CaliciviridaeandAstroviridae

Abstract

Caliciviruses and astroviruses, along with rotavirus, are regarded as important causes of viral gastroenteritis. Surveillance studies using recently developed molecular diagnostic methods have also highlighted the importance of human astroviruses and other underreported pathogens as important causes of pediatric acute gastroenteritis. Epidemiological information on human caliciviruses and astroviruses is providing data required to assess the economic burden of the disease and justify the development of prevention strategies, including vaccination. A section describes what is now known about the activation of innate responses after both human and nonhuman calicivirus infections, and specifically emphasizes the effect that innate antiviral responses might have on restricting human norovirus propagation in vitro. To date, the role of innate immunity in controlling infections caused by caliciviruses has been demonstrated for murine norovirus (MNV) and porcine enteric calicivirus (PEC), but only limited data are available to confirm this for human noroviruses. As positive-sense RNA viruses, there are several steps in the replication cycle of caliciviruses and astroviruses where the cellular antiviral machinery could detect foreign viral components. Exploration of the interplay between caliciviruses and astroviruses and the interferon (IFN) response not only will help us to better understand viral pathogenesis but also can result in novel vaccination strategies and therapies. This chapter concludes with a few remarks meant to stimulate discussion and future studies to better understand the interplay between calicivirus and astrovirus infections and the cellular antiviral responses.