Blood plague has tightened its grip on State of Decay 2, creating new challenges for players to tackle, and introducing tempting new rewards in Update 25. Plague hearts are now surrounded by an area of malevolent influence, known as plague territory. Bases and outposts within these spheres cannot be claimed until the heart has been defeated. However, the rewards balance the risks, as enhanced outposts offer increased resources and even additional community skills.

Source: N4G PC Blood Plague Takes Over State of Decay 2