Cold Viruses Are in Aerosol or Droplets
The highest concentration of these cold viruses in nasal secretions occurs during the first three days of symptomatic infection. This is the period for the infected persons to be most contagious. Cold viruses may at times be present in the droplets that are expelled in coughs and sneezes.
Hands Contaminated with Cold Viruses
Nasal secretions containing cold viruses contaminate the hands of people with colds as a result of nose blowing, covering sneezes, and touching the nose. Also, cold viruses may contaminate objects and surfaces in the environment of a cold sufferer. Young children are the major reservoir of cold viruses and a particularly good source of virus containing nasal secretions.
Experiments have demonstrated that a cold virus readily transfers from the skin and hands of a cold sufferer to the hands and fingers of another person during periods of brief contact. Also, cold viruses readily transfer to the hands as a result of touching contaminated objects and surfaces.
Fingers Contaminated with Cold Viruses
Contaminated finger touches nasal mucosa and conjunctiva of eye. Viruses on the fingers are transferred into the nose and eye by finger-to-nose and finger-to-eye contact. Virus deposited in the eye promptly goes down the tear duct into the nose. Once in the nose, a cold virus is transported by mucociliary action to the adenoid area where it starts a cold.
In some instances, cold virus, which is expelled into the air in coughs and sneezes, may land in the nose or eye and cause infection.