Review: chronic and persistent diarrhea with a focus in the returning traveler

Abstract

Background: Travelers' diarrhea is a common malady afflicting up to 50% of travelers after a 2-week travel period. An appreciable percentage of these cases will become persistent or chronic. We summarized the published literature reporting persistent/chronic diarrhea in travelers elucidating current understanding of disease incidence, etiology and regional variability.

Methods: We searched electronic databases (Medline, Embase, and Cochrane database of clinical trials) from 1990 to 2015 using the following terms: "chronic or persistent diarrh* and (returning) travel* or enteropathogen, GeoSentinel, and travel-associated infection. Included studies published in the English language on adult returning travelers (duration < 3-months) reporting denominator data. Point estimates and standard 95% confidence intervals were calculated for incidence using a random-effects model. Study incidence heterogeneity rates were assessed using x² heterogeneity statistics, graphically represented with Forest plots.

Results: We identified 19 studies meeting the inclusion criteria (all published after 1999). 18 studies reported upon the incidence of persistent/chronic diarrhea as a syndromic diagnosis in returning travelers; one study reported adequate denominator data from which to assess pathogen specific etiology. Giardiasis comprise an appreicaible percentage of infectious mediated persistent/chronic diarrhea in returning travelers. The overall estimate of persistent/chronic diarrhea incidence was 6% (0.05-0.07) in 321,454, travelers; with significant heterogeniety observed across regions. The total number of regional travelers, and point estimates for incidence (95% CI) for Latin American, African, and Asian travelers were [15816 (0.09 [0.07-0.11]), 42290 (0.06 [0.05-0.07]), and 27433 (0.07 [0.06-0.09])] respectively. We identified lower published rates of chronic diarrhea from Sub-Saharan Africa relative to [North Africa, South Central Asia, and Central America]. Persistent/chronic diarrhea ranked fourth as a syndromic diagnosis in all regions.

Conclusions: Persistent/Chronic diarrhea is a leading syndromic diagnosis in returning travelers across all regions. The 6% incidence [proportionate morbidity (PM) of 60] observed in over >300,000 global travelers is comparable to prior estimates. We identified lower published rates of chronic diarrhea from Sub-Saharan Africa relative to [North Africa, South Central Asia, and Central America]. Giardiasis comprises an appreciabile percentatge of travel-associated infectious mediated persistent/chronic diarrhea. There's a dearth of published data characterizing the incidence of specific enteropathogenic etiologies for persistent/chronic diarrhea in returning travelers.

Keywords: Chronic diarrhea; Enteropathogens; GeoSentinel surveillance; Giardiasis; Persistent diarrhea; Post-infectious irritable bowel syndrome; Travelers’ diarrhea.

Fig. 1

Flow Chart Depicting Search Methodology

Fig. 2

Forest Plot depicting point estimates (95% CI) for the incidence (PM) persistent/chronic diarrhea in Global Returning Travelers

Fig. 3

a-c Forest Plot depicting point estimates (95% CI) for the incidence (PM) persistent/chronic diarrhea in Returning Travelers Stratified by Continent (Latin America, Africa, and Asia)

Fig. 4

a-c Forest Plots depicting point estimates (95% CI) for the incidence (PM) persistent/chronic diarrhea in Returning Travelers Stratified by Continent (Latin America, Africa, and Asia) and Region