| ?The endemic and epidemic diseases in Scotland fall chiefly, as is usual, on the poor.? So wrote the British economist and sociologist Thomas Robert Malthus in his 1798 treatise on population. In this work, Malthus gave dire warnings of the poverty and distress that would result if the world?s population continued to grow unchecked. Yet the only population controls he could conceive of were famine, war, and disease, especially endemic or epidemic diseases. Endemic, built from the prefix en-, ?in or within,? and Greek demos, ?people,? describes a disease that is restricted to a particular region, such as cholera and plague in parts of Asia. Epidemic, built from the prefix epi-, ?upon? and demos, is used to refer to a disease that involves many more people than usual in a particular community or a disease that spreads into regions in which it does not normally occur. Occurrences of influenza often result in epidemics. In fact, Hippocrates described such an epidemic that occurred in 412 B.C. But history has at least one example of an influenza epidemic that was so vicious it outgrew the classification of epidemic and became pandemic, or worldwide, in scope. The 1918 influenza pandemic killed 20 million people?548,000 in the U.S. alone?a toll that made it a tragic example of the effectiveness of one of Malthus?s methods for population control. | 1 |
| Widespread disease in populations of animals other than humans is referred to as being epizootic, a term constructed from epi-, Greek zoo, ?living being,? and the suffix -otic, ?specified condition or disease.? Epizootic diseases spread rapidly, simultaneously affecting a large number of animals in a region. Foot-and-mouth disease is an example of a disease that can be epizootic. Some diseases that are transmitted among animals also can be transmitted to humans. Such diseases are known as zoonotic diseases, a term derived from zoo and Greek nosos, ?disease.? Anthrax and rabies are examples of epizootic diseases that can also become zoonotic. | 2 |