Emerging concepts in the diagnosis, treatment, and prevention of travelers’ diarrhea:

Injuries and medical emergencies among international travellers

BACKGROUND

Tropical infectious diseases and vaccine-preventable emergencies are the mainstay of pre-travel consultations. However, non-communicable diseases, injuries and accidents that occur during travel are not emphasized enough in these settings.

METHODS

We performed a narrative review based on a literature search of PubMed, Google Scholar, UpToDate, DynaMed and LiSSa and on reference textbooks and medical journals dedicated to travel, emergency and wilderness medicine. Relevant secondary references were extracted. We also aimed to discuss newer or neglected issues, such as medical tourism, Coronavirus Disease 2019, exacerbations of co-morbidities associated with international travel, insurance coverage, health care seeking abroad, medical evacuation or repatriation and tips for different types of travellers' emergency medical kits (personal, group, physician handled).

RESULTS

All sources reviewed led to the selection of >170 references. Among epidemiological data on morbidity and deaths while abroad, only retrospective data are available. Deaths are estimated to occur in 1 in 100 000 travellers, with 40% caused by trauma and 60% by diseases, and <3% linked to infectious diseases. Trauma and other injuries acquired during travel, such as traffic accidents and drowning, can be reduced by up to 85% with simple preventive recommendations such as avoiding simultaneous alcohol intake. In-flight emergencies occur on 1 in 604 flights on average. Thrombosis risk is two to three times greater for travellers than for non-travellers. Fever during or after travel can occur in 2-4% of travellers, but in up to 25-30% in tertiary centres. Traveller's diarrhoea, although rarely severe, is the most common disease associated with travel. Autochthonous emergencies (acute appendicitis, ectopic pregnancy, dental abscess) can also occur.

CONCLUSIONS

Pre-travel medicine encounters must include the topic of injuries and medical emergencies, such as the risk-taking behaviours and foster better planning in a comprehensive approach along with vaccines and infectious diseases advices.

Multistate nontyphoidal Salmonella and Shiga toxin-producing Escherichia coli outbreaks linked to international travel-United States, 2017-2020

Enteric bacterial infections are common among people who travel internationally. During 2017-2020, the Centers for Disease Control and Prevention investigated 41 multistate outbreaks of nontyphoidal Salmonella and Shiga toxin-producing Escherichia coli linked to international travel. Resistance to one or more antimicrobial agents was detected in at least 10% of isolates in 16 of 30 (53%) nontyphoidal Salmonella outbreaks and 8 of 11 (73%) Shiga toxin-producing E. coli outbreaks evaluated by the National Antimicrobial Resistance Monitoring System. At least 10% of the isolates in 14 nontyphoidal Salmonella outbreaks conferred resistance to one or more of the clinically significant antimicrobials used in human medicine. This report describes the epidemiology and antimicrobial resistance patterns of these travel-associated multistate outbreaks. Investigating illnesses among returned travellers and collaboration with international partners could result in the implementation of public health interventions to improve hygiene practices and food safety standards and to prevent illness and spread of multidrug-resistant organisms domestically and internationally.

Public Health Importance of Emporiatrics: A Review

People travel all around the world to explore, trade, sojourn, etc. Millions of individuals cross national and international borders. Travel medicine services are offered by general practitioners, specialized travel clinics, or immunization centers. Epidemiology, illness prevention, and travel-related self-treatment are all included in the interdisciplinary field of travel medicine. The main objective is to keep travelers alive and in good health, by reducing the effects of illness and accidents through preventative measures and self-care. The danger to a traveler's health and well-being must be understood, and the travel medicine practitioner's job is to help their patient or client recognize and manage those risks. The absence of any disease or symptom does not always indicate good health. Chronic illness sufferers, including those with cancer, diabetes, and hypertension, can maintain a reasonable level of health and mobility. Travel medicine is a rapidly developing, extremely dynamic, multidisciplinary field that calls for knowledge of a range of travel-related illnesses as well as current information on the global epidemiology of infectious and non-infectious health risks, immunization laws and requirements around the world, and the shifting trends in drug-resistant infections. Pre-travel consultation aims to reduce the traveler's risk of disease and harm while on the road through preventive counseling, education, recommended drugs, and essential vaccines. Specialized medical guidance can help reduce the potential health risks of travel. Emporiatrics is not only used for traveling advice or things to be done during the period of the journey but it also creates room in implementing the interdisciplinary subject with new methods or development of new policies, technologies, and various programs to reduce unnecessary problems of the travelers, which will boost tourism.

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

Even though Italian Occupational Physicians (OP) are increasingly involved in the managing of overseas workers, their knowledge, attitudes, and practices (KAP) in travel medicine are mostly undefined. We, therefore, permed a KAP study specifically targeting the management of travelers' diarrhea (TD) by OP. A total of 371 professionals (43.4% males; mean age 40.8 ± 10.9 years) completed in 2 rounds (2019 and 2022) a specifically designed web questionnaire that inquired participating OP on their knowledge status (KS), risk perception, and management of TD through pre- and post-travel advice and interventions. Multivariable odds ratios (aOR) for predictors of a better knowledge status were calculated through regression analysis. Eventually, the majority of participants (53.4%) had participated in the management of cases of TD in the previous months, but only 26.4% were reportedly involved in pre-travel consultations. The overall knowledge status was unsatisfying (potential range: 0-100%, actual average of the sample 59.6% ± 14.6), with substantial uncertainties in the management of antimicrobial treatment. Interestingly, only a small subset of participants had previously prescribed antimicrobial prophylaxis or treatment (3.5% and 1.9%, respectively). Main effectors of a better knowledge status were: having a background qualification in Hygiene and Public Health (aOR 14.769, 95%CI 5.582 to 39.073), having previously managed any case of (aOR 3.107, 95%CI 1.484 to 6.506), and having higher concern on TD, reported by acknowledging high frequency (aOR 8.579, 95%CI 3.383 to 21.756) and severity (aOR 3.386; 95%CI 1.741 to 6.585) of this disorder. As the adherence of participating OP to official recommendations for TD management was unsatisfying, continuous Education on Travel Medicine should be improved by sharing up-to-date official recommendations on appropriate treatment options for TD.

Travellers' diarrhoea - prevention, trends and role of microbiome

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.

Multidrug-Resistant Lineage of Enterotoxigenic Escherichia coli ST182 With Serotype O169:H41 in Airline Waste

Enterotoxigenic Escherichia coli (ETEC) is the primary aetiologic agent of traveller’s diarrhoea and a significant cause of diarrhoeal disease and death in developing countries. ETEC O169:H41 strains are known to cause both traveller’s diarrhoea and foodborne outbreaks in developed countries and are cause for concern. Here, whole-genome sequencing (WGS) was used to assemble 46 O169:H41 (ST182) E. coli draft genomes derived from two airplane waste samples sourced from a German international airport. The ST182 genomes were compared with all 84 publicly available, geographically diverse ST182 genomes to construct a core genome-based phylogenetic tree. ST182 isolates were all phylogroup E, the majority serotype O169:H41 (n = 121, 93%) and formed five major clades. The airplane waste isolates differed by an average of 15 core SNPs (range 0–45) but their accessory genome content was diverse. While uncommon in other ST182 genomes, all airplane-derived ST182 isolates carried: (i) extended-spectrum β-lactamase gene bla_CTX–M–15 notably lacking the typical adjacent ISEcp1; (ii) qnrS1 and the S83L mutation in gyrA, both conferring resistance to fluoroquinolones; and (iii) a class 1 integron structure (IS26-intI1_Δ648-dfrA17-aadA5-qacEΔ1-sul1-ORF-srpC-padR-IS6100-mphR-mrx-mphA-IS26) identified previously in major extraintestinal pathogenic E. coli STs but not in ETEC. ST182 isolates carried ETEC-specific virulence factors STp + CS6. Adhesin/invasin tia was identified in 89% of aircraft ST182 isolates (vs 23%) and was located on a putative genomic island within a hotspot region for various insertions including PAI I₅₃₆ and plasmid-associated transposons. The most common plasmid replicons in this collection were IncFII (100%; F2:A-:B-) and IncB/O/K/Z (89%). Our data suggest that potentially through travel, E. coli ST182 are evolving a multidrug-resistant profile through the acquisition of class 1 integrons and different plasmids.

A comparison of two multiplex-PCR assays for the diagnosis of traveller's diarrhoea

Background

Numerous multiplex-PCR assays are now available in routine diagnostics but their clinical value is controversial if a clear association between clinical symptoms and the detection of a particular pathogen is missing. The objective of this work was to evaluate a multiplex-PCR assay for the diagnosis of traveller’s diarrhoea (TD) in a case-control study and to assess the concordance with the BioFire® FilmArray® Gastrointestinal Panel.

Methods

Stool samples from cases (n = 61) and controls (n = 30) were collected during travel and analysed by the GI-EB Screening assay (Seegene) in a case-control study. The concordance with the BioFire® FilmArray® Gastrointestinal Panel was expressed as the proportion of participants in which both tests agreed in the category “detected” and “not detected”.

Results

None of the test-target organisms (Campylobacter spp., Clostridioides difficile toxin A/B, Salmonella spp., Shigella spp./enteroinvasive Escherichia coli, E. coli O157, Shiga toxin-producing E. coli, Yersinia enterocolitica) was significantly associated with TD GI-EB Screening assay. The GI-EB Screening assay had an agreement with the BioFire® FilmArray® of 86.8–100%.

Conclusion

The selection of test-target organisms included in the GI-EB Screening assay appears inappropriate for the diagnostic work-up of TD as none of the detected pathogens was associated with TD. The GI-EB Screening assay had a good concordance with BioFire® FilmArray®.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-05885-3.