What are pathogens?

Pathogens are disease-causing microorganisms or biological agents that invade host organisms and disrupt normal physiological functions, leading to illness or infection. They include bacteria, viruses, fungi, protozoa, and parasitic worms, each capable of causing a wide range of diseases in humans, animals, and plants. Pathogens spread through various routes including air, water, food, direct contact, insect vectors, and contaminated surfaces.

The severity of diseases caused by pathogens varies widely—from mild infections like the common cold to life-threatening conditions such as tuberculosis, malaria, and cholera. The human immune system constantly works to identify and eliminate pathogens, but when overwhelmed or compromised, medical intervention through antibiotics, antivirals, or vaccines becomes necessary. Proper hygiene, sanitation, vaccination programs, and safe food handling practices are essential preventive measures that reduce pathogen transmission and protect public health.