Unit 4: Diseases and Infection.(Brief Article)

Background Bonus

Before doctors realized that bacteria cause diseases, they did not scrub before treating a patient. They didn't even wash their hands before performing surgery. Many patients died not from illness or surgery but from a kind of infection in the bloodstream called sepsis, caused by unsterile instruments or unclean hands.

During the Civil War, more than half the soldiers who died were killed not by guns and swords but by infection and disease. In the late 1860s, Joseph Lister began disinfecting his operating room with carbolic acid, and the death rate dropped from 45 percent to 15 percent. Now sterilizing instruments, scrubbing hands, and wearing gloves is mandatory in operating rooms.

These improvements in sanitation, along with the discovery of antibiotics, have greatly improved the survival rate of children. About 100 years ago in the United States, at least 25 percent of children died from bacterial infections before they reached puberty. Now fewer than 5 percent die from bacterial infections before reaching puberty.

Unit Objectives

Students learn to

* identify bacteria and viruses as agents of communicable diseases;