Traveller's diarrhoea

Intestinal protozoa in returning travellers: a GeoSentinel analysis from 2007 to 2019

BACKGROUND

Prolonged diarrhoea is common amongst returning travellers and is often caused by intestinal protozoa. However, the epidemiology of travel-associated illness caused by protozoal pathogens is not well described.

METHODS

We analysed records of returning international travellers with illness caused by Giardia duodenalis, Cryptosporidium spp., Cyclospora cayetanensis or Cystoisospora belli, reported to the GeoSentinel Network during January 2007-December 2019. We excluded records of travellers migrating, with an unascertainable exposure country, or from GeoSentinel sites that were not located in high-income countries.

RESULTS

There were 2517 cases, 82.3% giardiasis (n = 2072), 11.4% cryptosporidiosis (n = 287), 6.0% cyclosporiasis (n = 150) and 0.3% cystoisosporiasis (n = 8). Overall, most travellers were tourists (64.4%) on long trips (median durations: 18-30 days). Cryptosporidiosis more frequently affected people < 18 years (13.9%) and cyclosporiasis affected people ≥ 40 years (59.4%). Giardiasis was most frequently acquired in South Central Asia (45.8%) and sub-Saharan Africa (22.6%), cryptosporidiosis in sub-Saharan Africa (24.7%) and South-Central Asia (19.5%), cyclosporiasis in South East Asia (31.3%) and Central America (27.3%), and cystoisosporiasis in sub-Saharan Africa (62.5%). Cyclosporiasis cases were reported from countries of uncertain endemicity (e.g. Cambodia) or in countries with no previous evidence of this parasite (e.g. French Guiana). The time from symptom onset to presentation at a GeoSentinel site was the longest amongst travellers with giardiasis (median: 30 days). Over 14% of travellers with cryptosporidiosis were hospitalized.

CONCLUSIONS

This analysis provides new insights into the epidemiology and clinical significance of four intestinal protozoa that can cause morbidity in international travellers. These data might help optimize pretravel advice and post-travel management of patients with travel-associated prolonged gastrointestinal illnesses. This analysis reinforces the importance of international travel-related surveillance to identify sentinel cases and areas where protozoal infections might be undetected or underreported.

Investigating the influence of probiotics in preventing Traveler's diarrhea: Meta-analysis based systematic review

INTRODUCTION

Approximately 10-40 million travelers get Traveler's Diarrhea (TD) yearly. A significant decrease in TD incidence has not been achieved by depending solely on antibiotic prophylaxis and educational initiatives. Using prebiotics to prevent TD has also not been examined in previous evaluations of probiotics for TD, which failed to consider the strain-specificity of probiotic efficacy. This review investigates the overall effects of probiotics on preventing TD, including the impact of dosage, duration, and age.

METHODS

Standard literature databases were searched without restriction on publication year or language. The following criteria are included: randomized controlled trials (RCTs) in English or non-English unrestricted to publication year, excluding animal and observational studies. This systematic review applied the Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

RESULTS

Of the 166 screened papers, 10 RCTs were included. Lactobacillus acidophilus showed no efficacy in preventing TD except when mixed with other strains. Other genera of lactobacilli showed a protection rate of up to 39% against TD. Similarly, Saccharomyces cerevisiae and Saccharomyces boulardii have been effective in preventing TD.

CONCLUSION

Studies investigating probiotics as a preventive measure for TD remain limited. Only a few probiotics that reduce TD risk exist. Based on this systematic review and meta-analysis, specific probiotic strains, including L. acidophilus, L. rhamnosus, L. fermentum, S. cerevisiae, and S. boulardii, may prevent TD. The effect of additional probiotic strains on TD prevention must be further investigated.

Ferrous gluconate triggers ferroptosis in Escherichia coli: Implications of lipid peroxidation and DNA damage

Microbial ferroptosis has been proved to combat drug-resistant pathogens, but whether this pattern can be applied to the prevention and control of Escherichia coli remains to be further explored. In this study, ferrous gluconate (FeGlu) showed remarkable efficacy in killing E. coli MG1655 with a mortality rate exceeding 99.9%, as well as enterotoxigenic E. coli H10407 (ETEC H10407) and enterohemorrhagic E. coli O157:H7 (EHEC O157:H7). Bacteria death was instigated by the infiltration of Fe2+, accompanied by a burst of intracellular reactive oxygen species (ROS) and lipid peroxidation. Notably, mitigating lipid peroxidation failed to alleviate death of E. coli. Further findings confirmed that FeGlu induced DNA damage, and ΔrecA mutant showed more sensitive, implicating that DNA damage was involved in the death of E. coli. The direct interaction of Fe2+ with DNA was demonstrated by fluorescent staining, gel electrophoresis, and circular dichroism (CD). Moreover, proteomic analysis unveiled 50 differentially expressed proteins (DEPs), including 18 significantly down-regulated proteins and 32 significantly up-regulated proteins. Among them, the down-regulation of SOS-responsive transcriptional suppressor LexA indicated DNA damage induced severely by FeGlu. Furthermore, FeGlu influenced pathways such as fatty acid metabolism (FadB, FadE), iron-sulfur cluster assembly (IscA, IscU, YadR), iron binding, and DNA-binding transcription, along with α-linolenic acid metabolism, fatty acid degradation, and pyruvate metabolism. These pathways were related to FeGlu stress, including lipid peroxidation and DNA damage. In summary, FeGlu facilitated ferroptosis in E. coli through mechanisms involving lipid peroxidation and DNA damage, which presents a new strategy for the development of innovative antimicrobial strategies targeting E. coli infections.

Model-Based Estimation of Expected Time to Cholera Extinction in Lusaka, Zambia

The developing world has been facing a significant health issue due to cholera as an endemic communicable disease. Lusaka was Zambia's worst affected province, with 5414 reported cases of cholera during the outbreak from late October 2017 to May 12, 2018. To explore the epidemiological characteristics associated with the outbreak, we fitted weekly reported cholera cases with a compartmental disease model that incorporates two transmission routes, namely environment-to-human and human-to-human. Estimates of the basic reproduction number show that both transmission modes contributed almost equally during the first wave. In contrast, the environment-to-human transmission appears to be mostly dominating factor for the second wave. Our study finds that a massive abundance of environmental vibrio's with a huge reduction in water sanitation efficacy triggered the secondary wave. To estimate the expected time to extinction (ETE) of cholera, we formulate the stochastic version of our model and find that cholera can last up to 6.5-7 years in Lusaka if any further outbreak occurs at a later time. Results indicate that a considerable amount of attention is to be paid to sanitation and vaccination programs in order to reduce the severity of the disease and to eradicate cholera from the community in Lusaka.

A single dose of ciprofloxacin reduces the duration of diarrhea among service members deployed in Africa

OBJECTIVES

To assess the effectiveness of the adjunction of a one-gram single dose of ciprofloxacin to a symptomatic treatment for the early treatment of uncomplicated diarrhea during military operations of the French service members in Africa.

PATIENTS AND METHODS

This phase IV, multicentric, randomized, open-label, controlled trial was conducted in Chad, Mali, and in Central African Republic. A total of 267 French service members having at least one loose stool in the previous 24 hours were enrolled from May 2015 to June 2016. Participants were randomized to receive ciprofloxacin 1 g and a symptomatic treatment (racecadotril 100 mg three times a day and ad libidum oral rehydration solution) or a symptomatic treatment alone. The primary outcome was the duration of the diarrhea. Secondary outcomes were evaluated at the 72-hour endpoint and included recovery status, number of loose stools, frequency and duration of associated symptoms and safety of treatments.

RESULTS

Among 267 participants, 242 completed the trial. Participants receiving ciprofloxacin and a symptomatic treatment (n = 124) were significantly more likely to be cured at the endpoint than those who only received a symptomatic treatment (118): 94.4 % versus 74.6 % (OR = 5.7; 95 %CI: [2.4-13.6]; p < 10^-3). The antibiotic therapy reduced the average diarrhea duration by 30 % (p = 10^-4). Fever at inclusion was associated with a longer episode (HR = 0.61; 95 %CI: [0.41-0.89]; p = 0.012). No adverse event of medications was reported.

CONCLUSION

A single dose of ciprofloxacin was effective and safe in treating uncomplicated diarrhea among service members in Africa.

Outbreak of Cyclosporiasis in Korean Travelers Returning from Nepal

Cyclospora cayetanensis is an apicomplexan protozoan and is one of the most common pathogens causing chronic diarrhea worldwide. Eight stool samples with diarrheal symptom out of 18 Korean residents who traveled to Nepal were obtained, and examined for 25 enteropathogens including 16 bacterial species, 5 viral species, and 4 protozoans in stool samples as causative agents of water-borne and food-borne disease. Only C. cayetanensis was detected by nested PCR, and 3 PCR-positive samples were sequenced to confirm species identification. However, the oocysts of C. cayetanensis in fecal samples could not be detected by direct microscopy of the stained sample. As far as we know, this is the first report of a group infection with C. cayetanensis from a traveler visiting Nepal, and the second report of a traveler’s diarrhea by C. cayetanensis imported in Korea.

Lubeluzole: from anti-ischemic drug to preclinical antidiarrheal studies

BACKGROUND

Lubeluzole, a neuroprotective anti-ischemic drug, was tested for its ability to act as both antibiotic chemosensitizing and antipropulsive agent for the treatment of infectious diarrhea.

METHODS

In the present report, the effect of lubeluzole against antidiarrheal target was tested. The antimicrobial activity towards Gram-positive and Gram-negative bacteria was investigated together with its ability to affect ileum and colon contractility.

RESULTS

Concerning the antimicrobial activity, lubeluzole showed synergistic effects when used in combination with minocycline against four common Gram-positive and Gram-negative bacteria (Enterococcus faecalis ATCC 29212, Staphylococcus aureus ATCC 29213, Pseudomonas aeruginosa ATCC 27853, and Escherichia coli ATCC 25922), although relatively high doses of lubeluzole were required. In ex vivo experiments on sections of gut smooth muscles, lubeluzole reduced the intestinal contractility in a dose-dependent manner, with greater effects observed on colon than on ileum, and being more potent than reference compounds otilonium bromide and loperamide.

CONCLUSION

All above results identify lubeluzole as a possible starting compound for the development of a novel class of antibacterial adjuvants endowed with spasmolytic activity.

Travelers' Diarrhea: A Clinical Review

Background:

Travelers’ diarrhea is the most common travel-related malady. It affects millions of international travelers to developing countries annually and can significantly disrupt travel plans.

Objective:

To provide an update on the evaluation, diagnosis, treatment, and prevention of traveler’s diar-rhea.

Methods:

A PubMed search was completed in Clinical Queries using the key term “traveler’s diarrhea”. The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews. The search was restricted to English literature. Patents were searched using the key term “traveler’s diarrhea” from www.freepatentsonline.com.

Results:

Between 10% and 40% of travelers develop diarrhea. The attack rate is highest for travelers from a developed country who visit a developing country. Children are at particular risk. Travelers’ diarrhea is usually acquired through ingestion of food and water contaminated by feces. Most cases are due to a bac-terial pathogen, commonly, Escherichia coli, and occur within the first few days after arrival in a foreign country. Dehydration is the most common complication. Pretravel education on hygiene and on the safe selection of food items is important in minimizing episodes. For mild travelers’ diarrhea, the use of antibi-otic is not recommended. The use of bismuth subsalicylate or loperamide may be considered. For moder-ate travelers’ diarrhea, antibiotics such as fluoroquinolones, azithromycin, and rifaximin may be used. Loperamide may be considered as monotherapy or adjunctive therapy. For severe travelers’ diarrhea, antibiotics such as azithromycin, fluoroquinolones, and rifaximin should be used. Azithromycin can be used even for the treatment of dysentery whereas fluoroquinolones and rifaximin cannot be used for such purpose. Recent patents related to the management of travelers’ diarrhea are discussed.

Conclusion:

Although travelers’ diarrhea is usually self-limited, many travelers prefer expedient relief of diarrhea, especially when they are traveling for extended periods by air or ground. Judicious use of an antimotility agent and antimicrobial therapy reduces the duration and severity of diarrhea.

Family income and exposure to norovirus in childhood: Findings from the UK Millennium Cohort Study

Children from low income families are at greater risk of poorer health outcomes than their wealthier peers. Hospital admissions for children with gastroenteritis increase as deprivation increases. Noroviruses are responsible for 47-96% of outbreaks of acute paediatric gastroenteritis, and 5-36% of sporadic cases worldwide. However, evidence on the relationship between family income and childhood exposure to norovirus is still limited, with published studies pointing to conflicting results. This study explored the relationship between family income and early childhood exposure to norovirus in the United Kingdom using data from the Millennium Cohort Study linked to serological data. Exposure to norovirus was measured by the level of human norovirus-specific antibodies (titres) obtained from oral fluid samples collected from 5962 pre-school age UK children and tested for Norovirus-specific Immunoglobulin G (IgG). Multivariable linear and quantile regression analyses were conducted to investigate the extent to which family income was associated with child norovirus exposure, and to explore the potential mechanisms through which income might translate into norovirus exposure. Higher norovirus-specific IgG titres were associated with higher family income, but the relationship weakened after controlling for potential mediating factors, mainly increased opportunities for person-to-person contacts, such as formal childcare arrangements. This study provides novel evidence that can help inform and prioritise policy interventions (e.g. vaccination) and health promotion programmes to reduce child health inequalities in the area of gastrointestinal infections.

Nonthermal control of Escherichia coli growth using extremely low frequency electromagnetic (ELF-EM) waves

BACKGROUND

Escherichia coli (E. coli) bacteria normally live in the intestines of people and animals. Most E. coli are harmless and the treatment of the infection could be achieved by using antibiotics, however the effectiveness is still debatable and needs more investigation.

OBJECTIVE

Researching the inhibition resonance frequency of square amplitude modulating waves (QAMW) that can inhibit the growth activity of E. coli and its ability to make division.

METHODS

A range of different extremely low frequencies of square amplitude modulated waves (QAMW) from 0.1 to 1.0 Hz from two generators with a constant carrier frequency of 10 MHz, amplitude of 10 Vpp, modulating depth ± 2 Vpp and constant field strength 200 V/m were used to treat E. coli cells at 37 °C.

RESULTS

The exposure of E. coli to 0.3 Hz QAMW for 90 min was the most inhibited frequency where the bacterial growth inhibited by 42.3%. Furthermore, a significant increase in antibiotic susceptibility to protein and cell wall inhibitors was investigated. Also, results of the chromosomal DNA sequences, dielectric relaxation and TEM indicated highly significant molecular and morphological changes after the exposure.

CONCLUSIONS

We concluded that the exposure of E. coli to QAMW at the inhibiting frequency interfered with the bioelectric signals generated from the bacteria during the cell division and changed the cellular activity and DNA sequences, and these changes lead to a significant inhibition of the bacterial growth. This is a new promising technique that aids to avoid the repetitive use of antibiotics against the bacterial pathogens.

Travelers' diarrhea: update on the incidence, etiology and risk in military and similar populations - 1990-2005 versus 2005-2015, does a decade make a difference?

BACKGROUND

Travelers' diarrhea remains a prevalent illness impacting individuals visiting developing countries, however most studies have focused on this disease in the context of short term travel. This study aims to determine the regional estimates of travelers' diarrhea incidence, pathogen-specific prevalence, and describe the morbidity associated with diarrheal disease among deployed military personnel and similar long term travelers.

METHODS

We updated a prior systematic review to include publications between January 1990 and June 2015. Point estimates and confidence intervals of travelers' diarrhea and pathogen prevalence were combined in a random effects model and assessed for heterogeneity. Eighty-two studies were included in the analysis, including 29 new studies since the prior systematic review.

RESULTS

Military personnel were evaluated in 69% of studies and non-military long term travelers in 34%, with a median duration of travel of 4.9 months, and travel predominantly to the Middle East, Southeast Asia, and Latin America and the Caribbean. Sixty-two percent of tested cases were due to bacterial pathogens, with enterotoxigenic E. coli (ETEC), enteroaggregative E. coli (EAEC), and Campylobacter predominating, and significant regional variability. The incidence of TD from studies with longitudinal data was 36.3 cases per 100 person-months, with the highest rates in Southeast Asia, Latin America and the Caribbean, and the Middle East, with higher estimates from those studies using self-reporting of disease. Morbidity remained significant, with 21% being incapacitated or placed sick in quarters (SIQ) by their illness, 15% requiring intravenous fluids, and 3% requiring hospitalization.

CONCLUSIONS

In comparison to results from the prior systematic review, there were no significant differences in incidence, pathogen prevalence, or morbidity; however there was a trend toward improved care-seeking by sick individuals.

Prevalence and Antimicrobial Susceptibility Profile of Salmonella Serovars Isolated from Slaughtered Cattle in Addis Ababa, Ethiopia

Salmonella is one of the top causes of foodborne bacterial illnesses in humans. The primary sources of human Salmonella infection are food producing animals such as cattle, poultry, and swine. A cross-sectional study was undertaken to estimate the prevalence and to determine the serovar distribution and antimicrobial susceptibility profiles of Salmonella spp. isolated from fecal (n=567) and carcass swab (n=159) samples of slaughtered cattle at Addis Ababa Abattoir Enterprise and Kara'alo PLC, Abattoirs, in Addis Ababa, Ethiopia between January 2014 and April 2015. Salmonella isolation was conducted according to Global Foodborne Infections Network Laboratory Protocol and isolates were confirmed by genus specific PCR and serotyped by slide agglutination test. Susceptibility of the isolates to 17 antimicrobials was testedusing the Kirby-Bauer disk diffusion method according to the guidelines of the Clinical and Laboratory Standards Institute. Out of the total 726 samples examined, 27 (3.7%) were positive for Salmonella. Salmonella was detected in 4.1% (23/567) fecal and 2.5% (4/159) carcass swab samples. Twelve different serovars were identified and the most predominant serovars were S. Dublin (n=10, 35.7%) and S. Virchow (n=5, 17.9%), followed by S. Braendrerup, S. Haifa, and S. Saintpaul which were isolated from 2 samples each (7.1%). All of the Salmonella isolates investigated were resistant or intermediately resistant to four or more of the 17 drugs tested. High resistance rate was recorded to streptomycin 25 (89.3%), cephalothin 20 (71.4%), ampicillin 19 (67.9%), and amoxicillin+clavulanic acid 19 (67.9%). Resistance to five or more antimicrobials was detected in 20 (71.5%) of the isolates. Multidrug resistance to more than 7 antimicrobials was detected in 5 (17.9%) of the isolates. Isolation of such multidrug resistant strains of Salmonella from slaughtered cattle poses a major public health concern. These findings imply the need for a strict biosecurity and regulation of antimicrobial use across the country.

Management of Acute Diarrheal Illness During Deployment: A Deployment Health Guideline and Expert Panel Report

BACKGROUND

Acute diarrheal illness during deployment causes significant morbidity and loss of duty days. Effective and timely treatment is needed to reduce individual, unit, and health system performance impacts.

METHODS

This critical appraisal of the literature, as part of the development of expert consensus guidelines, asked several key questions related to self-care and healthcare-seeking behavior, antibiotics for self-treatment of travelers' diarrhea, what antibiotics/regimens should be considered for treatment of acute watery diarrhea and febrile diarrhea and/or dysentery, and when and what laboratory diagnostics should be used to support management of deployment-related travelers' diarrhea. Studies of acute diarrhea management in military and other travelers were assessed for relevance and quality. On the basis of this critical appraisal, guideline recommendations were developed and graded by the Expert Panel using good standards in clinical guideline development methodology.

RESULTS

New definitions for defining the severity of diarrhea during deployment were established. A total of 13 graded recommendations on the topics of prophylaxis, therapy and diagnosis, and follow-up were developed. In addition, four non-graded consensus-based statements were adopted.

CONCLUSIONS

Successful management of acute diarrheal illness during deployment requires action at the provider, population, and commander levels. Strong evidence supports that single-dose antimicrobial therapy is effective in most cases of moderate to severe acute diarrheal illness during deployment. Further studies are needed to address gaps in available knowledge regarding optimal therapies for treatment, prevention, and laboratory testing of acute diarrheal illness.

Control of Virulence Gene Expression by the Master Regulator, CfaD, in the Prototypical Enterotoxigenic Escherichia coli Strain, H10407

Enterotoxigenic Escherichia coli (ETEC) is the most common bacterial cause of diarrhea in children in developing countries, as well as in travelers to these countries. To cause disease, ETEC needs to produce a series of virulence proteins including enterotoxins, colonization factors and secretion pathways, which enable this pathogen to colonize the human small intestine and deliver enterotoxins to epithelial cells. Previously, a number of studies have demonstrated that CfaD, an AraC-like transcriptional regulator, plays a key role in virulence gene expression by ETEC. In this study, we carried out a transcriptomic analysis of ETEC strain, H10407, grown under different conditions, and determined the complete set of genes that are regulated by CfaD. In this way, we identified a number of new target genes, including rnr-1, rnr-2, etpBAC, agn43, flu, traM and ETEC_3214, whose expression is strongly activated by CfaD. Using promoter-lacZ reporters, primer extension and electrophoretic mobility shift assays, we characterized the CfaD-mediated activation of several selected target promoters. We also showed that the gut-associated environmental signal, sodium bicarbonate, stimulates CfaD-mediated upregulation of its virulence target operons. Finally, we screened a commercial small molecule library and identified a compound (CH-1) that specifically inhibited the regulatory function of CfaD, and by 2-D analoging, we identified a second inhibitor (CH-2) with greater potency.

Guidelines for the prevention and treatment of travelers' diarrhea: a graded expert panel report

BACKGROUND

: Travelers' diarrhea causes significant morbidity including some sequelae, lost travel time and opportunity cost to both travelers and countries receiving travelers. Effective prevention and treatment are needed to reduce these negative impacts.

METHODS

: This critical appraisal of the literature and expert consensus guideline development effort asked several key questions related to antibiotic and non-antibiotic prophylaxis and treatment, utility of available diagnostics, impact of multi-drug resistant (MDR) colonization associated with travel and travelers' diarrhea, and how our understanding of the gastrointestinal microbiome should influence current practice and future research. Studies related to these key clinical areas were assessed for relevance and quality. Based on this critical appraisal, guidelines were developed and voted on using current standards for clinical guideline development methodology.

RESULTS

: New definitions for severity of travelers' diarrhea were developed. A total of 20 graded recommendations on the topics of prophylaxis, diagnosis, therapy and follow-up were developed. In addition, three non-graded consensus-based statements were adopted.

CONCLUSIONS

: Prevention and treatment of travelers' diarrhea requires action at the provider, traveler and research community levels. Strong evidence supports the effectiveness of antimicrobial therapy in most cases of moderate to severe travelers' diarrhea, while either increasing intake of fluids only or loperamide or bismuth subsalicylate may suffice for most cases of mild diarrhea. Further studies are needed to address knowledge gaps regarding optimal therapies, the individual, community and global health risks of MDR acquisition, manipulation of the microbiome in prevention and treatment and the utility of laboratory testing in returning travelers with persistent diarrhea.

[Consensus paper treatment of acute traveler's diarrhea. Practice recommendation for travel advice]

BACKGROUND

In times of mass tourism, traveler's diarrhea is one of the most common health problems of long-distance travel. Globally, some 40 million cases occur annually. Travellers to risk areas should therefore be comprehensively advised beforehand, as to what action to take in case of an acute traveler's diarrhea and what drugs to add to their first-aid kit. To date none, or hardly any specific studies or valid specific guidelines for the treatment of traveler's diarrhea are available for Germany.

METHOD

Drafting a consensus paper based on results of a specialists' meeting to evaluate therapeutic options in the treatment of acute uncomplicated travelers' diarrhea. The foundation for the present consensus recommendations is current evidence on antidiarrheals available in Germany for symptomatic treatment of gastrointestinal infections, summarized in the S2k guideline for gastrointestinal infections and Whipple's disease. Further taken into account for the present consensus recommendations were Pubmed-listed publications on symptomatic treatment of traveler's diarrhea, practical aspects, and the experts' experience in travel medicine.

RESULTS AND CONCLUSION

For the treatment of acute uncomplicated traveler's diarrhea - more than 90 % of all cases - the secretion inhibitor racecadotril is considered first choice, based on our evaluation criteria. The previously usual practice of recommending the antimotility drug loperamide as first choice should be reconsidered, in favor of the recent active ingredient racecadotril. Antibiotics should be used only in complicated cases. A large number of travelers who generally demand antibiotic therapy should be disabused of their expectations. Other therapeutic measures that are currently available for the treatment of acute diarrhea while traveling play a subordinate role.

Efficacy of water treatment processes and endemic gastrointestinal illness - A multi-city study in Sweden

Outbreaks of acute gastrointestinal illnesses (AGI) have been linked to insufficient drinking water treatment on numerous occasions in the industrialized world, but it is largely unknown to what extent public drinking water influences the endemic level of AGI. This paper aimed to examine endemic AGI and the relationship with pathogen elimination efficacy in public drinking water treatment processes. For this reason, time series data of all telephone calls to the Swedish National Healthcare Guide between November 2007 and February 2014 from twenty Swedish cities were obtained. Calls concerning vomiting, diarrhea or abdominal pain (AGI calls) were separated from other concerns (non-AGI calls). Information on which type of microbial barriers each drinking water treatment plant in these cities have been used were obtained, together with the barriers' theoretical pathogen log reduction efficacy. The total log reduction in the drinking water plants varied between 0.0 and 6.1 units for viruses, 0.0-14.6 units for bacteria and 0.0-7.3 units regarding protozoans. To achieve one general efficacy parameter for each plant, a weighted mean value of the log reductions (WLR) was calculated, with the weights based on how commonly these pathogen groups cause AGI. The WLR in the plants varied between 0.0 and 6.4 units. The effect of different pathogen elimination efficacy on levels of AGI calls relative non-AGI calls was evaluated in regression models, controlling for long term trends, population size, age distribution, and climatological area. Populations receiving drinking water produced with higher total log reduction was associated with a lower relative number of AGI calls. In overall, AGI calls decreased by 4% (OR = 0.96, CI: 0.96-0.97) for each unit increase in the WLR. The findings apply to both groundwater and surface water study sites, but are particularly evident among surface water sites during seasons when viruses are the main cause of AGI. This study proposes that the endemic level of gastroenteritis can indeed be reduced with more advanced treatment processes at many municipal drinking water treatment plants.

Manipulation of the Microbiota Using Probiotics

A number of diseases are associated with alterations in the composition of the microbiota of various niches of the human body. Although, in most cases, it is unclear if these alterations are the cause or the consequence of disease, they provide a rationale for therapeutic or prophylactic manipulation of a dysbiotic microbiota. Approaches to manipulate the microbiome include administration of either live bacteria, which are underrepresented in the diseased individual, substances that aim at increasing the populations of these bacteria, or a combination of the two. This chapter summarizes the available data in therapeutic manipulation of a various diseased states including irritable bowel syndrome, inflammatory bowel disease, necrotizing enterocolitis, atopic and allergic diseases, and antibiotic-associated and infectious diarrhoea.

Detection of enterotoxigenic E. coli in hospitalised children with and without diarrhoea in Blantyre, Malawi

BACKGROUND

Enterotoxigenic E. coli (ETEC) is an important cause of diarrhoea among children in developing countries. The burden of ETEC infection was investigated for the first time in children in Malawi.

METHODS

Faecal samples obtained from children < 5 years of age hospitalised with diarrhoea in Blantyre, Malawi over a 10-year period (1997-2007) before introduction of the rotavirus vaccine were examined by PCR for ETEC heat-labile (LT) and heat-stable (STh and STp) enterotoxins. Children hospitalised without diarrhoea were enrolled over a 2-year period as a comparison group.

RESULTS

ETEC was detected in 205 (10.6%) of 1941 children with diarrhoea. The most prevalent toxin type was STh (6·6%), followed by LT (2·1%) and STp (0·9%). ETEC infection was most prevalent in infants aged 6-11 months. Co-infection with rotavirus was common. ETEC was detected in 37 (7·3%) of 507 children without diarrhoea.

CONCLUSION

The burden of ETEC infection in young Malawian children is substantial and should become a focus of diarrhoea prevention efforts in the post-rotavirus vaccine era.

Prevention of travelers’ diarrhea in adults

Travellers’ diarrhoea is defined as a set of signs and symptoms caused by an acute gastrointestinal tract infection that affect people travelling outside their place of residence (usually abroad to the countries of lower hygiene standards, especially to the tropics and the subtropical regions). Africa, Central and South America as well as Asia are the highest-risk destinations. Travellers’ diarrhoea is believed to be the most frequent travel-related health problem. Despite of the fact that this is usually a mild and self-limiting medical condition, it may interfere with the individual defined travel-related objectives, for example relaxation or business. The aim of this review is to present the basic preventive methods of travellers’ diarrhoea in generally healthy adults such as adherence to hygiene recommendations, chemoprevention and vaccinations.

Traveler's Diarrhea in Foreign Travelers in Southeast Asia: A Cross-Sectional Survey Study in Bangkok, Thailand

The effect of origin and destination country on traveler's diarrhea incidence rates in Southeast Asia is poorly understood, and research generally only addresses diarrhea in travelers from the developed world. This study evaluated the attack rate and effects of traveler's diarrhea by origin and destination and analyzed key risk factors. A self-administered questionnaire was provided to foreign travelers departing Southeast Asia from Suvarnabhumi Airport, Bangkok, Thailand. It evaluated traveler demographics, relevant knowledge and practices, experiences of diarrhea, and the details and consequences of each diarrheal episode. A total of 7,963 questionnaires were completed between April 2010 and July 2011. Respondents were 56% male (mean age 35) with a mean and median duration of stay of 28 days and 10 days, respectively. Most respondents were from Europe (36.8%) or East Asia (33.4%). The attack rate of traveler's diarrhea was 16.1%, with an incidence rate of 32.05 per 100 person months. Travelers' origin and destination countries significantly related to diarrhea risk. Oceanians had the highest risk (32.9%) and East Asians the lowest (2.6%). Vietnam and Indonesia were the highest risk destinations (19.3%). Other significant factors were youth, trip duration, number of countries visited, and frequently drinking beverages with ice.

Management of traveller's diarrhoea with a combination of sodium butyrate, organic acids, and A-300 silicon dioxide

Introduction

Traveller's diarrhoea (TD), defined by UNICEF/WHO as three or more unformed stools with or without other symptoms, imposes a considerable burden on travellers from developed countries. Various efforts have focused on decreasing the prevalence and severity of this condition.

Aim

To assess the efficacy of a combination of sodium butyrate, organic acids, and A-300 silicon dioxide in treatment providing symptomatic relief of TD.

Material and methods

The study was conducted in accordance with a protocol presented to the Bioethical committee of Poznan University of Medical Sciences. A total of 278 patients travelling to countries with higher risk of diarrhoea for at least 10 days were divided into a study arm being administered, in case of TD, a combination of sodium butyrate, organic acids, and A-300 silicon dioxide (n = 139) and a placebo arm (n = 139) with placebo administration.

Results

Forty-seven patients completed the study (22 in the study arm and 25 in the placebo arm). The diarrhoea occurrence after initiation of treatment at first symptoms was significantly lower in the study arm as compared to the placebo arm (9% vs. 36%, p = 0.041). Also, subjects from the study arm more frequently reported that the regimen administered had been efficient for their symptoms in comparison to the placebo arm (72.7% vs. 32%, p = 0.008). No adverse effects of the administered medication were noted during the study.

Conclusions

Sodium butyrate, organic acids, and A-300 silicon dioxide can be successful in decreasing symptoms of TD. Because of its efficacy and lack of observed side effects it has a strong potential in the treatment of patients with TD.

Escherichia coli in Europe: an overview

Escherichia coli remains one of the most frequent causes of several common bacterial infections in humans and animals. E. coli is the prominent cause of enteritis, urinary tract infection, septicaemia and other clinical infections, such as neonatal meningitis. E. coli is also prominently associated with diarrhoea in pet and farm animals. The therapeutic treatment of E. coli infections is threatened by the emergence of antimicrobial resistance. The prevalence of multidrug-resistant E. coli strains is increasing worldwide principally due to the spread of mobile genetic elements, such as plasmids. The rise of multidrug-resistant strains of E. coli also occurs in Europe. Therefore, the spread of resistance in E. coli is an increasing public health concern in European countries. This paper summarizes the current status of E. coli strains clinically relevant in European countries. Furthermore, therapeutic interventions and strategies to prevent and control infections are presented and discussed. The article also provides an overview of the current knowledge concerning promising alternative therapies against E. coli diseases.

Effectiveness of the WC/rBS oral cholera vaccine in the prevention of traveler's diarrhea: a prospective cohort study

OBJECTIVE

Traveler's diarrhea (TD) is the most frequent disease among people from industrialized countries who travel to less developed ones, especially sub-Saharan Africa, Southern Asia and South America. The most common bacteria causing TD is enterotoxigenic Escherichia coli (ETEC). The WC/rBS cholera vaccine (Dukoral) has been shown to induce cross-protection against ETEC by means of the B subunit of the cholera toxin. The aim of the study was to evaluate the effectiveness of the WC/rBS cholera vaccine in preventing TD.

METHODS

Between May 1 and September 30 (2007), people seeking pre-travel advice in ten Spanish international vaccination centers were included in a prospective cohort study of travelers to cholera risk countries. The incidence rates of TD were adjusted for variables whose frequencies were statistically different (entry point 0.10) between the vaccinated and non-vaccinated cohorts.

FINDINGS

The vaccinated cohort (n = 544 travelers) included people vaccinated with the WC/rBS cholera vaccine, and the non-vaccinated cohort (n = 530 travelers) by people not vaccinated. The cumulative incidence rate of TD was 1.69 in vaccinated and 2.14 in non-vaccinated subjects. The adjusted relative risk of TD in vaccinated travelers was 0.72 (95% CI: 0.58-0.88) and the adjusted vaccination effectiveness was 28% (95% CI: 12-42).

CONCLUSIONS

The WC/rBS cholera vaccine prevents TD in 2 out of 7 travelers (preventive fraction: 28%). The number needed to vaccinate (NNV) to prevent 1 case of TD is 10.

Traveler's Diarrhea

Travelers' diarrhea (TD) is the most important health issue among international travelers. In high risk areas, 50-90% of travelers may experience an episode of TD. The risk of acquiring TD is influenced by factors such as the destination, duration of stay, standard of accommodation, type of travel, age of the traveler, and also by individual risk factors. Most cases of TD are caused by bacteria; treatment for TD are loperamide and antibiotics. Preventive strategies such as hygiene measures have limited impact. Prophylactic intake of antibiotics or vaccines to prevent from TD can be considered in special situations.

Characterization of a novel EAST-negative enteropathogenic E. coli strain implicated in a food-borne outbreak of diarrhoea in adults

Enteropathogenic Escherichia coli (EPEC) is usually associated with outbreaks and sporadic cases of severe infantile diarrhoea in the developing world, and less commonly with sporadic cases in developed countries. Very little evidence indicates that EPEC is a food-borne pathogen for adults. In a previous study, two groups of adult travellers became ill, and eae(+) E. coli of serogroup O111 was isolated from affected individuals and epidemiologically linked to food consumption. Here the strain responsible was further investigated and characterized as an unusual atypical EPEC. PCR analysis of the designated type isolate showed the presence of the rorf1 and espB genes of the LEE pathogenicity island, which was inserted at the chromosomal selC locus. The isolate was negative for the enteroaggregative E. coli EAST-1 toxin present in other strains of EPEC associated with food-borne outbreaks. The strain adhered sparsely to HEp-2 cell monolayers in a diffuse manner, but fluorescent actin staining demonstrated that it was capable of inducing polymerization of actin at the sites of bacterial attachment. Strain P2583 is the first EAST-negative EPEC to be confirmed as a cause of outbreaks of infection in adults following the consumption of contaminated food or water.

Travel-associated enteric infections diagnosed after return to the United States, Foodborne Diseases Active Surveillance Network (FoodNet), 2004-2009

BACKGROUND

Approximately 40% of US travelers to less developed countries experience diarrheal illness. Using data from the Foodborne Diseases Active Surveillance Network (FoodNet), we describe travel-associated enteric infections during 2004-2009, characterizing the patients, pathogens, and destinations involved.

METHODS

FoodNet conducts active surveillance at 10 US sites for laboratory-confirmed infections with 9 pathogens transmitted commonly through food. Travel-associated infections are infections diagnosed in the United States but likely acquired abroad based on a pathogen-specific time window between return from international travel to diagnosis. We compare the demographic, clinical, and exposure-related characteristics of travelers with those of nontravelers and estimate the risk of travel-associated infections by destination, using US Department of Commerce data.

RESULTS

Of 64,039 enteric infections reported to FoodNet with information about travel, 8270 (13%) were travel associated. The pathogens identified most commonly in travelers were Campylobacter (42%), nontyphoidal Salmonella (32%), and Shigella (13%). The most common travel destinations were Mexico, India, Peru, Dominican Republic, and Jamaica. Most travel-associated infections occurred in travelers returning from Latin America and the Caribbean (LAC). Risk was greatest after travel to Africa (75.9 cases per 100,000 population), followed by Asia (22.7 cases per 100,000), and LAC (20.0 cases per 100,000).

CONCLUSIONS

The Latin America and Caribbean region accounts for most travel-associated enteric infections diagnosed in the United States, although travel to Africa carries the greatest risk. Although FoodNet surveillance does not cover enterotoxigenic Escherichia coli, a common travel-associated infection, this information about other key enteric pathogens can be used by travelers and clinicians in pre- and posttravel consultations.

Shigella flexneri bacteremia in two immune-competent adult travelers

Shigella bacteremias are uncommon in immune-competent adults. We report two cases of Shigella flexneri bacteremia that occurred in healthy young travelers, who recovered. Self-medication with loperamide and ibuprofen without antibiotics (case 1) and concomitant falciparum malaria (case 2) were the only co-morbidities found in our two patients.

A cluster of acute diarrhea suspected to be cholera in French travelers in Haiti, December 2010

A cluster of 21 cases of watery diarrhea suspected to be cholera that involved French military policemen and young volunteers occurring in the context of the Haiti cholera outbreak is described. The attack rate (AR) was higher among young volunteers (71.4%) than among policemen (15.3%) (p < 0.0001). There was a significant association between raw vegetables consumption and watery diarrhea in the young volunteer group. If we consider the raw vegetables consumers only, AR was lower among doxycycline-exposed subjects (relative risk: 0.2; 95% confidence interval: 0.1-0.4). The main aspect that is of scientific interest is the potential prophylactic effect of doxycycline used for malaria prophylaxis on the watery diarrhea AR.

Directed evaluation of enterotoxigenic Escherichia coli autotransporter proteins as putative vaccine candidates

Background

Enterotoxigenic Escherichia coli (ETEC) is a major diarrheal pathogen in developing countries, where it accounts for millions of infections and hundreds of thousands of deaths annually. While vaccine development to prevent diarrheal illness due to ETEC is feasible, extensive effort is needed to identify conserved antigenic targets. Pathogenic Escherichia coli, including ETEC, use the autotransporter (AT) secretion mechanism to export virulence factors. AT proteins are comprised of a highly conserved carboxy terminal outer membrane beta barrel and a surface-exposed amino terminal passenger domain. Recent immunoproteomic studies suggesting that multiple autotransporter passenger domains are recognized during ETEC infection prompted the present studies.

Methodology

Available ETEC genomes were examined to identify AT coding sequences present in pathogenic isolates, but not in the commensal E. coli HS strain. Passenger domains of the corresponding autotransporters were cloned and expressed as recombinant antigens, and the immune response to these proteins was then examined using convalescent sera from patients and experimentally infected mice.

Principal Findings

Potential AT genes shared by ETEC strains, but absent in the E. coli commensal HS strain were identified. Recombinant passenger domains derived from autotransporters, including Ag43 and an AT designated pAT, were recognized by antibodies from mice following intestinal challenge with H10407, and both Ag43 and pAT were identified on the surface of ETEC by flow cytometry. Likewise, convalescent sera from patients with ETEC diarrhea recognized Ag43 and pAT, suggesting that these proteins are expressed during both experimental and naturally occurring ETEC infections and that they are immunogenic. Vaccination of mice with recombinant passenger domains from either pAT or Ag43 afforded protection against intestinal colonization with ETEC.

Conclusions

Passenger domains of conserved autotransporter proteins could contribute to protective immune responses that develop following infection with ETEC, and these antigens consequently represent potential targets to explore in vaccine development.

Diarrheal diseases are responsible for more than 1.5 million deaths annually in developing countries. Enterotoxigenic E. coli (ETEC) are among the most common bacterial causes of diarrhea, accounting for an estimated 300,000–500,000 deaths each year, mostly in young children. There unfortunately is not yet a vaccine that can offer sustained, broad-based protection against ETEC. While most vaccine development effort has focused on plasmid-encoded finger-like ETEC adhesin structures known as colonization factors, additional effort is needed to identify conserved target antigens. Epidemiologic studies suggest that immune responses to uncharacterized, chromosomally encoded antigens could contribute to protection resulting from repeated infections. Earlier studies of immune responses to ETEC infection had identified a class of surface-expressed molecules known as autotransporters (AT). Therefore, available ETEC genome sequences were examined to identify conserved ETEC autotransporters not shared by the commensal E. coli HS strain, followed by studies of the immune response to these antigens, and tests of their utility as vaccine components. Two chromosomally encoded ATs, identified in ETEC, but not in HS, were found to be immunogenic and protective in an animal model, suggesting that conserved AT molecules contribute to protective immune responses that follow natural ETEC infection and offering new potential targets for vaccines.

Inconvenience due to travelers' diarrhea: a prospective follow-up study

BACKGROUND

Limited data exist documenting the degree to which travelers are inconvenienced by travelers' diarrhea (TD). We performed a prospective follow-up study at the travel clinic of Leiden University Medical Center in The Netherlands to determine the degree of inconvenience and to determine how experiencing TD affects travelers' perception.

METHODS

Healthy adults who intended to travel to the (sub)tropics for less than two months were invited to take part. Participants filled out a web-based questionnaire before departure and after returning home. TD was defined as three or more unformed stools during a 24-hour period.

RESULTS

390 of 776 Eligible travelers completed both questionnaires. Participants' median age was 31 years and mean travel duration 23 days. Of 160 travelers who contracted TD (incidence proportion 41%, median duration of TD episode 2.5 days) the majority (107/160, 67%) could conduct their activity program as planned despite having diarrhea. However, 21% (33/160) were forced to alter their program and an additional 13% (20/160) were confined to their accommodation for one or more daylight days; 53 travelers (33%) used loperamide and 14 (9%) an antibiotic. Eight travelers (5%) consulted a physician for the diarrheal illness. When asked about the degree of inconvenience brought on by the diarrheal illness, 39% categorized it as minor or none at all, 34% as moderate and 27% as large or severe. In those who regarded the episode of TD a major inconvenience, severity of symptoms was greater and use of treatment and necessity to alter the activity program were more common. Travelers who contracted travelers' diarrhea considered it less of a problem in retrospect than they had thought it would be before departure.

CONCLUSION

Conventional definitions of TD encompass many mild cases of TD (in our study at least a third of all cases) for which treatment is unlikely to provide a significant health benefit. By measuring the degree of inconvenience brought on by TD, researchers and policy makers may be able to better distinguish 'significant TD' from mild TD, thus allowing for a more precise estimation of the size of the target population for vaccination or stand-by antibiotic prescription and of the benefit of such measures.

Incidence, risk factors and treatment of diarrhoea among Dutch travellers: reasons not to routinely prescribe antibiotics

Background

Travellers' diarrhoea (TD) is the most common infectious disease among travellers. In the Netherlands, stand-by or prophylactic antibiotics are not routinely prescribed to travellers. This study prospectively assessed the incidence rate, risk factors, and treatment of TD among immunocompetent travellers.

Methods

Persons who attended the travel clinic of the Public Health Service Amsterdam in 2006-2007 before short-term travel to tropical and subtropical countries were invited to answer a questionnaire regarding sociodemographics and travel purpose; they were also asked to keep a daily structured travel diary, recording their itinerary, symptoms, and self-medication or consultation with a doctor. Diarrhoea episodes containing blood or mucous were considered severe.

Results

Of 1202 travellers, the median age was 38 years, and the median travel duration 3 weeks. Of all episodes, 96% were mild. The median duration of TD was 2 days and significantly shorter in subsequent episodes compared to first episodes (p < 0.0005). Of first episodes 38% started in the first travel week. The incidence rate (IR) for first episodes was 2.49 (95% confidence interval [CI], 2.30-2.70) per 100 travel days, with the highest IR among travellers to South-Central and West Asia. The IR for first and subsequent episodes was comparable. Risk factors for first episodes included female sex, a Western country of birth, and tourism as the purpose of travel. The lowest risk was in travellers to South America. An independent risk factor for subsequent episodes was female sex. In total, 5% of travellers used antibiotics; of those, 92% had mild diarrhoea, and 53% received antibiotics over the counter.

Conclusions

TD is common among travellers, but the overall course is mild, not requiring treatment. The incidence rates for first and second episodes are comparable. Female sex is a risk factor for the first episode, as well as subsequent ones. Prescription antibiotics are not needed in short-term healthy travellers.

Management of the returning traveler with diarrhea

Traveler's diarrhea (TD) strikes 20-60% of travelers visiting developing countries. It occurs shortly after the return and can be distinguished into two categories: acute and persistent TD. Acute TD, mostly caused by bacterial and viral pathogens, is usually mild and self-limited, and deserves empirical symptomatic and/or antibiotic therapy in selected cases. Fluoroquinolones are progressively superseded in this indication by azithromycin, a well tolerated macrolide active against most bacteria responsible for TD, including the quinolone-resistant species of Campylobacter jejuni that are now pervasive, especially in Southeast Asia and India. Persistent TD in the returning traveler is much rarer than its acute counterpart and may be associated with three types of causes. Persistent infections, among which Giardia and possibly Entamoeba predominate, account for a significant proportion of cases. Postinfectious processes represent a second cause and comprise temporary lactose malabsorption and postinfectious irritable bowel syndrome, now considered a major cause of persistent TD. Finally, apparently unrelated chronic diseases causing diarrhea are occasionally unmasked by TD and represent a third type of persistent TD, among which the well established case of incident inflammatory bowel disease poses intriguing pathogenesis questions. This review discusses recent advances in the field and provides practical recommendations for the management of TD in adult, immunocompetent returning travelers.

Salmonella infections associated with international travel: a Foodborne Diseases Active Surveillance Network (FoodNet) study

Salmonella species cause an estimated 1.2 million infections per year in the United States, making it one of the most commonly reported enteric pathogens. In addition, Salmonella is an important cause of travel-associated diarrhea and enteric fever, a systemic illness commonly associated with Salmonella serotypes Typhi and Paratyphi A. We reviewed cases of Salmonella infection reported to the Centers for Disease Control and Prevention's (CDC) Foodborne Diseases Active Surveillance Network (FoodNet), a sentinel surveillance network, from 2004 to 2008. We compared travelers with Salmonella infection to nontravelers with Salmonella infection with respect to demographics, clinical characteristics, and serotypes. Among 23,712 case-patients with known travel status, 11% had traveled internationally in the 7 days before illness. Travelers with Salmonella infection tended to be older (median age, 30 years) than nontravelers (median age, 24 years; p<0.0001), but were similar with respect to gender. The most common destinations reported were Mexico (38% of travel-associated infections), India (9%), Jamaica (7%), the Dominican Republic (4%), China (3%), and the Bahamas (2%). The proportions of travelers with Salmonella infection hospitalized and with invasive disease were inversely related to the income level of the destination (p<0.0001). The most commonly reported serotypes, regardless of travel status, were Enteritidis (19% of cases), Typhimurium (14%), Newport (9%), and Javiana (5%). Among infections caused by these four serotypes, 22%, 6%, 5%, and 4%, respectively, were associated with travel. A high index of clinical suspicion for Salmonella infection is appropriate when evaluating recent travelers, especially those who visited Africa, Asia, or Latin America.

Incidence and impact of travelers' diarrhea among foreign backpackers in Southeast Asia: a result from Khao San road, Bangkok

BACKGROUND

Travelers' diarrhea is the most common disease reported among travelers visiting developing countries, including Southeast Asia, a region visited by large numbers of backpackers each year. Currently, the knowledge of travelers' diarrhea among this group is limited. This study aimed to determine the incidence and impact of travelers' diarrhea in this group.

METHOD

Foreign backpackers in Khao San road, Bangkok, Thailand, were invited to fill out a study questionnaire, in which they were queried about their demographic background, travel characteristics, pretravel preparations and actual practices related to the risk of travelers' diarrhea. For backpackers who had experienced diarrhea, the details and impact of each diarrheal episode were also assessed.

RESULTS

In the period April to May 2009, 404 completed questionnaires were collected and analyzed. Sixty percent of participants were male; overall, the median age was 26 years. Nearly all backpackers (96.8%) came from developed countries. Their main reason for travel was tourism (88%). The median stay was 30 days. More than half of the backpackers (56%) carried some antidiarrheal medication. Antimotility drugs were the most common medications carried by backpackers, followed by oral rehydration salts (ORS), and antibiotics. Their practices were far from ideal; 93.9% had bought food from street vendors, 92.5% had drunk beverages with ice-cubes, and 33.8% had eaten leftover food from a previous meal. In this study, 30.7% (124/404) of backpackers had experienced diarrhea during their trip. Most diarrhea cases (88%) were mild and recovered spontaneously. However, 8.8% of cases required a visit to a doctor, and 3.2% needed hospitalization. Longer duration of stay and drinking beverages with ice-cubes were associated with higher risk of diarrhea.

CONCLUSIONS

About one third of the foreign backpackers in Southeast Asia had experienced diarrhea during their trip. Their current practices related to the risk of travelers' diarrhea were inadequate and should be improved.