsis)
Institutional residency
- Norovirus
Daycare setting
- Norovirus
- Giardia
- Cryptosporidium spp
- Salmonella spp

Clinical Presentation

Community acquired
- Acute diarrhea (acute gastroenteritis)
  - Duration – 1-14 days
  - Transmission – foodborne, waterborne, or outbreak associated
  - Most commonly caused by viruses and occasionally bacteria
- Persistent diarrhea
  - Duration – >14 days, often longer
  - Often noninfectious
  - Testing for parasites may be considered
  - Persistent diarrhea may lead to malabsorption following an infectious diarrhea
Hospital acquired
- Presentation may be similar to community-acquired disease
- Most commonly caused by viruses
- Rule out bacterial agent C. difficile if patient history is correct

Organisms Associated with Diarrhea

The following organisms are associated with diarrhea (CDC, 2014).
- Norovirus
  Epidemiology
  Incidence
  Leading cause of nonbacterial gastroenteritis worldwide
  
  Norovirus causes millions of infections annually, with outbreaks commonly occurring in all age groups and in varied environments
  Cruise ships
  
  Restaurants (salad bar contamination most common)
  
  Schools
  
  Daycares
  
  Healthcare facilities
  
  Transmission
  Fecal-oral route by ingestion of contaminated food (eg, shellfish) or water
  
  Can be airborne (in vomitus)
  
  Low infectious dose; can survive relatively high levels of disinfectants and varying temperatures
  
  Clinical presentation
  Usually mild or self-limiting disease with high transmission rates
  
  Onset of symptoms occurs 24-48 hours after infection
  
  Symptoms – generally last 12-60 hours
  Acute onset diarrhea
  
  Vomiting with abdominal cramps
  
  Nausea
  
  Fever
  
  Headache
  
  Transplant patients often have chronic diarrhea
  Symptoms in small bowel transplant patients resemble allograft rejection
- Rotavirus
  Epidemiology
  Incidence
  Most important cause of severe dehydrating diarrhea worldwide in children <5 years
  Declined 67% in U.S. since introduction of vaccine
  
  Universal infection – nearly all children have circulating antibodies by 2-3 years
  
  Transmission
  Fecal-oral route
  
  Clinical presentation
  Varies from asymptomatic to severe dehydration leading to death
  
  Mild fever and emesis for 2-3 days
  
  Watery diarrhea for 3-5 days following fever
  Bloody diarrhea rare
  
  Severe and prolonged disease may occur in patients with the following
  Significant malnutrition
  
  Immune deficiencies (eg, HIV)
  
  Other chronic disease such as diabetes mellitus, congenital heart disease, or pulmonary disease
  
  May involve extra intestinal sites – central nervous system, liver, spleen, or kidney, especially in immunocompromised children
- Campylobacter
  Epidemiology
  Incidence
  Leading cause of bacterial gastroenteritis worldwide
  
  Peak incidence in children <5 years
  
  Occurrence
  Sporadic, but most cases occur in spring and fall
  
  Transmission
  Associated with incorrect food handling practices, consumption of poorly cooked poultry or raw milk, contact with pets, travel
  
  Outbreaks most often associated with raw milk and contaminated water
  
  Clinical presentation
  Varies from asymptomatic infection to severe inflammatory diarrhea
  
  Onset of symptoms occurs 2-5 days after ingestion of contaminated food or water
  
  Symptoms – generally last 7-10 days
  Abdominal pain
  
  Watery stools containing blood and mucous
  
  Fever
  
  Nausea or vomiting
  
  Complications
  Reactive arthritis (increased risk if individual is positive for HLA-B27 phenotype)
  
  Guillain-Barré syndrome
  
  Hemolytic uremic syndrome (HUS)
  
  Complications in patients with HIV or hypogammaglobulinemia – relapse osteomyelitis (especially with HLA-B27 phenotype)
  
  Local complications – hemorrhage, megacolon
  
  Bacteremic complications – cellulitis, meningitis
- Salmonella
  Epidemiology
  Incidence
  Most U.S. cases are related to international travel or immigrant status
  
  Remaining cases are from large, sporadic outbreaks
  Incidence nearly equal to Campylobacter
  
  Transmission
  Undercooked or uncooked foods (eg, raw meat and vegetables, poultry, eggs, milk, salad dressing, shrimp, peanut butter)
  
  Contact with infected animals
  
  Contact with nonsymptomatic patients
  
  Clinical presentation
  Typhoid fever
  Incubation period is 3-21 days
  
  Prodrome of chills, headache, sore throat, fever, anorexia, cough
  
  Progresses to rash (rose spots), epistaxis, diarrhea, relative bradycardia
  
  Blood cultures are of higher yield than stool cultures for typhoid fever
  90% have positive blood cultures in week 1; drops to 50% by week 3
  
  Complications
  Late complications found in untreated adults – intestinal perforation, gastrointestinal hemorrhage
  
  Rare complications – pancreatitis, hepatic and splenic abscesses, endocarditis, pericarditis, orchitis, meningitis, parotitis, osteomyelitis
  
  Up to 5% of infected patients develop chronic carrier state
  Usually occurs in patients with gall bladder disease or gastric carcinomas
  
  Enteritis
  Onset of symptoms occur 6-48 hours after exposure
  
  Symptoms – gererally last 1-2 days
  Fever, headache
  
  Intestinal symptoms – diarrhea (watery), abdominal pain
- Shiga-toxigenic E. coli
  Epidemiology
  Incidence
  Under-recognized illness
  
  Not uncommon
  
  Transmission
  Person-to-person contact in daycare facilities and nursing homes
  
  Consumption of undercooked meats and produce (washing produce has been shown to be ineffective)
  
  Clinical presentation
  Watery diarrhea progressing to bloody diarrhea
  
  Abdominal pain
  
  Symptoms usually resolve within 8 days
  
  Hemolytic uremia syndrome (HUS) – fever, renal dysfunction and hemolytic anemia, thrombocytopenia
  Virulence is attributable to production of Shiga-like toxin 1 and/or 2
  
  Most frequent in children <15 years and adults >65 years
- Shigella spp
  Epidemiology
  Incidence
  Common in countries with poor sanitation
  
  Accounts for small percentage of reported outbreaks of foodborne illness in U.S.
  
  Transmission
  Fecal-oral route; no nonhuman hosts
  
  Higher-risk groups – daycare personnel and clients, nursing home residents, and men who have sex with men
  
  Clinical presentation
  Onset of symptoms occurs 12-50 hours after exposure
  
  Symptoms
  Diarrhea
  Frequently bloody
  
  May contain mucous or pus
  
  Fever
  
  Abdominal pain, cramps
  
  Dysentery (10-30 stools/day)
  
  Associated with Reiter syndrome (arthritis, uveitis, urethritis)
  
  Complications
  Reactive arthritis (increased risk of development if patient is positive for HLA-B27 allele)
  
  Hemolytic uremic syndrome (HUS) (usually S. dysenteriae type 1)
- Yersinia spp
  Epidemiology
  Incidence
  Most often in young children
  
  Y. pseudotuberculosis and Y. pestis are uncommon causes of gastrointestinal disease
  
  Transmission
  Soil, water, animals, food
  
  Y. enterocolitica found in meats (eg, beef, pork), oysters, fish, and unpasteurized milk
  
  Clinical presentation
  Onset of symptoms occurs 24-48 hours after ingestion of contaminated food or drink
  
  Symptoms
  Diarrhea (loose, watery, or bloody stools)
  
  Abdominal pain
  
  Fever
  
  Infections with Y. enterocolitica and Y. pseudotuberculosis can be asymptomatic, mild, or severe, with infection resolving within a few weeks (with or without use of antibiotics)
  
  Yersinia infections are known for mimicking appendicitis
  
  Complications include reactive arthritis which can manifest 1-4 weeks post infection (increased risk of development if patient is positive for HLA-B27 allele)
  The most commonly affected joints are knees and ankles, but other joints such as toes, fingers, and wrists can be involved
  
  In most cases, 2-4 joints become involved sequentially and asymmetrically over a period of a few days to 2 weeks
  Joint fluid is sterile
  
  Chronic joint disease or ankylosing spondylitis occurs rarely
  
  Acute arthritis persists for 1-4 months
  
  Reiter syndrome (arthritis, uveitis, and urethritis) may occur
  
  Less common nonsuppurative sequelae of Y. enterocolitica infections include reactive uveitis, iritis, conjunctivitis, glomerulonephritis, urethritis, hemolytic uremic syndrome (HUS)
- Vibrio spp
  Epidemiology
  Incidence
  Vibrio cholerae
  Several pandemics have occurred
  
  No major outbreaks in U.S. since 1911
  
  V. vulnificus
  Outbreak reported in New Orleans after hurricane Katrina
  
  Usually several lethal cases annually in Florida, typically in summer months
  
  Transmission
  Ingestion of contaminated seafood (eg, crab, shrimp, lobster)
  V. parahaemolyticus is the leading cause of bacterial diarrhea associated with seafood
  
  Through open wounds in sea water
  
  Clinical presentation
  Onset of symptoms occurs within 16 hours of ingestion of contaminated seafood for healthy individuals
  
  Symptoms
  Watery diarrhea
  
  Abdominal pain
  
  Cramps
  
  Vomiting
  
  Immunocompromised individuals and patients with cirrhosis may present with primary septicemia
  Associated with >50% mortality
  
  No associated long-term complications
- Giardia duodenalis (synonyms Giardia lamblia, Giardia intestinalis)
  Epidemiology
  Incidence
  Most common cause of parasite-associated diarrhea in the U.S.
  
  Increased frequency in children, men who have sex with men, and residents of institutional care facilities
  
  Transmission
  Waterborne, foodborne, or fecal-oral
  
  Clinical presentation
  Most infections are asymptomatic
  
  Symptoms may last from weeks to months
  Acute or chronic nonbloody diarrhea, nausea, vomiting, dehydration, abdominal discomfort, malabsorptive symptoms (eg, flatulence, greasy malodorous stools)
  
  Intermittent or recurrent symptoms are common
- Cryptosporidium spp
  Epidemiology
  Incidence
  Increased risk in patients with HIV, residents of households with infected patients, daycare personnel and clients, and returned travelers
  
  Transmission
  Waterborne, sporadic, or outbreak associated
  Found in large outbreaks associated with contaminated water sources
  
  Can occur year round when artificial water storage systems are involved
  
  Clinical presentation
  Immunocompetent patients
  Usually asymptomatic or mild, self-limiting gastroenteritis
  
  Nonbloody, watery diarrhea, dehydration, nausea, vomiting, abdominal pain, low-grade fever, and malaise lasting from a few days to >30 days
  
  Immunocompromised patients
  General immunodeficiencies (particularly T-cell deficiencies) – chronic diarrhea (often more severe than expected for pathogen), dehydration, weight loss
  
  HIV – chronic diarrhea; others include cholecystitis, hepatitis, pancreatitis
- Entamoeba histolytica
  Epidemiology
  Incidence
  Increased risk in men who have sex with men, recent immigrants, residents of institutional care facilities, returned travelers, and HIV patients
  
  Typically limited to individual cases with possible spread to sex partners or close contacts
  
  Transmission
  Waterborne, foodborne, or fecal-oral
  
  Clinical presentation
  Most individuals are asymptomatically colonized (~90%)
  Subacute onset
  
  Disease may be intestinal or extraintestinal
  Intestinal disease
  Fulminant or chronic, with abdominal pain, tenderness, tenesmus, and bloody diarrhea
  
  Extraintestinal disease
  May include liver, brain, and lung abscesses
- Cystoisospora belli
  Epidemiology
  Incidence
  Increased risk in HIV patients, recent immigrants, and travelers from endemic regions
  
  Transmission
  Waterborne
  
  Clinical presentation
  Immunocompetent patients
  Acute, self-limiting watery or malodorous diarrhea (similar to Giardia or Cryptosporidium infection)
  
  Immunocompromised patients
  General immunodeficiencies – chronic diarrhea (occasionally severe), dehydration, weight loss
  
  HIV – diarrhea, cholecystitis, reactive arthritis
- Microsporidia
  Epidemiology
  Incidence
  Undetermined in non-HIV populations
  
  Increased risk in HIV patients presenting with chronic diarrhea
  Predominately affects immunocompromised hosts
  
  Includes Enterocytozoon bieneusi, Encephalitozoon intestinalis, Pleistophora, Septata, Vittaforma spp
  
  ~15% prior to combination antiretroviral therapy (cART)
  
  Rates are lower for patients on cART
  
  Transmission
  Waterborne
  
  Clinical presentation
  Immunocompetent patients
  Rare cause of acute, self-limiting diarrhea
  
  Immunocompromised patients (most often with HIV)
  Chronic diarrhea, dehydration, anorexia, weight loss, abdominal pain, nausea, vomiting
- Cyclospora cayetanensis
  Epidemiology
  Incidence
  Unknown in U.S.; usually tropical/subtropical regions
  
  Transmission
  Foodborne or waterborne
  
  Clustered outbreaks associated with contaminated food products
  
  Recent outbreaks occurring at higher frequency
  Not associated with foreign travel, but rather, foreign food products sold domestically
  
  Clinical presentation
  Immunocompetent patients
  Anorexia, nausea, emesis, flatulence, watery diarrhea, low grade fever, fatigue, cramping
  
  Typically does not resolve without treatment
  
  Immunocompromised patients
  May cause chronic diarrhea
  
  Endemic – frequent mild or asymptomatic cases

ARUP Lab Tests

Tests generally appear in the order most useful for common clinical situations. Click on number for test-specific information in the ARUP Laboratory Test Directory.

Gastrointestinal Viral Panel by PCR 2013577
Method: Qualitative Polymerase Chain Reaction

Recommended Use

Aid in the diagnosis of GI infections caused by viral pathogens, including adenovirus (serotypes 40 and 41), astrovirus, norovirus (genogroups 1 and 2), rotavirus, and sapovirus

Use as a sensitive alternative to traditional antigen testing

Norovirus, Groups 1 and 2 by PCR 2014546
Method: Qualitative Reverse Transcription Polymerase Chain Reaction

Recommended Use

Detect Norovirus groups 1 and 2

Rotavirus Antigen by EIA 0065088
Method: Qualitative Enzyme Immunoassay

Recommended Use

Diagnose rotavirus-associated gastroenteritis

For antigen testing panel that includes adenovirus and rotavirus, refer to rotavirus and adenovirus 40-41 antigens

Stool Culture and E. coli Shiga-like Toxin by EIA 0060134
Method: Culture/Identification

Recommended Use

Preferred test for suspected bacterial diarrhea evaluation

Testing includes cultures for Salmonella, Shigella, Campylobacter, E. coli O157, and EIA for Shiga-like toxin from E. coli

Can be used to rule out Aeromonas and Plesiomonas; specify the pathogen to rule out

For C. difficile testing, refer to Clostridium difficile toxin B gene by PCR

Limitations

If an isolate requires testing for Shiga-like toxin (eg, STEC), refer to E. coli Shiga-like toxin by EIA

Gastrointestinal Bacterial Panel by PCR 2012678
Method: Qualitative Polymerase Chain Reaction

Recommended Use

Use as a sensitive alternative to traditional stool culture to detect the most common gastrointestinal bacterial pathogens: Salmonella, Shigella/Enteroinvasive E. coli, Campylobacter jejuni/coli, and shiga-toxigenic E. coli

This test can also detect Campylobacter upsaliensis, which cannot be readily cultured

Limitations

A negative result does not rule out the presence of PCR inhibitors in the patient specimen or test-specific nucleic acid in concentrations below the level of detection by this test

Gastrointestinal Parasite and Microsporidia by PCR 2011660
Method: Qualitative Polymerase Chain Reaction

Recommended Use

Do not order for patients with diarrhea developed during prolonged hospitalization

Most comprehensive and sensitive alternative to traditional, insensitive ova and parasite examinations of stool specimens for the evaluation of gastrointestinal infections

Detect Cryptosporidium hominis, C. parvum, Cyclospora cayetanensis, Dientamoeba fragilis, Entamoeba histolytica, Giardia lamblia/intestinalis/duodenalis, and microsporidia by PCR

Clostridium difficile toxin B gene (tcdB) by PCR 2002838
Method: Qualitative Polymerase Chain Reaction

Recommended Use

Recommended rapid, stand-alone diagnostic test for C. difficile-associated diarrhea

Gastrointestinal Parasite Panel by PCR 2011150
Method: Qualitative Polymerase Chain Reaction

Recommended Use

Do not order for patients with diarrhea developed during prolonged hospitalization

Use as a sensitive alternative to traditional, insensitive ova and parasite examinations of stool specimens

Detect Cryptosporidium hominis, C. parvum, Cyclospora cayetanensis, Dientamoeba fragilis, Entamoeba histolytica, and Giardia lamblia/intestinalis/duodenalis

Giardia Antigen by EIA 0060048
Method: Qualitative Enzyme Immunoassay

Recommended Use

Test for persistent diarrhea (>14 days) or known risk factors if Giardia duodenalis (synonyms Giardia lamblia, Giardia intestinalis) is the suspected infectious agent

Cryptosporidium Antigen by EIA 0060045
Method: Qualitative Enzyme Immunoassay

Recommended Use

Test for persistent diarrhea (>14 days) or known risk factors if Cryptosporidium spp is the suspected infectious agent

Parasitology Stain by Modified Acid-Fast 0060046
Method: Qualitative Concentration/Stain

Recommended Use

Test for persistent diarrhea (>14 days) or known risk factors if Cryptosporidium, Cyclospora, or Cystoisospora is the suspected infectious agent

Microsporidia by PCR 2011626
Method: Qualitative Polymerase Chain Reaction

Recommended Use

Preferred test to diagnose microsporidia in immunocompromised patients with persistent diarrhea if Encephalitozoon spp (E. instestinalis/E. hellem/E. cuniculi) or Enterocytozoon bieneusi is the suspected infectious agent

Limitations

The nucleic acid from E. intestinalis, E. hellem, and E. cuniculi will be detected by this test but cannot be differentiated

A negative result does not rule out the presence of PCR inhibitors in the patient specimen or test-specific nucleic acid in concentrations below the level of detection by this test

Microsporidia Stain by Modified Trichrome 0060050
Method: Qualitative Stain

Recommended Use

Can be used for follow-up of negative PCR result when suspicion of microsporidia infection remains high

Entamoeba histolytica Antigen, EIA 0058001
Method: Qualitative Enzyme Immunoassay

Recommended Use

Test for persistent diarrhea (>14 days) or known risk factors if E. histolytica is the suspected infectious agent

Ova and Parasite Exam, Fecal (Immunocompromised or Travel History) 2002272
Method: Qualitative Concentration/Trichrome Stain/Microscopy

Recommended Use

If parasite infection is suspected as cause of persistent diarrhea (>14 days), specific pathogen testing is recommended

Do not order for patients who develop diarrhea during a prolonged hospitalization

Limitations

Due to the various shedding cycles of many parasites, 3 separate stool specimens collected over a 5- to 7-day period are recommended for ova and parasite examination

A single negative result does not rule out the possibility of a parasitic infection

Stool antigen testing is the optimal test method for determining the parasitic presence of Giardia, Cryptosporidium spp, or Entamoeba histolytica

Does not specifically detect Cryptosporidium, Cyclospora, Cystoisospora, or microsporidia

Follow-up

For Cryptosporidium, refer to the Cryptosporidium antigen by EIA test; for Cyclospora and Cystoisospora, refer to parasitology stain by modified acid-fast; for microsporidia, refer to microsporidia stain

Medical Experts

Couturier, Marc Roger, PhD, D(ABMM), Medical Director, Microbial Immunology, Parasitology and Fecal Testing, and Infectious Disease Antigen Testing at ARUP Laboratories; Associate Professor of Clinical Pathology, University of Utah

Fisher, Mark A., PhD, D(ABMM), Medical Director, Bacteriology, and Special Microbiology, Antimicrobial Susceptibility Testing, at ARUP Laboratories; Associate Professor of Clinical Pathology, University of Utah

Hillyard, David R., MD, Medical Director, Molecular Infectious Diseases at ARUP Laboratories; Professor of Clinical Pathology, Adjunct Professor of Biology, University of Utah

Schlaberg, Robert, MD, MPH, Medical Director, Microbial Amplified Detection, Virology, and Fecal Chemistry; and Assistant Medical Director, Virology and Molecular Infectious Disease at ARUP Laboratories; Assistant Professor of Clinical Pathology, University of Utah

References

Guidelines

Foodborne Diseases Active Surveillance Network (FoodNet). Centers for Disease Control and Prevention. Atlanta, GA [Last updated: Nov 2016; Accessed: Dec 2016]
Guerrant RL, Van Gilder T, Steiner TS, Thielman NM, Slutsker L, Tauxe RV, Hennessy T, Griffin PM, DuPont H, Sack RB, Tarr P, Neill M, Nachamkin I, Reller LB, Osterholm MT, Bennish ML, Pickering LK, Infectious Diseases Society of America. Practice guidelines for the management of infectious diarrhea. Clin Infect Dis. 2001; 32(3): 331-51. PubMed
Manatsathit S, DuPont HL, Farthing M, Kositchaiwat C, Leelakusolvong S, Ramakrishna BS, Sabra A, Speelman P, Surangsrirat S, Working Party of the Program Committ of the Bangkok World Congress of Gastroenterology 2002. Guideline for the management of acute diarrhea in adults. J Gastroenterol Hepatol. 2002; 17 Suppl: S54-71. PubMed
Centers for Disease Control and Prevention. Manual for the Surveillance of Vaccine-Preventable Diseases. Centers for Disease Control and Prevention. Atlanta, GA [Updated: Apr 2018; Accessed: Jul 2019]
Riddle MS, DuPont HL, Connor BA. ACG Clinical Guideline: Diagnosis, Treatment, and Prevention of Acute Diarrheal Infections in Adults. Am J Gastroenterol. 2016; 111(5): 602-22. PubMed
Farthing M, Salam MA, Lindberg G, Dite P, Khalif I, Salazar-Lindo E, Ramakrishna BS, Goh K, Thomson A, Khan AG, Krabshuis J, LeMair A, WGO. Acute diarrhea in adults and children: a global perspective. J Clin Gastroenterol. 2013; 47(1): 12-20. PubMed

General References

Barr W, Smith A. Acute diarrhea. Am Fam Physician. 2014; 89(3): 180-9. PubMed

Bernstein DI. Rotavirus overview. Pediatr Infect Dis J. 2009; 28(3 Suppl): S50-3. PubMed

Calderaro A, Gorrini C, Montecchini S, Peruzzi S, Piccolo G, Rossi S, Gargiulo F, Manca N, Dettori G, Chezzi C. Evaluation of a real-time polymerase chain reaction assay for the laboratory diagnosis of giardiasis. Diagn Microbiol Infect Dis. 2010; 66(3): 261-7. PubMed

DuPont HL. Clinical practice. Bacterial diarrhea. N Engl J Med. 2009; 361(16): 1560-9. PubMed

Glass RI, Parashar UD, Estes MK. Norovirus gastroenteritis. N Engl J Med. 2009; 361(18): 1776-85. PubMed

Graves NS. Acute gastroenteritis. Prim Care. 2013; 40(3): 727-41. PubMed

Grimwood K, Forbes DA. Acute and persistent diarrhea. Pediatr Clin North Am. 2009; 56(6): 1343-61. PubMed

Hill DR, Ryan ET. Management of travellers' diarrhoea. BMJ. 2008; 337: a1746. PubMed

Hunt JM. Shiga toxin-producing Escherichia coli (STEC). Clin Lab Med. 2010; 30(1): 21-45. PubMed

Khan MA, Bass DM. Viral infections: new and emerging. Curr Opin Gastroenterol. 2010; 26(1): 26-30. PubMed

Mathis A, Weber R, Deplazes P. Zoonotic potential of the microsporidia. Clin Microbiol Rev. 2005; 18(3): 423-45. PubMed

Mead PS, Slutsker L, Dietz V, McCaig LF, Bresee JS, Shapiro C, Griffin PM, Tauxe RV. Food-related illness and death in the United States. Emerg Infect Dis. 1999; 5(5): 607-25. PubMed

Patel MM, Hall AJ, Vinjé J, Parashar UD. Noroviruses: a comprehensive review. J Clin Virol. 2009; 44(1): 1-8. PubMed

Pawlowski SW, Warren CA, Guerrant R. Diagnosis and treatment of acute or persistent diarrhea. Gastroenterology. 2009; 136(6): 1874-86. PubMed

Pierce KK, Kirkpatrick BD. Update on human infections caused by intestinal protozoa. Curr Opin Gastroenterol. 2009; 25(1): 12-7. PubMed

Recommendations for Diagnosis of Shiga Toxin–Producing Escherichia coli Infections by Clinical Laboratories. October 16, 2009, Vol. 58, No. RR-12. Centers for Disease Control and Prevention. Atlanta, GA [Published: Oct 2009; Accessed: Jan 2017]

Steffen R, Hill DR, DuPont HL. Traveler's diarrhea: a clinical review. JAMA. 2015; 313(1): 71-80. PubMed

Resources from the ARUP Institute for Clinical and Experimental Pathology®

Beal SG, Couturier MR, Gander RM, Doern CD. Diagnostic Algorithm for the Diagnosis of Pediatric Parasitic Gastroenteritis. J Clin Lab Anal. 2016; 30(2): 155-60. PubMed

Couturier BA, Hale DC, Couturier MR. Association of Campylobacter upsaliensis with persistent bloody diarrhea. J Clin Microbiol. 2012; 50(11): 3792-4. PubMed

Couturier BA, Jensen R, Arias N, Heffron M, Gubler E, Case K, Gowans J, Couturier MR. Clinical and Analytical Evaluation of a Single-Vial Stool Collection Device with Formalin-Free Fixative for Improved Processing and Comprehensive Detection of Gastrointestinal Parasites J Clin Microbiol. 2015; 53(8): 2539-48. PubMed

Filkins LM, Gaston DC, Mathison B, Smith T, Couturier MR, Murphy RD, Ciarkowski C, Hanson KE, Cariello PF. Biliary With Cholecystitis and Extensive Portal Vein Thrombosis. Open Forum Infect Dis. 2017; 4(4): ofx217. PubMed

Khot PD, Fisher MA. Novel approach for differentiating Shigella species and Escherichia coli by matrix-assisted laser desorption ionization-time of flight mass spectrometry. J Clin Microbiol. 2013; 51(11): 3711-6. PubMed

Rossi A, Couturier MR. The Brief Case: Cryptosporidiosis in a Severely Immunocompromised HIV Patient. J Clin Microbiol. 2016; 54(9): 2219-21. PubMed

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April 2017

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	Diarrhea. ARUP Consult^©. Retrieved August 13, 2019, from: https://arupconsult.com/content/diarrhea

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Diarrhea

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Laboratory Testing

Differential Diagnosis

Background

Epidemiology

Risk Factors

Clinical Presentation

Organisms Associated with Diarrhea

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Resources from the ARUP Institute for Clinical and Experimental Pathology®

Diarrhea in Healthy Pediatric Patients Testing Algorithm

Diarrhea in Hospitalized Adult Patients Testing Algorithm

Diarrhea in Immunocompromised Hosts Testing Algorithm

Diarrhea in Primary Care Adults Testing Algorithm

Diarrhea in Returned Traveller or Immigrant Testing Algorithm

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