Topic Editor: Grant E. Fraser, M.D., FRACGP, FACRRM, ASTEM

Review Date: 9/17/2012

Definition

Traveler's diarrhea is defined as diarrhea characterized by 3 unformed stools over a period of 24 hours occurring during travel to a less economically developed country

Description

• It is the most common illness affecting people traveling to less economically developed countries
• The primary source of infection is consumption of food or water contaminated by fecal matter
• This condition starts abruptly with increased frequency (3 bowel movements/day) and volume of stools, accompanied by symptoms such as abdominal cramping, bloating, fever, vomiting, and malaise
• Depending upon the pathogen and the affected individual, stools may be watery, have mucous, contain blood, or simply be looser than normal
• This is generally a self-limiting condition, usually lasting for about 3-5 days. Most bacterial and viral cases resolve with no specific treatment

Epidemiology

Incidence/Prevelence

• This condition affects 20-50% of travelers with up to 40 million cases each year
• The risk is determined by the traveler's destination. High risk regions include Latin America, Central America, Africa, the Middle East, and Asia

Age

• Young adults are more commonly affected by this condition

Gender

• Affects both men and women; however, women may be more susceptible

Risk Factors

• Age < 30 years
• Consumption of contaminated food or liquid
• Diabetes
• Immunocompromised patients
• Inflammatory bowel disease
• No previous travel history to high-risk areas
• Suppressed gastric acidity
• Travel to high-risk areas
• Travel during monsoons

Etiology

• The primary causes of traveler's diarrhea are infectious pathogens including bacteria, viruses and parasites
• Most cases are due to consumption of bacterially contaminated food or water, usually due to fecal contamination
• Escherichia coli (enterotoxigenic and enteroaggregative or diarrheagenic) is the most common pathogen, found in 60–72% of cases
• Other organisms causative of traveller's diarrhea include:
  • Bacteria
    • Aeromonas
    • Campylobacter jejuni
    • Clostridium difficile
    • Plesiomonas
    • Salmonella
    • Shigella
    • Vibrio (non-cholera)
    • Yersinia
  • Viruses
    • Enterovirus
    • Norovirus (Norwalk virus)
    • Rotavirus (mainly in children)
  • Parasites
    • Cryptosporidium parvum
    • Cyclospora cayetanensis
    • Entamoeba histolytica
    • Giardia duodenalis (Giardiasis)
    • Isospora belli

Pathophysiology

• Most organisms enter the gut through contaminated food/water and survive through the stomach to cause enteric infection
• Species that are more invasive attack the gut's mucosal lining and produce bloody diarrhea
• E. coli strains produce toxins which increase fluid secretion. Enterohemorrhagic E. coli causes hemolytic uremic syndrome

History

• Abdominal cramps or gas
• Anorexia
• Bloating
• Fever
• Headache
• Loose or watery stools
• Nausea
• Pain during defecation
• Urgency to defecate
• Vomiting

Physical findings on examination

• Abdominal distension
• Abdominal tenderness (should be diffuse and should not be focal)
• Bloody stools are uncommon and indicate infection with a more pathogenic organism
• Dehydration (decreased skin turgor, depressed fontanel in infants, dry mucous membranes, hypotension, sunken eyes, prolonged capillary refill, tachycardia)
• Fever (usually low-grade)
• Increased bowel sounds

The diagnosis of traveler's diarrhea is mainly presumptive, based on the occurrence of diarrhea while visiting a high-risk region of the world. Mild cases do not require laboratory investigation, as they resolve within a few days without medication. However, severe cases can require antibiotic treatment and may depend on identification of the causative organism in order to select the appropriate antimicrobial therapy. Stool culture, and sometimes blood culture, can be useful.

Other laboratory test findings

• Fecal WBC: Occurrence of WBCs in fecal samples is suggestive of a bacterial etiology
• Stool examination: Presence of occult blood in stools suggests invasive pathogens, presence of ulcer, or other serious conditions
• Stool culture: Can be helpful in determination of the specific causative organism and antimicrobial sensitivity
• Stool Ova & Parasite examination: of stools may be indicated in cases where parasitic cause is suspected
• Stool for rotazyme may be useful in those with suspected rotavirus infection
• Stool for Norovirus ELISA or PCR may be useful when clinically indicated

• Amoebic dysentery
• C. difficile colitis
• Celiac disease
• Colon cancer
• Crohn's disease
• Drug-induced diarrhea
• Food poisoning
• Gastroenteritis
• Intestinal parasitic infection
• Irritable bowel syndrome
• Laxative abuse
• Malabsorption syndromes (fat or carbohydrate)
• Ulcerative colitis
• Other intra-abdominal infection or condition (abscess, appendicitis, diverticulitis, etc)

General treatment items

• Self treatment with anti-infective agents is often indicated in travellers
• Maintenance of adequate hydration, and rehydration is essential due to loss of water and electrolytes

Pharmacological treatment

• Antibiotics
  • 1st Line: Fluroquinolones (ciprofloxacin, norfloxacin, ofloxacin or levofloxacin) are drugs of choice
  • 2nd Line: Azithromycin is generally effective and is the drug of choice for pregnant women and children
  • 3rd Line: Rifaximin is useful as third-line therapy. It is not recommended for children 12 yrs
  • May use ceftriaxone 50 mg/kg IV daily (Max 1 gram) daily for 3 days
  • Trimethoprim/sulfamethoxazole and doxycycline are no longer recommended by the CDC due to pathogen resistance
• Anti-protozoal
  • Metronidazole: Useful for Giardia and Entamoeba infections
  • Nitazoxanide: Useful in cases of cryptosporidiosis and giardiasis
• Antimotility agents
  • Loperamide may be given along with antibiotics for reducing diarrhea; however, it should not be given in cases of bloody diarrhea and fever. It is not recommended in children 12 yrs
• Adjunctive agents
  • Bismuth subsalicylate may be useful in non-pregnant adults
  • Oral rehydration salts (ORS) are essential to counter dehydration and electrolyte losses, especially in infants and children

Medications indicated with specific doses

Antibiotics

• Azithromycin:
  • Adult Dosing
  • Peadiatrics Dosing
• Ciprofloxacin:
  • Adult Dosing
  • Peadiatrics Dosing
• Levofloxacin:
  • Adult Dosing
  • Peadiatrics Dosing
• Rifaximin:
  • Adult Dosing
  • Peadiatrics Dosing

Anti-protozoal

• Metronidazole
  • Adult Dosing
  • Peadiatrics Dosing
• Nitazoxanide
  • Adults Dosing
  • Pediatrics Dosing

Antimotility agents

• Loperamide: Antidiarrheal; inhibits peristalsis of intestines
  • Adult Dosing
  • Pediatrics Dosing (note that some recommend avoidance of these in children)

Adjunctive agents

• Bismuth subsalicylate
  • Adult Dosing
  • Peadiatrics Dosing

Dietary or Activity restrictions

• Adequate fluid intake to maintain urinary output at 1–2 mL/kg/hr, is important to avoid dehydration
• Food can be advanced as tolerated and desired. Initially small frequent consumption of fluids is indicated; but diet can be rapidly advanced if tolerated
• Bland diet (ie, devoid of spices) is recommended during recovery
• There is no evidence to support avoidance of lactose containing foods during gastroenteritis (American Academy of Pediatrics)

Monitoring

• Patients should be advised to follow recommended dietary restrictions during recovery
• Occasional loose stools that occur post treatment do not require further intervention
• If diarrhea persists along with fever and bloody stools, further medical intervention is required
• If dehydration occurs, medical intervention is required

Complications

• Antibiotic linked C. difficile infection
• Chronic carrier state (particularly salmonella)
• Chronic intestinal inflammation
• Dehydration
• Hemolytic uremic syndrome
• Irritable bowel syndrome
• Quinolone therapy may cause tendonitis (typically only with chronic use)
• Shock
• Temporary lactose intolerance

Prevention

• During travel, travelers must avoid consumption of uncooked or raw meat/fish/vegetables/milk products, unpeeled fruits/vegetables, tap water, food prepared by street vendors
• It is recommended to consume boiled/bottled water and well cooked or packaged food served hot
• Prophylaxis
  • Prophylaxis with antibiotics is not usually recommended except in cases of diplomats and the severely immunocompromised. Ciprofloxacin or rifaximin may be used
  • Bismuth subsalicylate has been shown to be significantly effective for prophylaxis
• Vaccination
  • Oral cholera vaccine containing killed whole V. cholerae O1 bacteria and the recombinant cholera toxin B subunit may provide short-term protection against enterotoxigenic E. coli (ETEC); however, the vaccine is not available in the U.S.
  • Vaccination is recommended for at-risk travelers, especially those who might be expected to have high exposure at their travel destination or who might be at significant personal risk in the event of fluid loss

Prognosis

• Traveler's diarrhea is usually not life-threatening, but can cause severe limitations to everyday activities
• This condition is self-limiting, typically lasting 3–5 days
• Most cases resolve without antibiotics

Pregnancy/pediatric effects on the condition

• Pregnant women have a higher risk of traveler's diarrhea due to decreased stomach acidity and increased GI transit time
• Quinolones are contraindicated during pregnancy, generally azithromycin is the antibiotic of choice

Synonyms

• Infectious diarrhea

ICD-9-CM

• 009.2 Infectious diarrhea
• 009.3 Diarrhea of presumed infectious origin

ICD-10-CM

• A09.0 Other and unspecified gastroenteritis of infectious origin

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