Adenovirus is a virus, so there is no cause, but the virus causes conditions such as the common cold, a sore throat, pneumonia, pinkeye and bronchitis, according to the Centers for Disease Control and Prevention. Adenoviruses usually do not cause serious illnesses or death, but those with a weak immune system may develop a serious illness due to the virus.
The transmission of adenoviruses is usually from one person to another, explains the Centers for Disease Control and Prevention. This occurs due to close personal contact, touching a surface with adenoviruses present or breathing the virus in through the air. It is also possible to contact adenoviruses through the stool or water, such as when swimming. It's possible that the virus may shed for several months following the infection, and this may occur without symptoms. However, the person may still be contagious during this time, even without symptoms.
There are no treatments for adenovirus, and most doctors only treat the symptoms of the virus, states the Centers for Disease Control and Prevention. There is no public vaccine for adenovirus, but a person can avoid the virus by taking steps such as washing his hands several times a day with soap and water and covering the nose and mouth when sneezing or coughing. Those who have the virus should also stay home when sick.