From the 1920s until the 1950s, prior to the introduction of penicillin, malaria-induced fevers were used as a treatment for neurosyphilis—the spiking fevers associated with malaria killed the bacteria that caused the syphilitic infection.
A new essay appearing online ahead of print in the Hastings Center Report explores this chapter in the history of U.S. medicine during which physicians also inoculated nonsyphilitic patients with malaria, using them as reservoirs to facilitate the treatment of others.