ABSTRACT
Viruses are a well-known cause of infection of the respiratory tract (RT). This chapter provides an overview of the various aspects of viral infections of the human RT. The human RT is in direct contact with the external environment. Transmission of respiratory viruses can occur through aerosols, or respiratory droplets, or via indirect contact with infected secretions, or contaminated environmental surfaces. The chapter describes the major viral acute respiratory tract infection resulting in upper respiratory tract infection and lower respiratory tract infection, their clinical manifestations, and the currently available intervention strategies. Fever is unusual in patients with acute bronchitis, which may be caused by a variety of respiratory viruses including influenza virus, parainfluenza virus, coronavirus, rhinovirus, respiratory syncytial virus, and human metapneumovirus. Acute respiratory distress syndrome is a consequence of alveolar injury and can be caused by a variety of insults, including sepsis, aspiration, trauma, and pneumonia.
