in 1914-1915, inada discovered the spirochete of infectious jaundice (weil's disease); and he developed a successful serum-therapy for the infection. he is credited with ground-breaking research on the weil's disease pathogen leptospirosis). the initial specimen material (stock of ictero no.1) which dr. inada isolated in 1914 has been preserved as a significant artifact in the history of medicine.