👉 Infection occurs when a pathogen, such as bacteria, viruses, fungi, or parasites, enters a host and begins to multiply, causing disease. This process involves the pathogen overcoming the host's immune defenses to establish itself within the body. Infection can be localized, affecting a specific area (like a sinus infection), or systemic, spreading throughout the body (such as sepsis). The body's response to infection includes inflammation, fever, and immune cell activation, which aim to eliminate the pathogen but can also cause tissue damage if not properly regulated. Understanding infection is crucial for developing effective treatments and preventive measures, such as antibiotics for bacterial infections and antiviral drugs for viral ones.
