Clinical Definition

Viruses may gain access to the body through various routes, including the digestive, reproductive and respiratory system. Viruses that are pathogenic to humans begin to use the host’s cells to reproduce and cause disease. Viral receptors attach and penetrate healthy cells and use those cells in order to replicate. The severity of a viral infection varies greatly and depends both on the virus and the body’s response.

In Our Own Words

There are a few hundred viruses identified that cause illness in humans. A virus gains entrance into the body through any opening, such as the nose or mouth. Some viruses can also enter the body through the reproductive system. Once inside, they can invade and hijack healthy cells to make their own biologic molecules and to reproduce. Viruses vary greatly in which cells and tissues they are able to infect. Viral infections differ from bacterial infections and are not treated with antibiotics, but some cases, antiviral medication is used.