Final answer:
Close contact COVID-19 exposure typically involves inhaling airborne droplets from an infected person or contact with their saliva, skin, or eye secretions. It is facilitated by touching surfaces that have been contaminated by an infected person, which is common in urban environments with high population density.
Step-by-step explanation:
Close contact COVID-19 exposure is defined by interactions that increase the risk of transmitting the virus between individuals. The virus, which is highly contagious, spreads primarily through airborne transmission when someone inhales respiratory secretions such as droplets from coughing, sneezing, or exhaling by an infected person. Additionally, it can spread through direct contact with the saliva, skin rash, or eye secretions of an infected individual. In an urban setting, the concentration of large numbers of people greatly facilitates the spread by touch, including when infected individuals touch objects like tools and doorknobs subsequently touched by others. More than 200 viruses, including rhinoviruses, coronaviruses, and adenoviruses, can be transmitted in this manner, either by direct contact, aerosols, or environmental surfaces.