Doing so induced high-grade (103 °F, 39.4 °C or above) fever that was easily sustainable to eradicate invading spirochaetal bacterium Treponema pallidum, the pathogen responsible for syphilitic infection.[2][3] Successive rounds of treatment were required to fully eradicate the infectious bacteria, while simultaneously using quinine to treat the malaria infection.[2] Management of the fevers was risky as malaria fevers can sometimes cause death, but syphilis was a proliferate and terminal disease at the time with no other viable treatment.[2] This procedure was used to treat syphilis until penicillin was found to be a safer, more effective measure in the 1940s.[3]