👉 Infection, particularly infectious diseases, refers to the process by which pathogens—such as bacteria, viruses, fungi, or parasites—invade and multiply within a host organism, leading to illness. The "going in" phase involves the entry of these pathogens into the body, often through breaches in physical barriers like the skin or mucous membranes. Once inside, pathogens must survive and replicate, evading or overcoming the host's immune defenses. This can occur via various mechanisms, such as adhering to and colonizing tissues, producing toxins, or manipulating the host's cellular processes. The progression from initial entry to active infection involves complex interactions between the pathogen and the host's immune system, setting the stage for symptoms and potential complications.
