👉 Infection occurs when a pathogen, such as a virus, bacterium, fungus, or parasite, enters a host's body and begins to multiply or cause harm. This process starts when the pathogen breaches the body's natural barriers, like the skin or mucous membranes, and then either adheres to, invades, or replicates within host cells. The immune system responds by attempting to eliminate the pathogen, but if the infection is successful, it can lead to disease. Understanding infection involves recognizing how pathogens enter, survive, and cause illness, as well as the body's defense mechanisms that work to combat them. Preventive measures, such as hygiene practices and vaccinations, aim to reduce the risk of infection by blocking entry points or enhancing immune responses.
