Patents are designed to protect creations and designs, but how long a patent lasts for is dependent on a number of factors. The length of time that a patent offers protection, depends largely on what type of patent is issued and whether required maintenance fees are paid to keep the patent active. slide 1 of 6.
A viral infection is a disease that can be caused by different kinds of viruses, of which the influenza-virus is best known.
Types of Viral Infections. Viruses can affect any part of the body or body system, and can cause infections such as the common cold, flu, gastroenteritis, chicken pox or herpes. The most common type of viral infections involves the respiratory tract.he diagnosis of a viral infection is usually based on the physical symptoms and the history of the illness. A condition such as influenza, which is caused by a virus, is generally easy to diagnose because most people are familiar with the symptoms.