Many parasites hide inside our cells

Hiding protects them from our immune system.

Plasmodium invades liver cells and blood cells. It turns these cells into factories that help it to create more parasites. Toxoplasma is able to invade almost any cell in our body. It can also form cysts in muscle or the brain that the immune system cannot get inside.

Some parasites wear disguises to escape

Just as spies can disguise themselves to blend in, some parasites change the way they look to the immune system.  Plasmodium has 60 genes that allow it to alter the surface of the red blood cell it is hiding in. Trypanosomes have thousands of disguises in their wardrobe.  In the face of all these disguises, our immune systems struggle to keep up.

Outsmarting Our Defences

Once inside our bodies, the parasites meet with our next line of defence - the immune system. White blood cells patrol the body like guards, seeking out and destroying invading organisms. They can build antibodies: guided missiles that are programmed to precisely target and kill parasites. How do parasites survive this onslaught?

Learn more about the immune system

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Click on these images to learn more about each parasite