Canyon Creek Schoolhouse Laboratory 100^th Anniversary

Research Before the Canyon Creek Schoolhouse Laboratory

One of the first questions that arises around a disease is: What causes it? How Rocky Mountain spotted fever (RMSF) progressed was already known: people got a fever, developed a spotted rash, and quite often died. In one specific area, the Bitterroot Valley of Montana, the death rate was around 80%. In 1902, Montana acted to protect its citizens, requesting the aid of scientists from the University of Minnesota and from the U.S. Public Health Service.

Dr. William Chowning and Dr. Louis Wilson arrived in the Bitterroot Valley in the spring of 1902. Both men were pathologists, who studied the causes and effects of diseases, often by using tissue samples.

Because RMSF occurred only in certain areas and only during the spring, and because the death rate from it also varied from area to area, they realized that RMSF was not a contagious infectious disease; it was most likely a disease carried by a living vector. A vector transmits a bacteria or a parasite which causes a disease from one animal to another—in this case, to humans. 

Dr. Julius O. Cobb, a U.S. Public Health Service official, was also asked to investigate the disease, but by the time he got to Montana in June 1902, he found that Chowning and Wilson had done the work. He wrote:     

“These gentlemen have gone so far in their experimental work as to be able to show that an entirely new disease has been encountered, and one never before described…. As hundreds of persons are bitten with ticks throughout this portion of the State, and as a great many are bitten by ticks from this infected locality and comparatively few contract the disease, it was fair to presume that all ticks did not harbor the parasite. This naturally led them to the presumption that the host was not the tick, but some animal infested by ticks…. Clinically, the disease is very odd….

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• “The So-called ‘Spotted Fever’ of the Rocky Mountains—A new disease in Bitterroot Valley, Montana,” J. O. Cobb, Public Health Reports (1896-1970), Vol. 17, No. 33 (August 15, 1902), pp. 1868-1870.) (497 kB)

Chowning and Wilson thought that the tick was a vector for RMSF, but they weren’t able to prove their theory beyond the shadow of a doubt. They couldn’t isolate what pathogen the ticks were carrying for two reasons: the knowledge that they did not have, and the knowledge that they thought they had. The knowledge that they did not have was the concept of viruses or virology; they couldn’t look for what they didn’t know existed.

The knowledge that Wilson, Chowning, and Cobb thought they had was an incorrect theory put forth by Dr. Charles Stiles, well-known to researchers of the time as a founder of medical zoology. Stiles taught that diseases which were accidentally spread on the feet of insects (for example, house flies picking up typhoid germs in outhouses and transmitting them to food on which they land) would all be bacterial diseases. Stiles believed that diseases that were transmitted only by insect bites would all be protozoan diseases.  Wilson and Chowning were looking for the wrong thing: a protozoa.

Dr. William M. Chowning worked at the University of Minnesota when he came to the Bitterroot Valley to investigate RMSF in 1902. He eventually began his own private medical practice.

Dr. Louis B. Wilson was also a pathologist at the University of Minnesota when he came to the Bitterroot Valley, Montana in the spring of 1902, to investigate the causes of RMSF. Wilson eventually became director of the Mayo Clinic in Rochester, Minnesota.