sentence: People sitting close together appear at greater risk of becoming infected.
sentences_before: The common cold virus is usually spread in one of two main ways. The most common method of transmitting the cold virus has not been determined. The viruses may survive for a long time in the environment. Viruses may than be transmitted from the hands to the eyes or nose where infection occurs.
sentences_after: Transmission is common in daycare and at school, due to the closeness of many children with little immunity and frequently poor hygiene. These infections are then brought home to other members of the family. There is no evidence that the air on commercial flights transmits cold viruses. Rhinoviruses are most infectious in the first three days of cold symptoms. They are much less infectious afterwards.
concept_name: People
headings: Common cold Cause Transmission
categories: Diseases caused by viruses