Part 1 of Essay
Since the reign of Emperor Justinian in 542 A.D., man has one unwelcome organism along for the ride, Yersinia pestis. This is the bacterium more commonly know as the Black Death, . Plague is divided into three biotypes, each associated with one of three major pandemics occurring in history. Each of these biotypes are then ....

Part 2 of Essay
.... of pneumonic plague with 31 fatalities. Since then there have been around 16 cases a year in the United States, most connected with rock squirrels and its common flea Oropsylla montana. The most dangerous type of plague is pneumonic. It can be spread through aerosol droplets released through coughs, sneezes, or through fluid contact. It may also become a secondary result of a case of untreated bubonic or septicemic plague. Although not as common as the bubonic strain, it is more deadly. It has an untreated mortal ....