👉 Infection is a biological process where a pathogen, such as a bacterium, virus, fungus, or parasite, invades and establishes itself within a host organism, disrupting normal cellular functions and leading to disease. Despite the body's immune defenses, which typically recognize and combat these invaders, pathogens can evade or overcome these mechanisms, allowing them to multiply and spread. This invasion can cause inflammation, tissue damage, and systemic effects, depending on the pathogen and the site of infection. For example, a bacterial infection might lead to pneumonia, while a viral infection could result in the common cold or more severe conditions like influenza. The severity and outcome of an infection depend on various factors, including the host's immune response, the pathogen's virulence, and environmental conditions. Understanding the mechanisms of infection is crucial for developing effective treatments and preventive measures.
