👉 Infection occurs when a pathogen, such as a bacterium, virus, fungus, or parasite, enters a host and begins to multiply or cause disease. This process starts with the pathogen attaching to specific receptors on the host's cells, often facilitated by surface proteins. Once attached, the pathogen can inject toxins, invade the cell, or evade the host's immune system. The host's immune response then attempts to combat the infection, but if the pathogen is successful, it can lead to symptoms and potential tissue damage. For example, a bacterial infection like strep throat involves bacteria adhering to throat cells and releasing toxins that inflame the area. Understanding the mechanisms of infection is crucial for developing treatments and preventive measures, such as antibiotics and vaccines, to protect against disease.
