👉 Infections are a fundamental aspect of biological systems, representing the invasion and proliferation of pathogens—such as bacteria, viruses, fungi, or parasites—within a host organism. These pathogens exploit the host's cellular machinery to replicate and spread, often causing disease through direct damage, immune system evasion, or disruption of normal physiological functions. Infections can be categorized into acute (short-lived) and chronic (long-lasting) based on their duration and the pathogen's ability to persist. The body's response to infection involves both innate immunity, which provides immediate but non-specific defense, and adaptive immunity, which develops a targeted response over time, involving specialized cells and antibodies. Understanding infection dynamics is crucial for developing treatments and preventive measures, such as antibiotics for bacterial infections, antivirals for viral diseases, and vaccines to bolster immune defenses.
