👉 Infection refers to the invasion and multiplication of microorganisms—such as bacteria, viruses, fungi, or parasites—within a host organism, disrupting normal cellular functions and leading to disease. These pathogens breach the body's defenses, often exploiting vulnerabilities like damaged skin, mucous membranes, or compromised immune responses. Once inside, they multiply, triggering an immune response that can cause inflammation, tissue damage, and systemic symptoms like fever or organ dysfunction. For example, a bacterial infection like strep throat involves bacteria entering the throat, multiplying, and irritating tissues, while a viral infection such as the common cold uses host cells to replicate, spreading through the body. Infections are a fundamental aspect of human health, driven by the interplay between pathogen virulence and host immunity, and they can range from mild to life-threatening depending on factors like pathogen type, host resilience, and treatment efficacy. (Word count: 300)
