Traveler’s Diarrhea

Travelers’ foodborne disease or diarrhea (TD) is a global problem and is more likely to, but not exclusively, occur when tourists from a higher income country return from a lower income country. Often viewed as a mild illness, the consequences can be serious both for the tourist as well as any business implicated in its causation. The vast majority of TD is thought to be spread via contaminated foods. Responsibility for the prevention of TD lies partly with governments and travelers themselves but primarily with the businesses who are supplying them with food. Particular care needs to be taken with the supply and production of artisan and street vended foods. Sporting events can pose a logistical food safety challenge in the supply of large volumes of safe food to participants and visitors within a short timescale. Food safety management advice for the prevention of TD is provided. One consequence of causing TD is that travelers may seek compensation through the courts. These cases will particularly involve large hotels/resorts and all-inclusive holidays. In order to assist in a defense against accusations of causing TD, defendants need to be able to demonstrate that they had, and were operating, an effective food safety management system. Advice on how this can be achieved is provided.

El aumento de los viajes a zonas tropicales y subtropicales ha causado un incremento de las patologías importadas en los países occidentales. La diarrea del viajero es una de las principales patologías importadas. Supone la principal causa de consulta médica tras un viaje internacional, aunque normalmente es leve y autolimitada. Tiene un alto impacto en el normal transcurso del viaje. Debido a que la ingesta de alimentos o bebidas contaminadas es el origen de la mayoría de los casos, la prevención es el pilar fundamental. Asimismo y debido a su alta incidencia, se ha de aconsejar a los viajeros sobre la posibilidad de realizar autotratamiento.

The increase in travel to tropical and subtropical areas has caused an increase in imported disease in Western countries. Traveler's diarrhea is one of the main imported diseases. Though normally mild and self-limited, it is the principal cause for a medical consultation after an international trip. It has a big impact on the normal course of the trip. Give that the intake of contaminated food and drinks is the origin of most cases, prevention is the fundamental pillar. Likewise, due to its high incidence, travelers should be advised about the possibility of self-treatment.

Travellers’ diarrhoea (TD) is the most frequent illness experienced by international travellers to lower-income countries with bacterial agents considered to account for 80–90% of cases. In this review, we summarise evidence published on bacterial TD over the past 10 years, focusing on the epidemiology and aetiology of TD. Diarrhoeagenic Escherichia coli (DEC) continue to be the most commonly implicated bacteria in TD, although Enteropathogenic E. coli (EPEC) and Enteroaggregative E. coli (EAEC) now appear to be predominant where Enterotoxigenic E. coli (ETEC) was previously considered most prevalent globally. Where fluroquinolone resistance had primarily been documented for Campylobacter in Southeast Asia, widespread resistance has been observed in most regions of the world for multiple enteropathogens, including Shigella, Salmonella, ETEC and EAEC. Implementation of novel molecular methods for pathogen detection has led to identification of bacterial pathogens, including Clostridium difficile (with and without the use of prior antibiotics), Arcobacter species and Bacteroides fragilis, as aetiological agents in TD. The widespread resistance to first-line antibiotics in multiple bacterial enteropathogens warrants continued surveillance and re-evaluation of current treatment practices. Further investigations are required to determine the prevalence and geographical distribution of bacterial enteropathogens that have been more recently implicated in TD.

This study aimed at evaluating the antimicrobial potential of aqueous, ethanolic and methanolic extracts of two Cameroonian plants against selected foodborne pathogens. Bioactive compounds were extracted from Millettia laurentii De Wild seeds and Lophira alata Banks ex. C. F. Gaertn leaves using distilled water, ethanol and methanol as solvents. The extracts were tested against Escherichia coli O157, Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa, Proteus mirabilis, Moraxella morganii, Salmonella enteritidis, Klebsiella pneumoniae and Listeria monocytogenes using the microdilution method. The results showed that distilled water extracted a more important mass of phytochemical compounds (18.0–24.60%) compared to ethanol (4.80–5.0%) and methanol (4.20–4.60%). All the extracts exhibited significant antimicrobial activity with MIC values ranging from 5 to 20 μg/mL for M. laurentii seeds extracts and from 1.0 to 20 μg/mL for L. alata leaves extracts. The different plant extracts were ten times less active than gentamicin. The most active extracts were obtained using ethanol as solvent and K. pneumoniae was the most resistant pathogen to all extracts (MBC>20 μg/mL). M. laurentii extracts were bactericidal against L. monocytogenes and P. mirabilis while the reference antibiotic (gentamicin) was bacteriostatic against these pathogens. The results obtained from this study suggest the studied local plant materials as a source of antimicrobial compounds which can be valorized in the medical field as substitute of antibiotics for which many microorganisms have nowadays developed resistance mechanisms. Further studies need to be performed in order to characterize and identify these antimicrobial active molecules.

Different health risks are associated with international electives among medical students, including the transmission of infectious diseases and non-communicable diseases. This review aims to summarise the evidence for illnesses associated with travel in medical students taking part in electives abroad.

Articles were identified through a literature search in two databases (until 30 July 2020) - PubMed and Web of Science.

Sixteen articles were included in the systematic review. The results were classified into two broad categories: communicable diseases and non-communicable diseases. Gastrointestinal infections including travellers’ diarrhoea were the most common infectious diseases reported by medical students abroad, followed by respiratory tract infections and skin infections. Blood-borne and sexually transmitted infection and systemic febrile infections due to vector-borne pathogens were rarely reported. Only six of the 16 studies addressed microbial carriage. The acquisition of resistant bacteria appeared to be frequent. Traffic accidents and mental health problems were also reported.

One of the lessons learned from this review is the requirement for large-scale epidemiological studies to evaluate the burden of infectious diseases such as gastrointestinal, respiratory and blood-borne infections with microbiological documentation. In particular, the emergence of the acquisition of resistant bacteria may lead to a theoretical risk of spread to the community and hospitals. Studies addressing mental health issues in the context of medical electives abroad are also needed.

International travel has increased dramatically over the past 50 years, and travel destinations have diversified. Although physicians are more familiar with the panel of aetiological agents responsible for illnesses of returning travellers, thanks to regular epidemiological studies, the spectrum of pathogens potentially encountered in various travel destinations is nevertheless increasing. In addition, the wide array of approaches currently available and addressed in this paper could render the procedures for microbiological analyses increasingly complex. As the time to result is crucial to adequately manage patients, modern approaches have been developed to shorten diagnosis delays. The syndromic approach, which consists of simultaneously testing a wide panel of microorganisms, substantially increases the diagnostic yield with significant time savings, particularly when coupled with point-of-care laboratories. The tools commonly used for this purpose are immunochromatographic tests, mainly targeting bacterial antigens, and multiplex real-time PCR. The emergence of next-generation sequencing technologies, which enable random amplification of genetic material of any microbe present in a clinical specimen, provides further exciting perspectives in the diagnosis of infectious diseases.