Early "Bugologists" Instrumental in Fight Against
Rocky Mountain Spotted Fever

By Tana Kappel

12/21/98 BOZEMAN --  In the early 1900s, each spring brought fear to the Bitterroot Valley of western Montana. A mysterious disease was killing people, typically those who spent considerable time out of doors.

The disease, dubbed Rocky Mountain spotted fever, caused a high fever and splotches on the skin. In 1899 and 1900, there were 35 cases of the disease in the valley. Few who contracted it survived.

The disease took on an urgency, according to Esther Gaskins Price, author of "Fighting Spotted Fever in the Rockies." Her book quotes Montana Governor Joseph Toole admonishing his first Secretary of Health in 1901: "You must do something about spotted fever.... I have just had an appeal from the people of the Bitter Root."

Over the next two decades, a team of researchers heeded the call, risking their lives -- and in a few cases giving their lives -- to develop knowledge and treatments that would bring the disease under control. A central figure in the fight was Robert A. Cooley, the first head of the Montana State College Department of Entomology.

Understanding spotted fever was no simple matter. Howard Taylor Ricketts, a University of Chicago medical researcher, began the under-funded investigation in 1906 in a lab tent in Missoula. He believed that infected people and animals carried an organism in their blood.

Based on his own limited studies with ticks and numerous other studies linking insects to diseases, he was convinced that ticks were carriers. "Insect vectors were the subject of intense scrutiny at the time," says Montana State University-Bozeman history professor Pierce Mullen. "For example, people were very concerned about mosquitoes. They were carriers of yellow fever which killed many troops during the Spanish/American War and the building of the Panama Canal."

To prove the tick-spotted fever connection, Ricketts enlisted the help of Cooley and a cadre of eager MSC students, some of whom eventually contracted the disease and died. The Montana Ag Experiment Station also authorized funds to support the cause.

Still, Cooley was fighting an uphill battle. The head of the State Board of Health, a physician, resented what he and other medical authorities considered an "intrusion" by "mere bugologists" into public health issues.

In addition, the people in the Bitterroot were opposed to the idea of a tick carrying the disease organism. In a statement on file at the MSU-Bozeman library archives, Cooley wrote: "They didn't want the cause of spotted fever to be the tick. They felt it would prevent the development of the Valley if this were true."

Nonetheless, Cooley pushed ahead, with the support of the state Board of Entomology which he helped found in 1913. In 1918, the board established the Rocky Mountain Spotted Fever Lab in Hamilton. At first an old schoolhouse, it eventually became the setting for much of the dramatic research on spotted fever and many other diseases. In 1934, it became a federal research facility and one of the most important labs in the medical entomology field.

It was Cooley's organizational ability, says Mullen, that made it possible for the state and federal government to devote resources and people to tackle this problem.

His scientific skills were considerable as well. Cooley and crew documented the life cycle and biology of the wood tick -- as well as other insects. Wood ticks require a blood meal from three different hosts to complete their development. When they hatch, they attach to ground squirrels or similarly sized animals in order to pass to the nymph stage.

Nymphs will seek a dog-sized host and, once they've gorged, will become adults. The adults will seek larger animals such as humans or cattle. This knowledge was significant, says Greg Johnson, current head of the MSU-Bozeman Entomology Department, because it meant that control efforts needed to be targeted at the adult tick which transmitted the disease.

As a result, early control efforts involved dipping livestock in a solution poisonous to the ticks. They also tried to teach people that simple hygiene, searching the body for ticks, could  save lives, says Mullen.

Though worthwhile, these efforts weren't enough. The disease, once thought to be isolated in the Bitterroot Valley, had spread to 28 eastern Montana counties by 1920.

So, in 1920 the effort was intensified when R. R. Parker, a Massachusetts State College entomologist, was enlisted to help Cooley. Parker demonstrated that rabbit ticks were carriers of the virus and could transmit it.
The breakthrough of the year, though, was the discovery of the disease organism by a Harvard researcher, one Dr. Wolbach. He dubbed it Dermacentroxenus rickettsi Wolbach, a name that also gave credit to Howard Ricketts, who was on the track of this microorganism when he died in Mexico in 1909 at age 39 -- a victim of typhus. Ricketts had joined a research team in a typhus ward in a Mexico hospital, and found that the blood of typhus patients contained microorganisms similar to that of patients with spotted fever.

Ricketts knew that the microbe "causing the Bitterroot enigma was a cousin of that which caused typhus, the scourge of mankind through history," says Mullen. But equally astounding was Ricketts' work that established the existence of a third class of disease-causing organisms. The Rickettsia organism was like a virus -- it needed to live parasitically -- but in form it resembled bacteria. Because it was difficult to grow outside living tissue, it was a challenge to study.

Meanwhile, back at the lab in Hamilton, R. R. Spencer of the U.S. Public Health Service and Parker decided to grind up ticks and inject them into guinea pigs. The results were puzzling to the scientists; none of the guinea pigs came down with spotted fever.

According to Price, the researchers speculated that perhaps a blood meal on an animal host was essential to cultivating the spotted fever virus.

       "The more they thought about it, the more logical it seemed and they were all excited now."

By coincidence, they were presented with a perfect opportunity to test their thesis. A research assistant, George Cowan, known for his fearless work in the field gathering ticks and hosts, had just returned from a hunting trip with a mountain goat he had shot. On the goat were hoards of ticks.

The researchers "noticed that 'these damn ticks are fat as hell!' They'd had their blood meal," wrote Price.

The researchers ground up the ticks and injected them into guinea pigs, all five of which died of spotted fever. Though these guinea pigs had had ticks on them before, the ticks had been pulled off before they'd gorged on blood and activated the virus.

This discovery led to the development of a vaccine. The researchers had found that when ticks first come out of hibernation, they frequently contain the virus in a phase that produces a low grade infection of spotted fever, and that low grade infection immunized lab animals.

But these discoveries had a cost. Researcher Art McCray contracted spotted fever and died in 1919, followed by Bill Gittenger, a lab research assistant and MSC entomology graduate, in 1922. Spotted fever also claimed the lives of Cowan, in 1924, and Albert Kerlee in 1928.
By 1925 the experimental vaccine had been developed, though it had some uncomfortable side effects. The researchers decided to vaccinate themselves, along with some local farmers, stockmen and others likely to come in contact with ticks.

Though expensive -- $20 per shot -- the vaccine cut the death rate from 80 percent to less than 19 percent in the Bitterroot. And in eastern Montana and south-central Idaho, where the milder form occurred, vaccination practically eliminated the disease.

Cooley, meanwhile, was also searching for parasites of the tick. He traveled to France, and later to Africa in search of big game, in hopes of plucking live ticks from their bodies. He got ticks and parasites, but they didn't survive the Montana winters. And the researchers back at the lab were more focused on developing a vaccine than studying parasites.

By the mid-1920s, the disease was no longer a threat to life, says Mullen. But today, Rocky Mountain spotted fever is still with us. Most of the recent cases have occurred in the Piedmont area of the east cost, "where housing developments are pushing into the brush," says Mullen.

In Montana the disease afflicts about three to five people every year, according to Jim Murphy, a health specialist with the Department of Public Health and Human Services. "For some people, it is still life threatening," but death is uncommon. Diagnosis involves a blood test, and antibiotics are used to control it. Though more vaccine work is under development, no vaccine is currently licensed.

The efforts of the early researchers extended way beyond spotted fever. Robert Cooley, notes Price, had demonstrated that cooperation between entomologists and physicians could provide "a real pathway to progress." The result was a much broader understanding of such diseases as tularemia, typhus, scrub typhus, malaria and Q-fever -- knowledge that helped "protect our troops in both the Atlantic and Pacific theaters during the war."

"These guys were clear-eyed and energetic," says Mullen. "They saw a problem and they tackled it."

Send questions or comments to Tana Kappel and Carol Flaherty, MSU Communications Services, Bozeman, MT 59717 or to Flaherty with this link: carolf@montana.edu.

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