Astrovirus Pathogenesis

Abstract

Astroviruses are a major cause of diarrhea in the young, elderly, and the immunocompromised. Since the discovery of human astrovirus type 1 (HAstV-1) in 1975, the family Astroviridae has expanded to include two more human clades and numerous mammalian and avian-specific genotypes. Despite this, there is still little known about pathogenesis. The following review highlights the current knowledge of astrovirus pathogenesis, and outlines the critical steps needed to further astrovirus research, including the development of animal models of cell culture systems.

Astrovirus infections induce age-dependent dysbiosis in gut microbiomes of bats

“…The AstV*age interaction was significant in the models. In Jamaican fruit bats as well as in other studies on bats [31] and humans [3] the AstV prevalence was found to be higher in young individuals. More research including experimental AstV-infection of individuals with healthy and dysbiotic microbiomes can help to proof such cause-and-effect relationships.…”

“…Astroviruses are a major cause of diarrhoea in children [1]. Interestingly, -and in contrast to strong health effects they have in humans-some wildlife species, including bats, remain phenotypically asymptomatic after infection [3]. However, disease symptoms after AstV-infection may only be less visible in bats.…”

“…In adult bats, the increase in bacterial diversity might be the result of a better immune-mediated counter-response against AstV-infection, either simply because of the more effective immune system in adulthood or because of an acquired immunity against repeated AstVinfections [36]. This might be the reason that AstV-infections in children cause more pathological symptoms and higher disease severity than in adults [3]. If this is the case, one would expect that not all bacterial taxa are similarly affected by AstV-infection but react in a different manner depending on their function.…”

“…In humans, HAstV-infections lead to an increased intestinal epithelial cell permeability by disrupting cellular tight junctions and thereby causing the loss of ability of the intestine to reabsorb water and nutrients [2]. However, infections in healthy children, in adults and, especially, in some animal species remain asymptomatic, although little is known about the pathogenesis of the disease [3]. For example, murine-AstVinfected laboratory mice exhibit no diarrhoea, despite an increase in intestinal permeability.…”

“…Contrariwise, because of the direct contact of the gut microbiome and its protective role, it is also probably a target of enteric viruses such as AstV. Thus, an investigation into changes in the diversity and bacterial abundance pattern of the gut microbiome might be a missing link in understanding the effects of an AstV-infection and also its potential as a driver of co-infections, an area of research that has been largely neglected so far [3].…”