👉 Infection is a biological process characterized by the invasion and multiplication of pathogens—such as bacteria, viruses, fungi, or parasites—within a host organism, leading to disease. Pathogens enter the body through various routes, including respiratory droplets, contaminated food or water, or direct contact. Once inside, they can replicate, causing damage to host tissues and triggering an immune response. The interaction between pathogens and the host's immune system determines the outcome: some infections are cleared by the immune system, while others persist, leading to chronic conditions or severe illness. Understanding infection involves studying the mechanisms of pathogen entry, replication, and evasion of host defenses, as well as the host's immune responses that combat these invaders. This knowledge is crucial for developing treatments, vaccines, and preventive measures to control infectious diseases.
