<unk>  is one of the three main forms of plague. It is caused by Yersinia pestis, a gram-negative species of bacterium.<unk>  is a life-threatening infection of the blood, most commonly spread by bites from infected fleas. Like some other forms of gram-negative sepsis,<unk>  can cause disseminated intravascular coagulation, and is almost always fatal when untreated. The other varieties of the plague are bubonic and pneumonic plague.
Septicemic plague
Urban plague
Bubonic plague
Hittite plague
Metal fume fever
Sylvatic plague
Tomato fever
Pneumonic plague