Global Impact of Diarrheal Diseases That Are Sampled by Travelers: The Rest of the Hippopotamus

Abstract

Travelers who experience diarrhea (i.e., "turista") are exposed to the same pathogens and illnesses that pose some of the greatest threats to life and development among malnourished children in developing areas around the world, where inadequate water and poor sanitation remain. This article focuses on new findings about the impact, diagnosis, and control of these illnesses and the genetic predispositions of persons who acquire them. Despite the reductions in mortality due to dehydrating diarrhea, the morbidity associated with diarrheal illnesses continues unabated. Furthermore, we increasingly recognize the lasting detrimental effects of enteric infections that occur during early childhood on later physical and cognitive development and, in patients with acquired immunodeficiency syndrome, on the absorption of antiretroviral drugs. Genetic predispositions to inflammation and potential protection associated with such alleles as ApoE4, which are not suspected of being involved in diarrhea, remind us of how much we have to learn about the effect and interactions of enteric tropical infectious diseases with regard to our host genome. New diagnostic methods hold promise for improved recognition and, hopefully, control of enteric infections worldwide.

Diarrheagenic Escherichia coli in sub-Saharan Africa: Status, Uncertainties and Necessities

“…This too has provided much useful data in that etiologic agents of travellers' and infantile diarrhea are often similar; however, they are occasionally not and until any region is well-studied, the degree of overlap remains a subject of conjecture [3]. Also, many travellers do not share risk factors with endemic residents [96].…”

“…In recent years, childhood deaths from diarrhea have begun to fall worldwide, largely due to the introduction and widespread implementation of oral rehydration therapy. But in spite of heightened appreciation for risk factors such as unclean water, premature weaning, bottle-feeding, and malnutrition, the number of bouts of infantile diarrhea has risen steadily in the last decade and the decline in diarrheal disease deaths is least perceptible in the African continent [2][3][4].…”

“…(This is probably an overestimate of the true traveller's diarrhea attack rate since Peace Corpers, in their early 20s, have typically had little previous travel experience and are more likely to engage in risky or adventurous behavior) [10]. In many cases, etiologic agents of travellers' and infantile diarrhea are similar but in some cases they are not and the extent to which the etiology of these two syndromes overlap is not precisely known [3,11,12].…”

Role of apolipoprotein E4 in protecting children against early childhood diarrhea outcomes and implications for later development

“…Recent findings suggest that early cognitive development under the stresses of environmental toxins, early childhood diarrhea and malnutrition is modulated by apolipoprotein E (APOE) genotype, although not in healthy children in resource-rich countries [13], nor in favela children with low diarrhea burdens [14]. The single structural locus of APOE has three alleles on chromosome 19: APOE2, APOE3, the most frequent allele in populations studied to date [15], and APOE4.…”

A Comparative Study of Bacterial and Parasitic Intestinal Infections in India

“…Children and young adults are the most commonly affected group [1]. Worldwide, 17% under-five mortality has been attributed to diarrhea [2].…”