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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.

Background: Enterotoxigenic Escherichia coli (ETEC) is a major cause of travellers' diarrhoea. We investigated the efficacy and safety of a skin-patch vaccine containing the pathogen's heat-labile toxin (LT) in a population of travellers to Mexico and Guatemala., Methods: In this phase 3, randomised, double-blind, placebo-controlled field trial, healthy adults (aged 18-64 years) travelling from Germany or the UK to Mexico or Guatemala were assigned in a 1:1 ratio by a dynamic electronic randomisation system to receive transcutaneous immunisation with a patch containing 37.5 μg of ETEC LT or a placebo patch. Participants, site staff, and the investigators who did the analyses were masked to group assignment. Participants were vaccinated before travel, with two patches given 14 days apart. In the destination country, participants tracked stool output in a diary and provided stool samples for pathogen identification if diarrhoea occurred. The primary endpoint was the proportion of participants with at least one episode of moderate-to-severe diarrhoea (defined as four or more unformed stools in a 24 h period) in which either or both ETEC enterotoxins (LT and heat-stable toxin [ST]) were detected. The study is registered at ClinicalTrials.gov, number NCT00993681., Findings: 2036 participants were recruited and randomly assigned between Oct 14, 2009, and Aug 13, 2010, with 1016 allocated to receive the LT patch and 1020 the placebo patch. 821 participants in the LT-patch group and 823 in the placebo group received both vaccinations and were analysed in the per-protocol population. 30 (3.7%, 95% CI 2.5-5.2) participants in the LT-patch group and 46 (5.6%, 4.1-7.4) in the placebo group had moderate or severe ETEC diarrhoea (vaccine efficacy 34.6%, -2.2 to 58.9; p=0.0621). 9333 local (ie, patch-site) adverse events (including erythema, rash, pruritus, hyperpigmentation, pain, hypopigmentation, and oedema) occurred in 943 (93%) of 1015 participants in the LT-patch group, compared with 1444 local adverse events in 574 (56%) of 1019 participants in the placebo group (p<0.0001). Serious adverse events occurred in 25 participants (14 in the LT-patch group and 11 in the placebo group), with all regarded as either unrelated or possibly related to treatment. Vaccine-induced hyperpigmentation persisted for at least 180 days after vaccination in 150 (18%) of the 849 participants who received both vaccinations and returned for final assessment in the LT-patch group, compared with none of the 842 participants in the placebo group. The vaccine was immunogenic, with a post-vaccination geometric mean titre of LT-specific serum immunoglobulin G of 3400.29, compared with 315.41 in the placebo group., Interpretation: Although the LT antigen was delivered effectively by the skin patch, the vaccine did not protect travellers against diarrhoea caused by ETEC or other organisms. Future vaccines against travellers' diarrhoea might need to include several antigens against various diarrhoeal pathogens, and might need to be able to generate mucosal and higher systemic immunity., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Background: A patch vaccine containing heat-labile toxin (LT) from enterotoxigenic Escherichia coli (ETEC) has demonstrated to be beneficial in reducing the rate and severity of travelers' diarrhea in Latin America. To evaluate the efficacy of this transdermal vaccine system in an area with a different diarrheal pathogen profile, an additional phase 2 study was conducted in European travelers to India., Methods: For this multicenter, randomized, double-blinded, placebo-controlled field study 723 subjects were recruited; 603 (299 LT vaccine, 304 placebo) were included in the per-protocol-population (PPP)., Results: Although the LT patch induced a measurable LT immune response in recipients, it failed to protect against LT ETEC or all-cause diarrhea. In the PPP the incidence rate of diarrhea as per primary endpoint was 6.0% (18 of 299) in the vaccine group and 5.9% (18 of 304) in the placebo group. Additionally, lower than expected rates of LT ETEC diarrheas were observed in India. The vaccine delivery system frequently produced rash and pruritus at the site of application, long term hyperpigmentation persisted in a minority of LT recipients, and also few site reactions were noted in the placebo group., Conclusions: The evaluated patch vaccine failed to satisfy mainly with respect to protective efficacy. Noninvasive prophylactic agents against travelers' diarrhea, particularly vaccines against the most frequent pathogens, thus continue to be badly needed., (© 2013 International Society of Travel Medicine.)

Background: A survey was designed to assess travelers' willingness to take antibiotic chemoprophylaxis against travelers' diarrhea (TD) or to intervene with antibiotic or symptomatic treatments., Methods: A brief written questionnaire was administered to clients in North American (United States and Canadian) and European (UK and German) travel clinic waiting rooms to assess length, purpose, and destination of their upcoming trips; their perceived risk of developing TD at their destination; and their preferences for hypothetical treatment or chemoprophylaxis options, which included descriptions, but no mention of brand names, of a systemically absorbed antibiotic based on a fluoroquinolone, a nonabsorbed antibiotic based on rifaximin, and an over-the-counter antidiarrheal similar to loperamide., Results: The 209 UK and German travelers planned significantly longer travel than the 277 US and Canadian travelers (25 vs 15 d, p < 0.001) and correctly recognized high risk of TD more often than the North Americans (81% vs 61%, p < 0.001). More of the North Americans preferred any therapy options compared with the Europeans; only 14% of the North Americans preferred no treatment compared with 29% of the Europeans (p < 0.001). More of the North Americans and the Europeans preferred the nonabsorbed antibiotic than the systemically absorbed antibiotic, regardless of if combined with the antidiarrheal agent. Significantly more of the Europeans preferred not to take antibiotic chemoprophylaxis than North Americans (66% vs 37%, p < 0.001). Among the North Americans, significantly more travelers preferred chemoprophylaxis with the nonabsorbed than the systemic antibiotic (45% vs 33%, p= 0.003)., Conclusions: Among the relatively small groups of travelers studied, the UK and German travelers were more cognizant of TD risk than US and Canadian travelers. The Europeans were less inclined to take chemoprophylaxis or treatment. Both groups preferred treatment or prophylaxis with the nonabsorbed antibiotic over the systemically absorbed antibiotic or the antidiarrheal agent.

There is currently only one vaccine available that provides protection against diarrhea caused by Vibrio cholerae and, to a lesser degree, enterotoxigenic Escherichia coli (ETEC). Adverse events of this oral whole-cell/recombinant B-subunit vaccine have been negligible. Protective efficacy against cholera is 85%, while protection against the heat-labile toxin of ETEC reaches 67%. There is still a need for data on protection of Western travelers against travelers' diarrhea in general by Dukoral vaccination. However, current studies show a protective effect of up to 43%. Although the vaccine is only licensed for vaccination against cholera in most Western countries, there is mounting evidence that the oral cholera vaccine is a valuable option to those traveling to high-risk endemic areas. Vaccination against cholera and ETEC should be recommended for at-risk travelers, in particular those with high exposure at their travel destination or high personal risks through fluid loss.

In patients returning from an endemic region who present with a feverish illness, malaria should always be the first disease you should suspect and investigate. In the case of uncomplicated traveler's diarrhea in the adult in contrast, unspecific symptomatic treatment suffices, and no specific diagnostic work-up is required. Only when certain alarm symptoms are present are further measures such as the search for pathogens or chemotherapy indicated.

Background: Traveling to tropical regions is related to increased health risks. Travelers' diarrhea is the most frequent health problem, but the range of travel-related diseases also includes potential life-threatening diseases such as malaria. The actual risk of European travelers acquiring specific infectious diseases and other hazards in the tropics is to a large extent unknown and is therefore often adopted from that of the indigenous population. The objective of this study was to elucidate the risk for travel-related diseases, symptoms, and accidents in a population of Europeans who travel to popular tourist destinations., Methods: From July 2003 to June 2004, 794 travelers consulting the travel clinic of the Berlin Institute of Tropical Medicine were recruited for a questionnaire-based observational study before traveling to Kenya, Tanzania, Senegal, the Gambia, India, Nepal, Thailand, or Brazil., Results: Overall, illness was reported by 42.9% of travelers, with 10.2% reporting more than one adverse health event. Most frequently gastrointestinal symptoms were noted (34.6%), followed by respiratory symptoms (13.7%). More than 5% experienced an accident. Travel to the Indian subcontinent nearly doubled the risk of becoming ill; travel to Thailand significantly decreased the risk. Additional risk factors were a long duration of staying abroad, young age, and traveling under basic conditions. Of all travelers, 80% did not follow the traditionally recommended dietary restrictions. Among travelers visiting malaria-endemic areas, 20% did not carry any antimalarial drugs with them, not continuous chemoprophylaxis or standby medication., Conclusions: Because of the rising travel activity, especially to tropical countries, the importance of qualified pretravel advice consultation is increasing. To improve the travelers' health, attention needs to be paid to individual risk factors, the prevention and therapy of travelers' diarrhea, malaria prophylaxis, management of respiratory illness, and personal safety.

Background: Giardia Iamblia causes infection of the small intestine, which leads to malabsorption and chronic diarrhoea. Aim: To characterise the inherent pathomechanisms of G Iamblia infection. Methods: Duodenal biopsy specimens from 13 patients with chronic giardiasis and from controls were obtained endoscopically. Short-circuit current (Isc) and mannitol fluxes were measured in miniaturised Ussing chambers. Epithelial and subepithelial resistances were determined by impedance spectroscopy. Mucosal morphometry was performed and tight junction proteins were characterised by immunoblotting. Apoptotic ratio was determined by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labelling staining. Results: In giardiasis, mucosal surface area per unit serosa area was decreased to 75% (3%) of control, as a result of which epithelial resistance should increase. Instead, epithelial resistance of giardiasis biopsy specimens was decreased (19 (2) vs 25 (2) Ω cm2 p<0.05) whereas mannitol flux was not significantly altered (140 (27) vs 105 (16) nmol/h/cm2). As structural correlate, reduced claudin 1 expression and increased epithelial apoptosis were detected. Furthermore, basal lsc increased from 191 (20) in control to 261 (12) μA/h/cm2 in giardiasis. The bumetanide-sensitive portion of lsc in giardiasis was also increased (51 (5) vs 20 (9) μA/h/cm2 in control; p<0.05). Finally, phlorizin-sensitive Na+-glucose symport was reduced in patients with giardiasis (121(9) vs 83 (14) μA/h/cm2). Conclusions: G Iamblia infection causes epithelial barrier dysfunction owing to down regulation of the tight junction protein claudin 1 and increased epithelial apoptoses. Na+-dependent D-glucose absorption is impaired and active electrogenic anion secretion is activated. Thus, the mechanisms of diarrhoea in human chronic giardiasis comprise leak flux, malabsorptive and secretory components. [ABSTRACT FROM AUTHOR]