Originally published at Pediatric EM Morsels on November 8, 2017. Reposted with permission.

Follow Dr. Sean M. Fox on twitter @PedEMMorsels

Diarrhea is no joking matter (although it can be the butt of many jokes – see what I did there?). It causes a large burden to patients (ex, dehydration), care providers, and the healthcare system. Fortunately, more often than not, it is a self-limited process that requires focusing on maintaining hydration status.  There are occasions, however, that may spur one on toward considering antibiotic administration for that “infectious diarrhea.”  Recently, the Infectious Disease Society of America (IDSA) published guidelines related specifically to this.  So, let’s take a brief moment to review their recommendations on management of Infectious Diarrhea:

Infectious Diarrhea: Basics

• Infectious diarrhea inflicts the greatest burden on regions with inadequate sanitation and hygiene.

• Classification of diarrhea by duration:
  • Acute – < 7 days
  • Prolonged – 7-13 days
  • Persistent – 14-29 days
  • Chronic – 30+ days

• Many infectious agents are very “potent” (i.e., transmitted via low inocula).
• Since vaccination for Rotavirus, Norovirus now is the leading cause of hospitalization due to gastroenteritis.
• Most common bacterial pathogens:
  • Salmonella enterica – leading bacterial cause of hospitalization due to gastroenteritis
  • Campylobacter
  • Shigella
  • Yersinia
  • E. coli O157

• Some post-infectious complications to consider:
  • Erythema Nodosum
  • Glomerulonephritis
  • Guillain-Barre Syndrome (related to Campylobacter)
  • Hemolytic Uremic Syndrome
  • Hemolytic Anemia
  • Reactive Arthritis
  • Meningitis
  • Ekiri Syndrome (toxic encephalopathy +/- seizure)

Infectious Diarrhea: IDSA Takeaway Points

The IDSA document is rather thorough, but here are some of the useful takeaway points that can help us in the acute care environments. [Shane, 2017]

• Historic points can help find patients at higher risk for infectious diarrhea in developed countries:
  • Hospitalization and Long-term care facilities
  • Animal exposure (ex, Petting Zoo)
  • Child care facilities exposure
  • International travel
  • Immunocompromised hosts
  • Antimicrobial exposures (ex, C. Diff)

• Fever and/or Bloody diarrhea should catch your attention for possible enteropathogens:
  • Travel to endemic areas and/or consumption of foods prepared by people with recent endemic exposure increase risk.
  • Enteropathogens may present in similar clinical fashion, but can differ in their management!
    • Shigella and Campylobacter may benefit from antimicrobials.
    • Salmonella and Shiga Toxin producing E. Coli (STEC) do not!
      • When concern for Shiga Toxin producing organisms, distinguishing between Shiga toxin 1 and Shiga toxin 2 (which is more potent) is useful.
      • Considering HUS in these cases is important.
        • Look for pallor and/or petechiae!
        • Look for renal dysfunction, thrombocytopenia, or anemia.

• Stool studies can help determine appropriate management.
  • Stool cultures and Shiga toxin assays are recommended when fever/bloody diarrhea is present.
    • Obviously, stool culture results won’t guide initial management, but can affect follow-up care.
    • Negative stool cultures can also raise concern for other etiologies, like Inflammatory Bowel Disease.
  • Fecal leukocyte and stool lactoferrin detection should NOT be used to establish the cause of acute infectious diarrhea.

• Blood cultures should be obtained for:
  • Infants < 3 months of age
  • Signs of septicemia
  • Immunocompromised patients
  • Patients with high risk for hemolytic anemia

• Diagnostic testing is NOT recommended in most cases of uncomplicated traveler’s diarrhea.
  • Those with diarrhea >13 days may need evaluation for parasitic infections.
  • C.Diff and Inflammatory Bowel Disease should also be considered with persistent diarrhea.

• Empiric Therapy:
  • In immunocompetent patients, empiric antibiotics  while awaiting culture results are NOT recommended.
  • Close family contacts that are asymptomatic do not need empiric therapy.
  • Avoid antibiotics for people infected with STEC O157 and other Shiga toxin 2 producing organisms.
  • Empiric therapy is recommended for:
    • Ill appearing patients with documented fever and bacillary dysentery (frequent, scant bloody stools with abdominal cramping and tenesmus – presumptively due to Shigella).
    • Patients who recently travelled internationally with temp >38.5C and signs of sepsis.
    • Immunocompromised patients with severe illness and bloody diarrhea.
  • Empiric therapy for children:
    • 3rd Generation cephalosporin for infants <3 months of age and others with neurologic involvement
    • Azithromycin is also an option based on local resistance patterns.

• Initial management should always focus on rehydration.
  • Probiotics can help.
  • Antimotility agents should NOT be used in children.

Moral of the Morsel:

• Most children do NOT need empiric antibiotics for acute diarrhea.
• Stool Culture can be helpful, particularly in the setting of bloody diarrhea, but antibiotics can usually wait for results as many pathogens do not benefit from antibiotics.
• Keep your Ddx open!

References