About 350 million years ago, most of the North American continent was the flooded center of a continent hemmed in by mountainous borders. The sea receded and several ice ages followed. Glaciers covered even the Rocky Mountains. Twelve thousand years ago, the last glacier melted northward, leaving at approximate latitude 45 and longitude 114 a narrow valley approximately 10 miles from east to west and 50 miles from north to south. In this valley a river later named the Bitter Root River, flowed through northward until it joined another river cal1ed the Hell Gate River. The mountain ranges on the west and south of this valley are very high and rugged, reaching an altitude of 10,000 feet. Mt. LoLo the highest peak is perpetually capped by snow. The foothills rise suddenly on the west and there was once considerable timber in these regions, wild animals and ticks abounded. On the east and north the mountains are of low altitude and the slope of the foothills is gradual. The tick population was considerably smaller on these slopes. The valley itself was formerly the bottom of a huge lake and its soil was wonderfully fertile. In some places the subsoil extended down forty feet. Several tribes of Indians were the so1e inhabitants of this region until about 1870. The Indians discovered here the bitter root plant which covered the landscape each June with its pink blossoms only to disappear within a few weeks. The Indians used the roots of this plant for medicinal purposes and they named the river and the valley after this plant.
The Indian tribes believed that in the spring of the year the Bitter Root Valley was visited by evil spirits and it was particularly hazardous at this time to go into certain canyons especially LoLo Canyon. The precise nature of the danger associated with the evil spirits is recorded. There are no records of serious acute febrile i11nesses among the Indians, which would suggest Spotted Fever.
History records that after the Bitter Root Valley was evacuated by the Indians and settled by white men about 1890, a few cases of “black measles”, almost all of them fatal, occurred every spring and summer. The settlers recognized that as the first warm days of spring arrived ticks appeared by the millions on the western slopes. They were found on all animals roaming in the fields and also on plants, especially hay. Some of the earlier settlers had the insight to associate the appearance of ticks with a disease and so named the disease Tick Fever. Another name given to it was Spotted Fever which we now call Rocky Mountain Spotted Fever.
The first detailed description of Rocky Mountain Spotted Fever was published in 1899 by Dr. Edward E. Maxey of Boise City, Idaho. He described a type of spotted fever occurring in southern Idaho on the western side of the Bitter Root Mountain among the sheepherders who worked along the southern foothills of the Boise Mountain.
A more deadly type of spotted fever characteristic of the Bitter Root Valley was described in July 1902 by McCullough. These cases occurred only from March through September and were most numerous in April, May and June. Both sexes and all ages were subject to the disease but it was most common in the males from 21 to 40 and females 11 to 40. A very large percentage of the patients lived on farms or were connected with a lumbering industry. It was apparent that cases of spotted fever were much more numerous and much less severe in southern Idaho than in the Bitter Root Valley of Montana; the mortality in Idaho being about 3 percent and about 75 per cent in the Bitter Root Valley. Geologically the two infected areas communicate through LoLo Canyon passing the Bitter Root Mountains where the most virulent type of disease occurs.
The early clinical descriptions of the spotted fever were so complete and so accurate that nothing significant has been added to them subsequently. The disease occurs wholly in the spring, first cases appear in March after the snow melts and the incidence reaches its maximum during May and June with only a few cases during July.
The incubation period seems to range from three to twelve days. The onset of the disease is accompanied by a chill or by a few days of malaise with anorexia and chilly sensations. From the beginning of the clinical symptoms the patient has severe general pains referred to the bones, muscles, back and joints. The pains are most severe in the calf muscles, large joints and the lumbar region of the back. Headache is common and usually severe. Most patients are ill enough to be bedridden on the second day of the symptoms. A very common sign is a hacking cough without production of sputum. The spleen is uniformly enlarged and tender. Before the initial chill the patient usually has only minimal fever in the evening. After the chill the temperature rises fairly rapidly reaching 102 to 104 degrees on the second day and continuing to rise gradually to a maximum of 104 to 105 degrees in the second week. In severe cases of the type seen in the Bitter Root Valley, the temperature reaches 106 to 107 degrees and may remain this high until death. For those who recover, the disease lasts for approximately three to four weeks. Death occurs most commonly between the sixth and twelfth day of the clinical disease.
A typical skin eruption occurs between the third and fifth day of a disease. The eruption appears first as a reddish mark. The rash first consists of rose-colored macules, the spots soon become deep red or purplish and increase in size. After they have been present for several days, the spots no longer exist and the skin assumes a glazed appearance of the second week and the thighs may show a particular dusky reddish or bluish mottling. The rash begins to disappear with the subsidence of fever but the size of the petechiae becoming demonstrable when the skin is chilled or after strenuous exercise or a hot bath. The central nervous system may be involved and in severe cases the patient usually becomes delirious during the height of the disease. There are no frequent complications of the disease.
In March 1901 the Montana State Board of Health decided that something should be done about spotted fever. The problem was turned over to Dr. Longeway, head of the Mayo Foundation who arrived in Missoula from Minnesota to start research on anatomic phases of Rocky Mountain Fever.
His studies were essentially unproductive although the endemic nature of the disease was established. Great confusion was engendered by disagreement concerning the possible role of the wood tick in the transmission of the disease.
This was the situation in 1906 when unexpected help appeared in the person of Dr. Howard Ricketts who came to Montana from the University of Chicago of his own accord and volunteered to undertake a study of the disease. Because of the question as to whether or not ticks produced some toxic agent, it was possible for Dr. Ricketts to consider the tick theory as a third person without prejudice for or against it. To Dr. Ricketts it was a magnificent opportunity to investigate a disease whose etiology was unknown and clouded by scientific argument.
Dr. Ricketts was born in Findlay, Ohio on February 9, 1871. He began his college career at Northwestern University in 1890. In 1892 the family moved to Lincoln, Nebraska. This move to the west was occasioned by the fact that his father was a grain dealer who felt that opportunities would be greater in the western environment. Dr. Ricketts entered as a junior transfer student from Northwestern University and graduated from the University of Nebraska in the class of 1894.
He was slight of build, never ruddy of complexion, quiet, thoughtful. As a student he had many friends and was very highly respected. He volunteered to join the football squad and was a very fierce competitor. Although he never made the first team he was a valiant and conscientious second stringer who never missed practice and took a great deal of physical punishment. At that time one of the prides of the University was the ROTC Cadet Battalion, with Blackjack John Pershing as commandant. Dr. Ricketts was a Platoon Commander in the ROTC and was considered by General Pershing to be a meticulous and excellent student of military affairs. As a student at the University of Nebraska, Dr. Ricketts took part in dramatics and in the activities of the Glee Club.
Although the faculty of Nebraska was much stronger in science than in the classics, Dr. Ricketts' experience as an undergraduate at Northwestern University where he studied the classics and other types of ancient learning, had substantial impact on his work at the University of Nebraska. For reasons no one ever understood, although he was an excellent student, he was not elected to Phi Beta Kappa.
The financial panic of 1893 hit the west with a paralyzing blow. Corn was selling for as little as six cents a bushel. Dr. Ricketts’ father suffered among the thousands of others and when it came time for Howard to enter the medical school his resources were slender indeed. At that critical time he received encouragement and moral support from a girl that he had known on the campus at Northwestern. He returned to Northwestern as a freshman medical student. During his four years of medical school he completed his studies with honor, engaging in all kinds of extracurricular activities related to financing his education. For a period he slept in a physician's office, answered night calls, helped do dressings, almost anything to earn an honest dollar. There is little question but what there was an impact upon his health resulting from this very strenuous way of living.
Upon graduation in 1897 he served as an intern in the Cook County Hospital in Chicago. Following his internship, he became a fellow in cutaneous pathology at the Rush Medical College and continued in this capacity for two years. During part of this time he also worked in the Dermatology Clinic.
In 1900 he married his college sweetheart, Myra Tubbs who supported him in his work with rare devotion, keen interest and steady encouragement. This marriage was blessed with two children one son and one daughter.
In 1901 Dr. Ricketts had the opportunity to visit several European 1aboratories for a year of study. At the end of this year he returned to the University of Chicago as an instructor in the newly founded Department of Pathology and Bacteriology. In due course, he became an Assistant Professor. His academic career was climaxed in the early part of 1910 when he was offered and accepted the Chair of Pathology at the University of Pennsylvania School of Medicine. Unfortunately, he was never able to fill this chair.
Dr. Ricketts was a modest and unassuming man of great determination and of the highest character. He was loyal and generous, earnest and genuine in all his doing and had a personality of unusual and winning charm. His associates in the medical school and from his fellowship days who knew him well knew his ability and his distinct fondness for the day's work, and all looked to him for more than ordinary achievement.
He deliberately turned away from all the allurements of active medical practice and decided to devote himself to teaching and investigation in Pathology. He had early become possessed of noble ideas, had a genuine love for the search after truth which abided with him and gave him a very high conception of all his duties and placed a very special stamp upon his work. His instinct for research continued to grow and growing stronger it carried him farther and farther, and in due time the University freely and in special ways, promoted the work in which he was to accomplish such large results.
During the few short years given to him in research he advanced farther than many realized at the moment and it is now apparent that he broke open many paths for future progress. In his early days in research he worked in the area of Blastomycosis, and immunological problems. His investigations were marked by thoroughness, directness and by clear and forceful reasoning. It was his brilliant work on Rocky Mountain Spotted Fever however, in which Dr. Ricketts fully revealed himself as an investigator of the first rank. He began the study of this fever in the spring of 1906 as a sort of a past time during an enforced holiday because of poor health related to overwork. During the first year he made several very critical observations and I would like to read to you the chronological listing of his activities during that year. His such findings were that the disease was communicable to lower animals and that a certain tick which occurs naturally in the area by its bite transmits the disease from the sick to the healthy animal. Those observations opened a new field and from that time on, he devoted himself untiringly to the investigations of the many problems that arose one after another as the work went on, both in the laboratory and in the field.
As one examines the various stages in the progress of his very active work, it becomes very clear that Dr. Ricketts not only was gifted with imagination so that he could see and trace the various lines along which the solution of a problem might be sought, but that he also possessed in full measure the capacity for that very hard accurate patient work so necessary for the very difficult task of finding the one true answer.
In 1909 he decided to undertake a study of typhus fever in Mexico. He had noted many similarities between typhus and Rocky Mountain Fever, and hoped that the experience gained in Montana would enable him to make a similar contribution in the case of Typhus.
He began work in the fall of 1909 in Mexico City and by April, 1910 had produced significant results. He had discovered the vector responsible and he was able to demonstrate the presence of the small rods in the blood of patients and in the insect vector. In late April he became ill with typhus, and reassuring his wife by mail until the last, died 3 May, 1910 at the age of thirty-nine.
The truly significant achievements he made were to:
1. Lay open the secrets of different orders of living things concerned in the transmission and etiology of disease.
2. He developed information on the hereditary nature of infection in ticks.
3. He demonstrated the role of other animals in the cyclic nature of a disease entity caused by a family of organisms named after him in his honor.
4. He proved the mechanisms which are responsible for the propagation and endemic nature of diseases transmitted by insect vectors
Ricketts, H. T. J.A.M.A., 47:33, 1906.
Ricketts, H. T. J.A.M.A., 47:358, 1906.
Ricketts, H. T. J. Infect. Dis. 4:141, 1907.
Abituary, Howard Taylor Ricketts, J.A.M.A., 54:19l0.
Editorial, Lancet 1:540, 1911.
Hektoen, L. Quart. Bull. Univ. Med. Sch., 19:2, 1945.
Aikawa, J. K. Rocky Mountain Spotted Fever, Charles C. Thomas, Publisher, 1966.
McMurry, J. F. Oklahoma State Medical Assn. Jour., 59:165, 1966.