Travelers’ Diarrhea Paul Hladon, MD, DTM&H - - - - -

Travelers’ Diarrhea
Paul Hladon, MD, DTM&H
----Surgical Urgent Care & Emergency Services
Southern California Permanente Medical Group
Kaiser Permanente Medical Center
Panorama City, CA
Travelers’ Diarrhea
Paul Hladon, MD, DTM&H
----Surgical Urgent Care & Emergency Services
Southern California Permanente Medical Group
Kaiser Permanente Medical Center
Panorama City, CA
Leisure Reading
Common etiologies of travelers’
diarrhea (TD)
Basic pathophysiology of TD
Treatment for TD
Prophylaxis against TD
Prevention of food & waterborne illness
in travelers
Familiar to most travelers, esp. tropics
Most common travel-related health
problem – 25-50% of travelers
Bacteria (≥ 60%) most common cause
GI syndromes in tropics:
Watery diarrhea & gastroenteritis
Inflammatory diarrhea / dysentery
Persistent diarrhea > 2 weeks
Travelers’ diarrhea (TD)
What is TD?
Normal ecology of GI tract upset by
exposure to new foods & microorg.
Precise definition elusive
Three or more loose stools in 24hr plus
at least one sx of enteric disease:
Nausea, vomiting, cramps, fever, urgency,
tenesmus, bloody / mucoid stools
Mean duration of sx = 3-5 days w/o tx
Variable clinical course & severity
What is TD?
Majority of cases are self-limited &
5-15% of TD cases Æ dysentery, IV tx
These same 5-15% of pts tend to seek
medical consultation
Falciparum malaria?
Fever + diarrhea (14%)
Fever in returning travelers…
TD Risk
TD Risk
Regional differences in risk & etiology
Attack rates (median) same for Latin
America, Asia & Africa (54%)
Four- or five-star hotels NOT protective
against TD
Adventure travelers at higher risk than
hotel population in general
TD Risk
Travelers at risk:
Immunocompromised, children under 6
Low gastric acidity
Young adults, adventurers, “extreme” travelers
High socioeconomic status
No travel to tropics in 6 months
Travel from developed to underdeveloped area
Length of stay & “native” itinerary
Elderly, pregnancy, very young, immunocompromised, GI disease Æ
complications from TD
TD Etiology
ETEC = enterotoxigenic E. coli
Single most important pathogen worldwide
ETEC, Campylobacter jejuni & Shigella
spp. Æ 45% of identifiable pathogens
EAEC, Salmonella, Aeromonas, Plesiomonas,
V.cholerae, V. parahaemolyticus, V. vulnificus,
Yersinia, [Giardia & Cryptosporidium (3%)]
Norovirus, Norwalk virus (5-15%)
NO identifiable cause over ½ of cases
TD Etiology
Especially in Latin America, South Asia & Africa
E. coli
ETEC Æ 108 organisms required for
clinical illness – large inoculum
Poor sanitation, humans main reservoir
EAEC – emerging TD pathogen, 2nd
only to ETEC in some studies – LA
EIEC – dysentery sx, rare TD
EHEC – shiga-like toxin, HUS, TTP,
hemorrhagic colitis, O157:H7, rare TD
EPEC – infants in dev. world, rare TD
E. coli
ETEC – plasmids code for enterotoxins
Heat Stabile (ST) & Heat Labile (LT)
Pathogenic ETEC strains – one or both
ST – alters fluid transport in distal
small bowel, ↑ cGMP
LT – similar to cholera toxin, ↑ cAMP
Secretion of isotonic fluid, ↑ Clsecretion, ↓ Na+ absorption
Campylobacter infections – worldwide,
hyperendemic in tropics
Exposure to animals / food products
Developing countries – children, yearround, non-inflammatory, watery
Developed countries – age 15-29,
summer / fall, inflammatory, bloody
Adhere & invade epithelial cells Æ
cellular injury Æ diarrhea
Diarrhea, dysentery, death
100-200 organisms for dz.
Fly-borne, person-to-person
Human reservoir – epidemics
Cell invasion, lysis, ulceration in
terminal ileum & colon
Grossly bloody / mucoid stools,
tenesmus, painful straining,
crampy abdominal pain
Inflammation & ulceration of colonic
mucosa & intense proctitis
Rectal prolapse, toxic megacolon
HUS – hemolytic anemia, oliguric renal
failure & thrombocytopenia
Children & adults with dysentery
in tropics Æ Shigella infection
most likely
TD Etiology
Salmonella spp. – non-typhi infections
Vibrio spp. – seafood buffets
Cholera possible in travelers but rare
Viruses – adeno, astro, rota, calici –
cruise ship & hotel outbreaks
Protozoa – protracted diarrhea,
longer duration of stay
Giardia, Entamoeba, Cryptosporidium,
TD Pathophysiology
SMALL bowel
Large volume
Leukocytes (-)
LARGE bowel
Small volume
Leukocytes (+)
Shigella, Yersinia
TD Treatment
Most cases uncomplicated, self-limited,
respond to empiric tx
Most tx by travelers themselves
Educate travelers how to self-dx &
empirically tx TD when it occurs
Tx can often limit sx to one day
Bacterial diarrhea vs. toxic
gastroenteritis (food poisoning)
Protozoal diarrhea – long-term traveler
TD Treatment
Diagnostic work-up not always
necessary or cost-effective
Timely recognition of severe cases
Dysentery, profuse V/D, dehydration
Resistance of pathogens, geographic
region, invasive vs. non-invasive org.
Death in healthy travelers virtually
unheard of
TD Treatment
1) Rehydration
2) Symptomatic tx
3) Antibiotic tx
Oral rehydration solution (ORS) or
other fluids of choice
Some fluids contain excess sugar &
insufficient e-lytes compared to ORS
Anti-secretory, anti-motility & antiemetic medications
TD Treatment
Bismuth subsalicylate:
Anti-secretory, anti-inflammatory, anti-bacterial
Binds toxins of Vibrio & ETEC
Reduces intestinal secretions
524mg (2 tabs or 30mL) Q30 min x 8 doses
Reduces stool # & duration of illness by 50%
BLACK tongue & stools
*Decrease abx absorption – 6 hr window
ASA allergy, tinnitus?, warfarin
TD Treatment
Anti-motility agents: diphenoxylate +
atropine (Lomotil), loperamide
(Imodium) – maximum 8 tabs / 24 hr
Toilets Å medicate? Æ Itinerary
OK in cases of invasive diarrhea? Yes
Safe to take antibiotic & anti-motility
agent for dysentery
No adverse effects from one study
Recovery time faster with cipro + loperamide
TD Treatment
Bacterial TD (majority) Æ antibiotics
FQ or azithromycin (SE Asia)
Thailand: Campylobacter common &
resistance to FQ 70-90% Æ azithro
Cipro 500 mg bid x 1-3 days – other FQ
Azithro 1 gm PO single dose, children
10 mg/kg/day x 3 days
TMP/SMX? Only Mexico & Cent. Amer.
– high resistance rates worldwide
TD Treatment
Rifaximin (Xifaxan) – doesn’t cross
mucosa – unlikely to be effective in tx
dysentery / invasive organisms
Rifaximin non-formulary in KPHC
Tetracycline or doxycycline possible tx
Treatment with abx generally results in
recovery in 24-36 hrs
TD Treatment
Protozoal diarrhea – Central Asia
Giardia – tinidazole, metronidazole
Entamoeba (rare) – tinidazole,
diloxanide or paromomycin
Cyclospora – TMP/SMX
Dientamoeba fragilis – tetracycline
TD Prophylaxis
Behavior modification not reliably
effective, but prophylactic agents are
Risk of side effects & poor judgment –
adventurous eaters due to abx px
Good choice for travelers whose plans
would be ruined by TD – business,
honeymoon, short-term etc.
TD Prophylaxis
Bismuth subsalicylate – 2 tablets qid
Anti-microbial & anti-secretory agent, toxin
Protection ranges from 40-65%
Lowers bioavailability of doxycycline
TD Prophylaxis
Prophylactic antimicrobials
Neomycin, doxycycline, TMP/SMX have
all fallen out of favor Æ resistance
FQ – up to 84% protection
Rifaximin – 70-80% protection
Azithro good for tx of TD (SE Asia), but
no guidelines for prophylaxis
TD Prophylaxis
Bismuth SS
2 tabs
300 mg
400 mg
500 mg
500 mg
200 mg
Exclusive intra-luminal action
TD Prevention
PEEL it…
…or forget it ??????
Despite such measures, rate of TD in
travelers has not declined in 50 years
In one study, 34% of travelers still
contracted TD despite detailed
counseling & written instructions
TD Prevention
Probiotics – safe, but not recommended, modest benefit at best
Vaccines – oral cholera & typhoid risk
in travelers is low – no good vaccine
due to multiple organisms that can
cause TD
Behavioral modification regarding food
& beverages largely unsuccessful
TD Prevention
Carbonated drinks
Carbonated H2O
Boiled H2O
Purified H2O
Hot, grilled food
Processed food
Boiled food
Peeled fruits
Cooked veggies
Bottled H2O
Packaged ice
Dried foods
Jam, syrup
Washed vegs/fruit
Tap water
Chipped ice
Unpast. milk
Sauces, salsa
Raw seafood
Raw meats
Cold desserts
Unpeeled fruits
Local homes
Street vendors
Keystone, Jay S. et al. Travel Medicine: Expert Consult. Philadelphia, PA. Elsevier, Mosby, 2008, p.193.
TD Prevention
Food > H2O as contamination source
Drink only bottled or purified water,
even for brushing teeth or meds
Eat foods that are cooked & served
“piping” hot Æ 160*F, too hot to eat
Only eat fruits peeled by traveler
Avoid salads & leafy green vegetables
Avoid ice cubes in all beverages
TD Prevention
Drink only pasteurized milk
Avoid raw or undercooked seafood
Avoid food from street vendors
Dry off canned beverages – soda / beer
? Questions ?