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Pathophys and Cause ⬇

Cause:Toxin-producing types like O157:H7 (Nejm 1995;333:364)

Pathophys:Colonic wall invasion and toxin production causes bloody mucus, like shigella

Epidemiology ⬆ ⬇

O157:H7 type (Ann IM 1995;123:698) in manure dust (Jama 2003;290:2709) in hamburger (Jama 1984;272:1349), cattle coats (petting zoo outbreak—Nejm 2002;347:555), sprouts (Ann IM 2001;135:239), drinking water, and swimming lakes (Nejm 1994;331:579). Most common cause of infectious bloody diarrhea in US

Signs and Symptoms ⬆ ⬇

Sx:Incubation period 1-3 d. Bloody mucus, fever in most, pain

Si:Low-grade fever, fecal leukocytes present, initial watery stool becomes bloody

Complications ⬆ ⬇

Hemolytic/uremic syndrome (in 10% vs 15%—Jama 1994;272:1349 vs. Nejm 2002;347:555) or TTP

r/o other gi infections (Diarrhea)

Lab and Xray ⬆ ⬇

Lab:Bact:Stool smear shows polys; if polys, culture for pathogens on sorbitol-MacConkey agar and do O157 antiserum test of cultured E. coli(Nejm 1995;333:364); stool toxin titers

Treatment ⬆

Rx:Rehydration and supportive care; at least in children, antibiotic rx increases risk of hemoytic uremic syndrome (Nejm 2000;342:1930), can use ciprofloxacin or Tm/S DS bid × 3 d (Ann IM 1987;106:216)