The viral infectious cycle. Getting to a receptive cell . To initiate infection viruses must first get to a receptive cell. Probably herpesvirus and papilloma viruses cannot initiate infection on intact skin and need a break in the epithelium. Mucous membranes are easier to access for these viruses but are bathed in liquids that provide some protection either through the viscosity of the fluid or the presence of secreted IgA. Enteroviruses resist the acid pH of the stomach and reach the GI tract a major site of replication.
Enteroviruses can also replicate in the nasopharyngeal mucosa.
One form of enteroviruses, the Rhinoviruses, cause ony the common cold. They replicate in the nasophyngeal mucosa but are destroyed by an acid pH and so cannot replicate in the GI tract. Transmitting virus from one host to the next. Hands are the most important mechanism for transmitting viruses. Hands become contaminated with respiratory secretions, oral fluids, and feces.