What causes ringworm?

Ringworm is caused by a type of fungus, specifically dermatophytes, which thrive on keratin found in skin, hair, and nails. These fungi create circular or ring-shaped rashes on the skin, which is how the name "ringworm" originated, despite having nothing to do with worms. The infection is highly contagious and can spread through direct contact with an infected person, animal, or even contaminated surfaces.

The other options do not accurately describe the causative agent of ringworm. Bacteria and viruses are different types of pathogens; while they can cause various infections, neither is responsible for ringworm. Similarly, although plant parasites can affect other living organisms, they do not cause fungal infections in humans. Insects may transmit certain diseases but are not involved in the etiology of ringworm. Understanding that ringworm is specifically a fungal infection is crucial for both treatment and prevention strategies.