Diseases caused by Bacteria and Viruses

19-3

Bacteria cause disease• Bacteria produce disease in one of two

general ways. Some bacteria damage the cells and tissue of the infected organism directly by breaking down the cells for food. Other bacteria release toxins that travel throughout the body interfering with the normal activity of the host.

Control of bacterial growth• There are various methods used to control

bacterial growth, including sterilization, disinfectants and food processing.

Viruses cause Disease• Like bacteria, viruses produce disease by

disrupting the body’s normal equilibrium.

• In many viral infections, viruses attack and destroy certain cells in the body, causing the symptoms of the disease.