👉 Infection is a biological process where a pathogen, such as a virus, bacterium, fungus, or parasite, invades and takes over a host organism, typically causing disease. This occurs when the pathogen enters the body through various routes—like the respiratory tract, skin, or digestive system—and begins to multiply or cause damage to host cells. The immune system then responds, attempting to eliminate the invader; however, if the pathogen is highly virulent or the host's defenses are weakened, infection can lead to illness. Infection can manifest in different ways, from mild symptoms like a cold to severe conditions such as sepsis or organ failure, depending on the pathogen and the host's overall health. Understanding infection is crucial for developing treatments and preventive measures, including vaccines and antibiotics.
