Travellers' diarrhoea - prevention, trends and role of microbiome

Abstract

Objectives: In this review, we present a contemporary look at the management of travellers' diarrhoea (TD), and we discuss the potential role of a microbiome as well as the administration of live microorganisms in order to prevent TD.Methods: We performed a comprehensive search using the PubMed and Web of Science databases for the period 2014-2021, looking for original and review articles on travellers' diarrhoea.Results: TD belongs among the most frequent illnesses experienced by travellers. For the most part, it is manifested as an acute yet self limiting condition, and only in a few cases proceeds to a prolonged form. Epidemiological analyses have shown that the majority of TD cases are caused by bacterial infections. In practice, pharmacological therapy is often used in the prevention and treatment of TD, since patients naturally seek preventive measures against the development of its severe course and its impact on planned activities. Bismuth salicylate is a strongly recommended TD prophylaxis but is not available on all European Union markets. Although the antibiotic prophylaxis is not generally recommended in guidelines, some antibiotic or chemotherapeutic agents are accessible over-the-counter in certain countries, and travellers are routinely encouraged to use them preventively. This routine can alter the microbiome of the traveller and promote the spread of drug resistant bacteria in their place of residence. Probiotic administration is considered safe, although the quality of evidence in favour of its prophylactic use in TD is currently low.Conclusions: The challenge for public health authorities is to educate personnel that can directly influence the behaviour of travellers through safe and effective pharmacological alternatives to antibiotics. Manipulation of the gut microbiome using specific probiotic strains can represent a safe and promising intervention.

The Intestinal Microbiome in Humans: Its Role for a Healthy Life and in the Onset of Diseases

“…Mild TD characterizes as 3 unformed stools without other symptoms and does not interfere with the ability of the travelers to continue their activity. In the case of moderate TD, patients suffer from 3 to 5 or more unformed stools a day, without other symptoms, compared to severe TD that consists of more than 5 stools in 24 hours associated with abdominal cramps, fever, vomiting, tenesmus, or blood in feces [129].…”

“…could also be responsible for TD. Recent papers have suggested that enteropathogenic E. coli and enteroaggregative E. coli are more common than enterotoxigenic E. coli-producing heat-labile or heat-stable toxin, which was previously thought to be the most frequent cause of TD [129].…”

Revisiting the Intestinal Microbiome and Its Role in Diarrhea and Constipation

“…Intestinal colonization with E. coli is followed by the production of diarrheagenic toxins, such as the Shiga-like toxin produced by EHEC or the heat-labile and the heat-stable enterotoxins produced by ETEC [69]. Enteropathogenic E. coli (EPEC) and EAEC are the most frequently involved pathogens in the development of traveler's diarrhea (TD), a condition with different grades of severity that is defined as three or more unformed stools in a day associated with abdominal pain, vomiting, or fever, which can affect a traveler's activity [71]. C. difficile is a Gram-positive anaerobic spore-forming bacillus present in the intestines of both humans and animals and an important nosocomial pathogen.…”

Management and Prevention of Traveler’s Diarrhea: A Cross-Sectional Study on Knowledge, Attitudes, and Practices in Italian Occupational Physicians (2019 and 2022)

“…TD has acquired a distinctive significance in occupational settings, as individuals afflicted by TD during their travels are also precluded from participation in daily workrelated activities [6,11,13,14]. Particularly where appropriate medical support may be quite difficult to obtain and rely on because of linguistic and/or infrastructural issues, or even remoteness, Occupational Physicians (OP) may represent key players in implementing an appropriate preventive and on-site management of TD in overseas workers [15][16][17].…”