👉 Infection, particularly from pathogens like bacteria, viruses, fungi, or parasites, occurs when these microorganisms breach the body's natural defenses and establish themselves within host tissues or fluids. The process begins with the pathogen entering the body through various routes, such as the respiratory tract, skin, or digestive system. Once inside, the pathogen must evade or overcome the host's immune response, which includes physical barriers like skin and mucous membranes, as well as cellular defenses like phagocytes and antibodies. If successful, the pathogen can multiply and cause disease by disrupting normal cellular functions, triggering inflammation, or directly damaging tissues. Understanding infection is crucial for developing effective treatments and preventive measures, such as antibiotics, antivirals, vaccines, and hygiene practices, to mitigate its impact on human health.
