Total Organ Failure is a Tier 4 symptom. It causes catastrophic cell death of multiple tissue types, which causes body-wide organ failure and rapid death. It increases severity by 20%, and lethality by 25%.
Total Organ Failure is arguably one of the most lethal symptoms in the game and once evolved, it kills rapidly. Even wealthy countries will go down if enough people are infected. However, this extreme lethality increase is a double-edged sword. This symptom can backfire if not handled correctly.
Total Organ Failure should not be evolved before most of the world's population is already infected (for example: 100% of the population, including a fair chunk of Greenland and other hard-to-reach countries). It is commonly used to kill off the world's population rapidly, and is highly recommended to be used at the end of the game to end the game quickly. However, evolving it too early can often result in a game over, as all infected will likely die before they are able to infect all healthy people.
- This is as lethal as Cytokine storm and Vampiric Awakening, but not as lethal as Simian Flu symptom Total Brain Death or the Bioweapon ability Unlock Annihilate gene, making it the third (tied) most lethal symptom.
- This symptom loses much of its lethality in the scenario Artificial Organs, due to the organs are no longer organic and thus can barely have any effect.