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 fever, watery stool, gross blood Abrupt onset, frequent stools, no initial vomiting Methylene blue, stool exam PMN Giardia None Culture Shigella Salmonella Campylobacter Indicated Therapy Rehydration Defined Approach Y N N Y N Y &

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

Antibiotic Treatment BacteriaAntibioticIndication AeromonasTMP-SMXDysentery-like illness CampylobacterErythromycinEarly Clostridium difficileMetronidazole/ Vancomycin Moderate- severe disease ETECTMP- SMXSevere or prolonged EPECTMP- SMXNursery epidemic, life- threatening illness EIECTMP- SMXAll cases SalmonellaAmpicillin or Chloramphenicol or TMP- SMX or Cefotaxime Infants < 3 mns, immunodeficiency, typhoid fever ( S. typhi), bacteremia ShigellaTMP- SMX, Ceftriaxone All cases VibrioTetracyclineAll cases

References Behrman R., R. Kliegman and H.Jenson. Nelson’s Textbook of Pediatrics, 16 th ed. 2000, W.B. Saunders, pp 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):

A 2-yo girl has diarrhea and a temp of 38 ◦ C. Which of the ff would suggest that she has viral, rather than a bacterial, enteritis? A. Stool leukocytes B. Mucus in stools C. Blood in stools D. Vomiting before onset of diarrhea E. Frequent, mildly watery, small- volume stools