Respiratory Viruses

Respiratory viruses are the most frequent causative agents of disease in humans, with significant impact on morbidity and mortality worldwide. Common respiratory agents from several virus families are well adapted to efficient person-to-person transmission and circulate in a global scale, and community-based studies conducted over the past five decades or so confirm that these viruses are the predominant etiological agents of acute respiratory infections (ARIs). The respiratory viruses that most commonly circulate in all continents as endemic or epidemic agents are influenza virus, respiratory syncytial virus, parainfluenza viruses, metapneumovirus, rhinovirus, coronaviruses, adenoviruses, and bocaviruses. Although vaccines and effective antiviral drugs are not yet available for most of these viruses, much progress has been made in the understanding of their biology and fundamental issues of host–parasite relationship. This article is a summary of the current knowledge about these viruses.