travelers diarrhea review

JAMA had an excellent review (i think) of traveler's diarrhea (see travelers diarrhea jama 2015 in dropbox, or JAMA. 2015;313(1):71-80​). some of their major points for those traveling to high-risk countries:

--eating food from street vendors certainly increases the risk, though one can get it in a 5-star hotels (esp if food served buffet-style and food exposed to warm environmental conditions)

--average duration of the diarrhea is 4-5 days, though mean duration of incapacitation is <1 day. but passage of more than 10 stools/d is pretty uncommon (reported in 3% of cases)

--long-term complications can occur: postinfectious irritable bowel syndrome (PI-IBS) can occur in 3-17%, some without prior traveler's diarrhea, though PI-IBS tends to occur in those with more serious cases and esp in those infected with heat-labile toxin-producing enterotoxigenic e. coli

--there is a great table (their Table 2) of the regional differences in the etiology of traveler's diarrhea.  this is important to know to make sure therapy is appropriate -- eg, the incidence of campylobacter is much higher in south asia (15-25%) and southeast asia (25-35%), so azithro is a better antibiotic than a fluoroquinolone, to whict campylobacter is often resistant

--prevention: "boil it, cook it, peel it, or forget it". (though nothing is 100%: many cooked foods do not reach temperature of 100C, still most are safe at 60C, but some foods don't even reach that temperature). avoid ice.

    --bismuth subsalicylate provides modest protection (taking qid may decrease diarrhea 65%)

    --rifaximin (200mg 1-2x/d) also has modest effect (approx 48% in those going to south and southeast asia), though unclear if effective against invasive pathogens

    --prophylactic antibioltics (esp fluoroquinolones) are controversial because of developing resistance (and the poor little microbiome...), but might be used in those at very high risk of complications or those on short trips with important duties precluding time off for illness

--treatment (though depends on area of travel, as above). includes avoiding dehydration, plus: 

    ​--mild symptoms (1-3 loose stools/d): non-antibiotic -- bismuth subsalicylate 2 tabs or 1 oz liquid 4x/d,or loperamide 4mg initially, then 2mg after each unformed stool with max of 8mg/d. do not use loperamide wihtout antibiotics if T> 38.5C (or, i would add, systemic symptoms).

    --for moderate to severe diarrhea, antibiotics shorten course to about 1.5 days. in areas where cipro makes sense, give 500-750mg daily for 1-3 days; in south/southeast asia, azithro 500mg/dx3d or 1000 mg as single dose.

    ​--for noninvasive enteric bacteria (eg NOT assoc with fever or when shigella, campylobacter, or invasive salmonella are suspected), rifaximin 200mg tid for 3 days is not inferior to cipro.  can add loperamide with antibiotic for prompter improvement in symptoms

some of the guideline articles are a bit more quantitative for the treatment approaches: divide traveler's diarrhea into mild (1-2 loose stools/d without other symptoms), moderate (1-2 loose stools/d plus at least one symptom: nausea, vomiting, abdominal pain/cramping, fever, bloody stool), classic (>2 stools/d with at least one of those symptoms). for severe diarrhea (though not stressed in this article), i would suggest trying to get packets of oral rehydration solution which is available in pharmacies in most countries (put packet in clean drinking water), or you can make it up: add 1/2 tsp of salt, 1/2 tsp baking soda, and 4 tbsp sugar to 1 liter of clean water