Viral infections commonly affect the upper or lower respiratory tract. There are many different types of viruses that can affect the breathing passages and cause respiratory illnesses such as a cold or flu-like illness. Some of the common respiratory viruses include influenza virus, respiratory syncytial virus, parainfluenza virus, adenovirus, rhinovirus, human metapneumovirus and enterovirus. Influenza virus infection and respiratory syncytial virus infection are not included here as they are covered elsewhere. Treatment of viral respiratory infections is usually supportive.
. Sometimes antiviral drugs