Plague

The term plague has been used to loosely define widespread, devastating diseases. Strictly, the term applies today to infection by the Pasteurella pestis (Yersinia pestis) bacterium. The disease may occur in three main forms: bubonic plague (most important diagnostic features of is swelling lymph nodes, particularly in the groin area), pneumonic plague (attacking the respiratory system) and septicemic plague (causing general blood poisoning). Many of its symptoms overlap with those of other infectious diseases. A 1°C increase in spring temperature and wetter summers may increase the carrier gerbil (rodent) population and can result in >50% increase of the prevalence of plague in Central Asia (Stenseth NC 13110). It used to be known also as the "black death" on account of the dark spots, appearing in largely symmetrical