👉 Infection, in the context of health and disease, refers to the process by which a pathogen—such as bacteria, viruses, fungi, or parasites—invades and establishes itself within a host organism, leading to illness. This interaction is facilitated when the pathogen breaches the body's natural barriers, such as the skin or mucous membranes, and begins to multiply or cause damage. The immune system then responds by mounting an attack to eliminate the invader; however, if the infection persists or overwhelms the immune response, it can result in disease. For example, a bacterial infection like strep throat involves the bacterium Streptococcus entering the body, typically through a sore throat, and multiplying, causing inflammation and symptoms. Understanding the dynamics of infection is crucial for developing treatments and preventive measures to combat diseases.
