1. 40.1 Infectious Disease

2. Disease Any change, other than an injury, that disrupts the normal functions of the body.

3. Pathogen Disease-causing agent.

4. Germ Theory of Disease Idea that infectious diseases are caused by microorganisms, or germs.

5. Koch’s Postulates Series of guidelines used to identify the microorganism that causes a specific disease.

6. Vector Animal that carries pathogens from person to person.

7. Antibiotic Compound that blocks the growth and reproduction of bacteria.

8. Key Concept Some diseases are produced by agents, such as bacteria, viruses, and fungi. Others are caused by materials in the environment, such as cigarette smoke. Still others, such as hemophilia, are inherited.

9. Key Concept Some infectious diseases are spread from one person to another through coughing, sneezing, or physical contact. Other infectious diseases are spread through contaminated water or food. Still others are spread by infected animals.