View source for Traveler's diarrhea pathophysiology

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{{Traveler's diarrhea}}
==Overview==
==Pathophysiology==
*The transmission and pathogenesis of traveler's diarrhea is dependent on the infectious agent. 
*The following table summarizes the natural reservoir, transmission, and pathogenesis of common infectious agents associated with traveler's diarrhea:

{| {{table}}
| align="center" style="background:#f0f0f0;"|'''Infectious Agent'''
| align="center" style="background:#f0f0f0;"|'''Characteristics'''
| align="center" style="background:#f0f0f0;"|'''Reservoir'''
| align="center" style="background:#f0f0f0;"|'''Common Mode of Transmission'''
| align="center" style="background:#f0f0f0;"|'''Pathogenesis'''
|-
| [[Ecoli enteritis|''E. coli'' (ETEC)]]
|
*Gram-negative rod
|
*Humans and animals
|
*Fecal-oral route
*Contaminated ground beef, unpasteurized mild, cheese, vegetables, or water
|
*Enterotoxin-mediated: secretion of heat-labile toxin (LT) and heat-stable toxin (ST)
|-
| [[Campylobacter jejuni|''Campylobacter jejuni'']]
|
*Gram-negative rod
|
*Humans and animals
*Fecal-oral route
*Contaminated meat, unpasteurized mild, cheese, vegetables, or water
*Exposure to infected animals
|
*Enterotoxin-mediated: secretion of cholera-like enterotoxin
|-
| [[Shigellosis|''Shigella'' spp.]]||
|
*Gram-negative rod
|
*Humans only
|
*Fecal-oral route
*Contaminated meat and pork, unpasteurized mild, cheese, vegetables, or water
|
*Low inoculum sufficient for infection (resistant to gastric acid)
*Enterotoxin-mediated: secretion of Shiga toxin
*Invasion of macrophages and induction of cellular apoptosis
*Intracellular spread by actin polymerization processes (rocket propulsion)
|-
| [[Salmonellosis|''Salmonella'' spp.]]||
|
*Gram-negative rod
|
*''S. typhi'': Humans only
*Other ''Salmonella'' spp.: Humans and animals
|
*Fecal-oral route
*Contaminated raw egg shells, poultry, unpasteurized mild, cheese, vegetables, or water
|
*High inoculum sufficient for infection (inactivated by gastric acid)
*Vi capsule endotoxin prevents opsonization and lysis
*Spread through the reticuloendothelial system
|-
| [[Norovirus infection|Norovirus]]
|
*Positive-sense, single-stranded RNA virus
|
*Humans and animals
|
*Fecal-oral route
*Contaminated food, vegetables, and water
*Fomites
|
*Aerosol exposure
*Virus uses P2 subdomain for binding and HBGA for attachment on host cell
|-
| [[Rotavirus infection|Rotavirus]]
*Double-stranded RNA virus
|
*Humans and animals
*Fecal-oral route
*Fomites
|
*Poorly understood pathogenesis
*Viral replication in villous epithelium of host small intestine
|-
| [[Giardiasis|Giardia lamblia]]
*Anerobic, flagellated protozoan parasite
|
*Humans and animals
|
*Ingestion of cysts in water or uncooked foods
*Fecal-oral route
|
*Attaches to the epithelium by a ventral adhesive disc, and reproduces via binary fission
*Usually luminal infection, no hematogenous spread
|-
| [[Amebiasis|''Entamoeba histolytica'']]
|
*Anaerobic parasitic protozoan with pseudopods
|
*Humans
*Rare (but present) in animals
|
*Ingestion of cysts in water
*Fecal-oral route
|
*Excystation in the small intestine and migration to the large intestine
*Luminal and extraluminal infection, hematogenous spread common
|-
| Cryptosporidium
|
*Spore-forming parasite
|
*Humans and animals
|
*Ingestion of oocytes in water
*Fecal-oral route
|
*Minimally invasive, surface-level mucosal inflammation
*Usually luminal infection, potential to infect biliary tree
|}

== References ==
{{reflist|2}}
{{WH}}
{{WS}}


[[Category:Gastroenterology]]
[[Category:Foodborne illnesses]]
[[Category:Water-borne diseases]]
[[Category:Infectious disease]]
[[Category:Emergency medicine]]
[[Category:Disease]]