Hideyo Noguchi's research on yellow fever (1918-1928) in the pre-electron microscopic era.

One of the low points in Hideyo Noguchi's career as a pioneer medical microbiologist was his investigations on yellow fever between 1918 and 1924 in Central and South America. His discovery that spirochete Leptospira icteroides was the causative pathogen of yellow fever was discredited in 1927. This paper evaluates the situation under which Noguchi conducted his experiments and assesses the causes which might have resulted in his erroneous interpretation in the pre-electron microscopic era. Even 60 years after Noguchi's untimely death, much remains to be known about the virulence of pathogenic strains of yellow fever.