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Staying healthy

spherical shaped virus showing a cross-section through the core

A hepatitis C virus showing DNA enclosed in a protein coat.

Pathogens are microorganisms that cause disease. The body has several defence mechanisms to prevent pathogens from entering the body and reproducing there. The immune system can destroy pathogens that manage to enter the body. New medical treatments and drugs must be tested before their use.


Pathogens are organismsorganisms: living entities - ie animals, plants or microorganisms. that cause disease. They include microorganisms such as bacteria, viruses, fungi and protozoa. The table shows some of the diseases they cause.

Diseases pathogens cause

virusesinfluenza (flu)
fungiathlete’s foot

Back to Understanding organisms index

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