👉 Infection is a biological process where a pathogen, such as a virus, bacterium, or parasite, enters a host organism and begins to multiply, often causing harm or disease. Initially, the pathogen must attach to specific receptors on the host cell surface, then invade or enter the cell. Once inside, the pathogen hijacks the host's cellular machinery to replicate itself, leading to an overgrowth that can disrupt normal bodily functions. This replication can trigger an immune response, where the body's defense mechanisms attempt to eliminate the invader. However, if the infection is severe or the host's defenses are compromised, the pathogen can establish itself, leading to symptoms and potential long-term health issues. The transformation from a harmless microbe to a cause of illness involves a complex interplay between the pathogen's virulence factors and the host's immune system.
