👉 Infection is a process where a pathogen, such as a virus, bacterium, fungus, or parasite, invades and takes control of a host cell or organism, leading to disease. The mechanism begins when the pathogen enters the host through various routes, like inhalation, ingestion, or skin contact. Once inside, the pathogen must evade or overcome the host's immune defenses. For example, viruses may bind to specific receptors on host cells and inject their genetic material, hijacking the cell's machinery to replicate. Bacteria can produce toxins or form biofilms to survive and spread. The replication of the pathogen often triggers an immune response, but if the infection is successful, it can cause damage to tissues and organs, resulting in symptoms of illness. This interaction between the pathogen and host is a complex battle that determines the outcome, ranging from mild infection to severe disease or even death.
