👉 Infection is a biological process where pathogens, such as bacteria, viruses, fungi, or parasites, invade and multiply within a host organism, leading to disease. This occurs when these microorganisms breach the body's natural barriers, like the skin or mucous membranes, and establish themselves in tissues or organs. The interaction between the pathogen and the host's immune system is crucial; while the immune system typically fights off invaders, some pathogens can evade or manipulate this response, causing harm. Infection can range from mild, such as a cold, to severe, like sepsis or pneumonia, depending on the pathogen's virulence and the host's overall health. Understanding infection involves recognizing how these pathogens cause disease and how the body's defenses work to combat them, often through the development of symptoms and the immune response.
