Part 1 of Essay
(TB) is an infectious disease caused by a germ (bacterium) called Mycobacterium . This germ primarily affects the lungs and may infect anyone at any age. In the United States, the number of TB cases steadily decreased until 1986 when an increase was noted; TB has continued to rise since. Today, ten million individuals are ....

Part 2 of Essay
.... In this case, the person would be infected, but not have active disease. Only about 10% of those infected will actually develop TB in their lifetimes. Active disease can occur in an infected person when the body's resistance is low or if there is a large or prolonged exposure to the germs that overcome the body's natural defenses. The body's response to active TB infection produces inflammation which can eventually damage the lungs. The amount of damage may be quite extensive, yet the symptoms may be minima ....