Infectious Diarrhea

Definition Of Diarrhea

 Increase in stool frequency or a decreased stool consistency  Usual stool fluid content: 10 ml/kg/d in an infant and > 200 g/d in the teenager and adult  Acute diarrhea- lasting less than 2 weeks

Acute Infectious Diarrhea

 Inflammatory -intestinal invasion - Cytotoxins (enhanced electrolyte secretion by the crypts)  Noninflammatory enterotoxin production -villous surface destruction

Approach to a Patient with Diarrhea

 Assess hydration status (PO intake, stool output, level of activity, UO.)  Prevent spread.

 Determine etiologic agent and provide specific therapy if indicated.

History

         Daycare attendance Recent travel Use of antibiotics Sick contacts Diet Duration and severity of diarrhea Stool consistency Presence of mucus and blood Other symptoms: fever, diarrhea

Food history

        Dairy- Campylobacter and Salmonella Eggs- Salmonella Meats- C. perfringens, Aeromonas, Campylobacter, Salmonella Ground beef- EHEC Poultry- Campylobacter Pork- Clostridium, Yersinia Seafood- Aeromonas, Plesiomonas, Vibrio Giardia, Cryptosporidium, Entamoeba- resistant to water chlorination (look for possible exposure to contaminated water)

Infectious causes of acute diarrhea in children



Viral

Rotavirus Calicivirus Astrovirus Parvovirus Pestivirus Adenovirus 

Bacterial

Campylobacter Salmonella E. coli Shigella Vibrio cholera Aeromonas hydrophiliia Yersinia enterocolitica Clostridium difficile



Parasitic

Giardia Entamoeba histolytica Cryptosporidium Isospora belli Strongyloides Trichuris trichuria Balantidium coli

Labs

   Fecal leukocytes (shows invasion, cytotoxin production) Stool O and P Stool culture

 Always culture stool for Salmonella, Shigella, Yersinia and Campylobacter in the presence of clinical signs of colitis or if fecal leucocytes are found.

Acute Diarrhea Special Considerations

Y Y N

fever, watery stool, gross blood

N N

Abrupt onset, frequent stools, no initial vomiting

Y

Methylene blue, stool exam PMN Giardia None Culture Shigella Salmonella Campylobacter Indicated Therapy

&

Rehydration Defined Approach

White blood cells in a stool sample (Methylene Blue Stain).

Bacteria Aeromonas Campylobacter Clostridium difficile ETEC EPEC EIEC Salmonella Shigella Vibrio TMP-SMX Erythromycin Metronidazole/ Vancomycin TMP- SMX TMP- SMX TMP- SMX Ampicillin or Chloramphenicol or TMP- SMX or Cefotaxime TMP- SMX, Ceftriaxone Tetracycline Indication Dysentery-like illness Early Moderate- severe disease Severe or prolonged Nursery epidemic, life threatening illness All cases Infants < 3 mns, immunodeficiency, typhoid fever ( S. typhi), bacteremia All cases All cases

References

Behrman R., R. Kliegman and H.Jenson. Nelson’s

Textbook of Pediatrics, 16

Saunders, pp 765-768.

th

ed. 2000, W.B.

DeWitt, T. Acute Diarrhea in Children. Pediatrics in Review. 1989; 11; 6-12 Huicho, Luis MD. Diagnostic Approach to

Acute Infectious Diarrhea: The State of the

Art. Bull. Inst. Fr. Etudes Andines. 1995, 24 (2): 317-339.

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 A.

A 2-yo girl has diarrhea and a temp of 38 viral, rather than a bacterial, enteritis?

◦ C. Which of the ff would suggest that she has Stool leukocytes B.

Mucus in stools C.

D.

E.

Blood in stools Vomiting before onset of diarrhea Frequent, mildly watery, small- volume stools