The most important causes of traveler’s diarrhea occurring in developing regions, in decreasing order, are ETEC (heat-labile and heatstable toxin producing), enteroaggregative E coli, diffusely adherent Ecoli,noroviruses, rotavirus,Salmonellaspecies,Campylobacterjejuni, Shigella species, Aeromonas species, Plesiomonas shigelloides, enterotoxigenic Bacteroides fragilis, and Vibrio species; the parasites Giardia duodenalis, Cryptosporidium species, Entamoeba
histolytica, and Microsporidium species show regional importance