Diarrhea:  Causative Organisms
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þ Traveler's Diarrhea/Acute Outpatient Diarrhea
 - about 80% bacterial
 - Enterotoxigenic E. coli:  in Mexico
 - Enteroinvasive E. coli
  + O157:H7--found in GI tract of ruminants, found in runoff from farms
  + bloody diarrhea
  + 95% will recover without Rx
  + some will go on to systemic illness, including hemolytic-uremic syndrome
  + increased risk of hemolytic-uremic syndrome from giving antibiotics from
    one strong study, though meta-analysis showed this not to be likely.
    Despite this, still OK to give empiric antibiotics to adults with bad
    diarrhea, but not to infants or small kids with bloody diarrhea, or those
    likely to have E. coli O157:H7: instead, culture (ask specifically for the
    O157:H7 culture)
 - Campylobacter (dogs, primates)
 - Shigella (quinolones are agents of choice [Gotuzzo E, Oberhelman RA,
     Maguina C, et al. Comparison of single-dose treatment with norfloxacin
     and standard 5-day treatment with trimethoprim-sulfamethoxasole for acute
     shigellosis in adults. Antimicrob Agents Chemother 1992; 33:1101.
     Bennish ML, Salam MA, Haider R, et al. Therapy for shigellosis: II.
     Randomized, double-blind comparison of ciprofloxaxin and ampicillin. J
     Infect Dis 1990; 164:338.])
 - Salmonella (found in pet turtles, endemic in poultry and eggs in U.S.;
     CAM resistant)
   + typhoid = enteric fever:
    - Diarrhea
    - stepwise fever elevation over 4-5 days
    - sore throa
    - a rash of raised, discrete, irregular pink blanching macules (Rose spots)
      on the anterior chest wall
    - bradycardia out of proportion to the fever
   + nontyphoidal
   (N.B.: quinolones will shorten disease and shedding, though relapses common,
     so treatment not routinely recommended. [Reid TMS. The treatment of
     non-typhic salmonellosis. J Antimicrob Chemother 1992; 29:4.])
 - Vibrio spp.
 - Yersinia enterocoltica
 - Entamoeba histolytica (rural Asia, colonic irrigation clinics)
 - Dientomoeba fragilis (day care)
 - Giardia lamblia (everywhere; day care) (EIA test now available; highly
   specific, and more sensitive than O+P; done once a day M-F at Mercy)
 - Strongyloides worms (chronic diarrhea)
 - Gay bowel syndrome

þ Other diarrhea
 - Cryptosporidium (1-2 wks in normal host; from livestock, e.g., veterinarians;
   also day care; requires absolute 1-micron filter; Giardia filters not
   adequate)
 - Rotavirus (day care centers)
 - Norwalk agent (more in adults, probably in seafood)
 - E. Coli O157-H7:  causes bloody diarrhea, hemorrhagic colitis, and
   hemolytic-uremic syndrome
 - Pleisiomonas
 - Aeromonas
 - C. difficile
Blastocystis hominis:  not a pathogen per Shlim's study.

þ Cyclospora:
  <Cyclospr.TXT>