Pathogen

A pathogen is any microorganism that can cause disease in a host, such as humans, animals, or plants. This includes bacteria, viruses, fungi, and parasites. When a pathogen enters a host, it can disrupt normal functions and trigger the immune system's response, often leading to illness. Pathogens can be spread through various means, including direct contact, contaminated surfaces, or vectors like insects. Understanding pathogens is crucial for disease prevention, as measures such as vaccines, hygiene practices, and treatments aim to reduce their impact on health.