Rickettsia Rickettsii - History

History

Rocky Mountain spotted fever first emerged in the Idaho Valley in 1896. At that time, not much information was known about the disease; it was originally called Black Measles because patients had a characteristic spotted rash appearance throughout their body.

Howard Ricketts (1871–1910) was an American pathologist and infectious disease researcher who was the first to identify and study the organism that causes Rocky Mountain spotted fever. He received his undergraduate degree in zoology from the University of Nebraska and his medical degree from Northwestern University School of Medicine. Ricketts completed his internship at Cook County Hospital in Chicago, IL, followed by a fellowship in pathology and cutaneous diseases at Rush Medical College.

In 1902, Ricketts became the associate professor of pathology at the University of Chicago. The trademark rash, which first appeared in the Idaho Valley, now began to slowly emerge in the Bitterroot Valley region, a highly influential area in western Montana and had an 80-90% mortality rate. During his tenure as associate professor, Ricketts was funded and recruited by the University of Chicago, the State of Montana, and the American Medical Association to conduct research on Rocky Mountain spotted fever.

His research entailed interviewing victims of the disease and collecting and studying infected animals. He was also known to inject himself with pathogens to measure its effects.

Ricketts was also known for his research on typhus, which was very similar to spotted fever. Ironically, days after isolating the organism that he believed to cause typhus, he died. It was speculated that his death was likely caused from an insect bite.

S. Burt Wolbach is credited for the first detailed description of the etiologic agent in 1919. He clearly recognized it as an intracellular bacterium which was seen most frequently in endothelial cells. He was struck by the fact that in the tick, and also in mammalian cells, the microorganism was intranuclear. The nucleus was often completely filled with minute particles and often was distended. Although Wolbach recognized its similarity to the agent of typhus and tsutsugamushi fever (scrub typhus), he did not regard the designation 'rickettsia' as appropriate. He proposed the name Dermacentroxenus rickettsi. Dr. Emile Brumpt felt that the etiologic agent of RMSF, despite some uncertainty about its properties, belonged in the genus Rickettsia and in 1922 proposed the name Rickettsia rickettsii.