👉 The highest level of infection, often referred to as "severe" or "systemic," occurs when an infectious agent—such as a virus, bacteria, or parasite—has spread extensively throughout the body, affecting multiple organs and systems. This widespread dissemination can lead to significant morbidity and mortality. For instance, in viral infections like Ebola or severe acute respiratory syndrome (SARS), the virus can invade vital organs such as the liver, kidneys, and lungs, causing acute organ failure and systemic inflammation. Similarly, bacterial infections like sepsis, where bacteria enter the bloodstream and trigger a massive immune response, can lead to widespread tissue damage and multi-organ dysfunction. In these cases, the infection is not just localized but has reached a critical point where it threatens the patient's life, necessitating intensive medical intervention to manage symptoms and support organ function until the infection can be effectively controlled or cleared.
