Human and animal diseases are often caused by viruses or bacteria. Over the past two hundred or so years, vaccines have eradicated some of these diseases. Others have returned to haunt humans with new and ever-mutating strains, or revived when vaccination programs were interrupted. Communicable diseases may spread in different ways: through blood, air, feces/urine, food, or water. The World Health Organization (WHO) and the Center for Disease Control (CDC) keep constant watch over the most potentially dangerous diseases and the most likely threats to various world populations.
New diseases (such as MRSA) and the possibility of a pandemic avian flu have also raised international concerns about health. As populations grow (see the Demographics lab), especially when packed densely as in urban areas, there is increased risk of disease transmission. This lab will let you explore various diseases: Kold, a caricature of the common cold; Impfluenza, which resembles influenza; Neasles, with the high transmission rate of measles; and Red Death, a fast-spreading epidemic with a high mortality rate.
What factors come into play in the spread of these diseases? And what can we do to counter them?