👉 Infections occur when pathogens, such as bacteria, viruses, fungi, or parasites, enter and multiply within a host's body, disrupting normal cellular functions and causing illness. The process begins when these microorganisms breach the body's defenses, often through breaches in the skin, mucous membranes, or via ingestion or inhalation. Once inside, pathogens can adhere to and invade host cells, replicate, and spread, leading to symptoms like inflammation, fever, and tissue damage. The immune system responds by mounting an attack, involving white blood cells and antibodies, but if the infection is severe or the pathogen is particularly virulent, it can overwhelm these defenses, resulting in disease. Understanding the mechanisms of infection is crucial for developing treatments and preventive measures, such as antibiotics for bacterial infections, antivirals for viral infections, and vaccines to bolster immunity.
