The plague has killed millions of people in history, especially in the 14th and 17th centuries. In 14th century Europe, the great pandemic resulted in twenty-five million deaths. The plague is still a problem to society, with some 5,000 cases annually. There are many bacterial diseases that are transmitted by some form of fecal contamination of food or water, either directly or indirectly. House flies are a primary agent in transmitting these diseases, and do so mechanically.
Cholera is another enteric disease of great importance.
Shigella, causing dysentery and diarrhea, and Escherichia coli, causing urogenital and intestinal infections, are widespread enteric diseases. This disease is caused by an arachnid, the deer tick, which carries a bacterium called Borrelia bugdorferi. When a person or warm-blooded mammal is bitten, the bacterium enters the bloodstream, and Lyme disease may occur. The disease was first described in New England and the mid-Atlantic states, but is now known from all of the Northern Hemisphere. This disease is also known as African Trypanosomiasis.