Man, monkeys and malaria

Bizarre though it may now seem, in the last century a whole series of exper iments was conducted that involved injecting fresh monkey blood into human volunteers or patients. The reasons, valid at the time, were either to trea t neurosyphilis with a relatively benign simian malaria infection (so-calle d pyrogen therapy), or to establish which monkey malaria species were poten tial zoonotic reservoirs of infection that then may have interfered with ma laria eradication campaigns. Although direct inoculation of fresh blood is the most effective way of retroviruses as well as malaria parasites crossin g the species barrier, this hypothesis was never taken up or researched. Un likely, but not disproved, it is important to remember some of the more haz ardous experiments that were done in good faith, too long ago to be recorde d on electronic databases.