Communicable, or infectious, diseases are human illnesses caused
by viruses, bacteria, parasites, fungi and other microbes. These
diseases may be spread by direct contact with an infected person or
animal, by ingesting contaminated food or water, by insects like
mosquitoes or ticks (vectors), or by contact with contaminated
surroundings like animal droppings or even contaminated air.
With the introduction of antibiotics over 50 years ago, scientists made sweeping predictions heralding the end of death and suffering from infectious diseases. However, during the past 25 years, microbes have demonstrated their tremendous ability to adapt, survive and challenge us. Infectious diseases remain the leading cause of death worldwide.
Of the top ten causes of death compiled by the World Health Organization for 2004, five were due to infectious diseases. In the United States, two of the ten leading causes of death are infectious diseases (HIV/AIDS and pneumonia/ influenza). The Centers for Disease Control and Prevention (CDC) reports that 160,000 Americans die each year with an infectious disease as the underlying cause of death.
This course will introduce you to a variety of communicable diseases, routes of disease transmission, and disease control terminology.