There are many parasites that can invade the human body. Some of them are blood borne, meaning they are found in the blood rather than in tissues. These parasites can be transmitted from one person to another through exposure to infected blood (e.g. through blood transfusion or the sharing of a needle). Some are transferred by insect carriers, such as mosquitos. Blood donors are screened for possible parasite exposure, and donations are screened for some blood borne parasites, but some do still get through.
Parasites are one of the nastiest things that nature has provided our beloved planet. They can manipulate the human brain, rewrite DNA and even turn a host into a living dead. Parasites range from one-celled organisms to relatively large tape worms. In this post, we look at the five most dangerous parasites known to man.