Travelers' Diarrhea in Children at Risk: An Observational Study From a Spanish Database

Bacterial travellers' diarrhoea: A narrative review of literature published over the past 10 years

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.

Evaluation and Management of Traveler's Diarrhea in Children

Traveler's diarrhea is the most common travel disease in both children and adults. Adult guidelines for traveler's diarrhea have been established, but significant gaps persist in guidance for the evaluation and management of pediatric traveler's diarrhea. Adult guidelines are not necessarily applicable in children, and it is essential for clinicians to account for the differences in pediatric pathophysiology, clinical presentations, and treatment recommendations when evaluating and managing pediatric traveler's diarrhea.

Intestinal giardiasis in children: Five years' experience in a reference unit

BACKGROUND

Giardiasis is highly prevalent in children and is often mildly symptomatic. First-line treatment is metronidazole, but treatment failure is not uncommon. We describe a paediatric series, to identify risk factors for treatment failure and to analyse the safety and effectiveness of other treatment strategies.

METHODS

Retrospective observational study, including children diagnosed with giardiasis from 2014 to 2019. Diagnosis was based on direct visualisation by microscopy after concentration using an alcohol-based fixative, antigen detection and/or DNA detection by polymerase chain reaction in stool. Treatment failure was considered when GI was detected 4 weeks after treatment.

RESULTS

A total of 120 patients were included, 71.6% internationally adopted, median age 4.2 (2.3-7.3) years. Only 50% presented with symptoms, mainly diarrhoea (35%) and abdominal pain (14.1%); co-parasitism was frequent (45%). First-line treatment failure after a standard dose of metronidazole was 20%, lowering to 8.3% when a higher dose was administered (p < 0.001). Quinacrine was administered in 10 patients, with 100% effectiveness. Children <2 years were at higher risk of treatment failure (OR 3.49; 95% CI 1.06-11.53; p = 0.040).

CONCLUSIONS

In children with giardiasis, treatment failure is frequent, especially before 2 years of age. Quinacrine can be considered as a second-line treatment. After treatment, eradication should be confirmed.

Natural Infection with Giardia Is Associated with Altered Community Structure of the Human and Canine Gut Microbiome

While enteric parasitic infections are among the most important infections in lower- and middle-income countries, their impact on gut microbiota is poorly understood. We reasoned that clinical symptoms associated with these infections may be influenced by alterations of the microbiome that occur during infection. To explore this notion, we took a two-pronged approach. First, we studied a cohort of dogs naturally infected with various enteric parasites and found a strong association between parasite infection and altered gut microbiota composition. Giardia, one of the most prevalent parasite infections globally, had a particularly large impact on the microbiome. Second, we took a database-driven strategy to integrate microbiome data with clinical data from large human field studies and found that Giardia infection is also associated with marked alteration of the gut microbiome of children, suggesting a possible explanation for why Giardia has been reported to be associated with protection from moderate to severe diarrhea.

Enteric parasitic infections are among the most prevalent infections in lower- and middle-income countries (LMICs) and have a profound impact on global public health. While the microbiome is increasingly recognized as a key determinant of gut health and human development, the impact of naturally acquired parasite infections on microbial community structure in the gut, and the extent to which parasite-induced changes in the microbiome may contribute to gastrointestinal symptoms, is poorly understood. Enteric parasites are routinely identified in companion animals in the United States, presenting a unique opportunity to leverage this animal model to investigate the impact of naturally acquired parasite infections on the microbiome. Clinical, parasitological, and microbiome profiling of a cohort of 258 dogs revealed a significant correlation between parasite infection and composition of the bacterial community in the gut. Relative to other enteric parasites, Giardia was associated with a more pronounced perturbation of the microbiome. To compare our findings to large-scale epidemiological studies of enteric diseases in humans, a database mining approach was employed to integrate clinical and microbiome data. Substantial and consistent alterations to microbiome structure were observed in Giardia-infected children. Importantly, infection was associated with a reduction in the relative abundance of potential pathobionts, including Gammaproteobacteria, and an increase in Prevotella—a profile often associated with gut health. Taken together, these data show that widespread Giardia infection in young animals and humans is associated with significant remodeling of the gut microbiome and provide a possible explanation for the high prevalence of asymptomatic Giardia infections observed across host species.

IMPORTANCE While enteric parasitic infections are among the most important infections in lower- and middle-income countries, their impact on gut microbiota is poorly understood. We reasoned that clinical symptoms associated with these infections may be influenced by alterations of the microbiome that occur during infection. To explore this notion, we took a two-pronged approach. First, we studied a cohort of dogs naturally infected with various enteric parasites and found a strong association between parasite infection and altered gut microbiota composition. Giardia, one of the most prevalent parasite infections globally, had a particularly large impact on the microbiome. Second, we took a database-driven strategy to integrate microbiome data with clinical data from large human field studies and found that Giardia infection is also associated with marked alteration of the gut microbiome of children, suggesting a possible explanation for why Giardia has been reported to be associated with protection from moderate to severe diarrhea.

Traveler's diarrhea in children: New insights and existing gaps

The number of children accompanying their parents in international travel is increasing steadily, and with the rising global migration, children more frequently accompany their parents or caregivers for visiting friends or relatives (VFR). As compared to travel for tourism, VFR children are at higher risk of acquiring local diseases, as they more often stay in rural areas in resource-poor locations, have longer periods of visit, are less likely to attend pre-travel consultations, and less frequently adhere to recommended precautions. Travelers's diarrhea (TD) is the most common travel-associated illnesses in children. This review updates the existing knowledge on TD in children, regarding its distinctive epidemiology, risk factors, preventive measures, clinical manifestations, complications, causative microorganisms and management. Despite the limited focused research on pediatric TD, which challenges the formulation of children-oriented evidence-based guidelines, practical recommendations are suggested.

A Comparison of Pretravel Health Care, Travel-Related Exposures, and Illnesses among Pediatric and Adult U.S. Military Beneficiaries

We evaluated differences in pretravel care, exposures, and illnesses among pediatric and adult travelers, using a prospective, observational cohort. Eighty-one pediatric travelers were matched 1:1 with adult military dependents by travel region, destination's malaria risk, and travel duration. Pediatric travelers were more likely to have coverage for hepatitis A and B (90% versus 67% of adults; 85% versus 44%), visit friends and relatives (36% versus 16%), report mosquito bites (69% versus 44%), and have close contact with wild or domesticated animals (40% versus 20%) than adults (P < 0.05). Subjects < 10 years of age were less likely to be prescribed antibiotics (28% versus 95%; RR = 0.63; 95% CI: 0.46-0.85) and antidiarrheals (9% versus 100%; RR = 0.10; 95% CI: 0.03-0.29) for travelers' diarrhea (TD) self-treatment than adults. Travel medicine providers should emphasize strategies for vector avoidance, prevention of animal bites and scratches, and TD self-treatment in pediatric pretravel consultations.

Giardia: a pathogen or commensal for children in high-prevalence settings?

PURPOSE OF REVIEW

Giardia is a common intestinal parasite worldwide, and infection can be associated with clear and sometimes persistent symptomatology. However, in children in high-prevalence settings, it is not associated with or is perhaps even protective against acute diarrhea, and the association with long-term outcomes has been difficult to discern.

RECENT FINDINGS

Recent studies have made progress in helping us disentangle this apparent paradox. First, prospective, well-characterized cohort studies have added to the data on the association between Giardia and diarrhea in these settings and have further characterized associations between Giardia infection and nutrition, gut function, and growth. Second, animal models have further characterized the host response to Giardia and helped elucidate mechanisms by which Giardia could impair child development. Finally, new work has shed light on the heterogeneity of human Giardia strains, which may both explain discrepant findings in the literature and help guide higher-resolution analyses of this pathogen in the future.

SUMMARY

The true clinical impact of endemic pediatric giardiasis remains unclear, but recent prospective studies have confirmed a high prevalence of persistent, subclinical Giardia infections and associated growth shortfalls. Integrating how nutritional, microbial, metabolic, and pathogen-strain variables influence these outcomes could sharpen delineations between pathogenic and potentially beneficial attributes of this enigmatic parasite.

6-year review of +Redivi: a prospective registry of imported infectious diseases in Spain

BACKGROUND

Understanding and detecting imported diseases is a priority in the prevention and management of prevalent and emergent infectious diseases acquired abroad. The +Redivi network measures the burden of imported infections in Spain and is essential for closing the gap in travel medicine.

METHODS

Demographic characteristics, travel information, syndromes and confirmed travel-related diagnoses were registered in a standardised online database.

RESULTS

A total of 10 767 cases of imported infectious diseases were registered between October 2009 and December 2015. Of these, 60.8% of cases were immigrants seen for the first time after arrival, 20.6% were travellers, and 18.4% were individuals visiting friends and relatives (VFR [immigrants and travellers]). The median time between arrival and medical consultation was 5.5 years for immigrants, 2.0 weeks for travellers, 3.1 weeks for VFR-travellers and 11.4 for VFR-immigrants. The most prevalent diagnoses were Chagas disease in immigrants and nonspecific acute diarrhoea in travellers. Malaria by P. falciparum was one of the most prevalent diagnoses among VFR. More than half the travellers saw a physician before travelling, although one-third of those for whom antimalarial medication was indicated did not take their medication correctly. As for VFR, only 10.4% of VFR-immigrants and 32.5% of VFR-travellers sought pre-travel advice. Only 23 and 21%, respectively, of those for whom antimalarial prophylaxis was indicated took the medication properly.

CONCLUSIONS

+Redivi provides a clear picture of the prevalence of imported infectious diseases among travellers and immigrants in Spain. The data collected could be used to improve everyday health care provided to travellers and immigrants after travel, to guide pre-travel consultations and to monitor the potential occurrence of tropical or exotic infectious diseases.

Epidemiology of travellers' diarrhea

BACKGROUND

Travellers' diarrhea (TD) continues to be the most frequent health problem in travellers with destinations in lower income parts of the world as compared with where they reside, even if that risk has slightly decreased.

METHODS

A systematic review was published 18 months ago; now PubMed was searched for more recent publications relating to travel, diarrhea, epidemiology, incidence, risk.

RESULTS

A trend to decreasing incidence rates have been noted in this as compared with the last century, but TD remains frequent. The clinical picture varies from a trivial ailment to severe with subsequent hospitalization. Of great concern are long-term sequelae, particularly post-infectious irritable bowel syndrome. The most important risk factors are the destination and duration of exposure among the environmental factors, whereas the age is the most relevant host factor.

CONCLUSIONS

Even if improved hygienic conditions in low-income countries often visited by travellers have resulted in slightly diminished incidence rates of TD, this remains a frequent health problem. Visitors to such destinations must be informed about that health risk and it is beneficial to equip them with instructions and a travel kit to enable them to some extent self-manage TD occurring abroad.