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Ideas | Allen Steere

Lyme disease: How we discovered it and where we go from here

The deer tick is now known to transmit five other recently identified infectious agents. Clearly, Lyme disease and other tick-borne infections take an enormous toll on the public health of any affected community.Cape Cod Cooperative Extension

Beginning in late 1975, as a fellow in rheumatology at Yale and a former CDC investigator, I led an investigation of a cluster of children in Lyme, Conn., many of whom had been diagnosed with juvenile rheumatoid arthritis, or JRA. Yet, on some roads, as many as 1 in 10 children who lived there had this illness, greatly exceeding the expected frequency.

Although the clinical features of the children’s illnesses seemed like JRA, evaluation of the case clusters suggested a radically different possibility: that they had a previously unrecognized insect-transmitted illness. As a working moniker, we said the children had “Lyme arthritis.”


Some parents recalled their children had developed an unusual, large expanding red skin lesion during the summer, weeks or months prior to the onset of arthritis, which they thought was an insect bite. The following summer, we set out to find people in the Lyme area who had experienced this unusual skin lesion. Our plan was to evaluate each patient in our clinic over a 1-to-2 year period to learn whether they would develop arthritis. Indeed, three-quarters of the patients with this skin lesion, both children and adults, developed arthritis weeks to months later, thereby linking the two events.

We did not expect that some patients would also develop other abnormalities. Over the next several years, as more patients with the skin lesion were seen in our clinic, we began to recognize that we were dealing with a complex illness, which often occurred in stages with different manifestations at each stage. We began to call it Lyme disease.

Methodically, we pieced together what we knew. The illness usually began in the late spring or early summer with a slowly expanding red skin lesion, often accompanied by flu-like symptoms, such as headache, neck stiffness, joint pain, or fever. Within weeks, the disease changed, with about 15 percent of patients developing a neurologic illness, such as meningitis, paralysis of facial nerves, or severe pain radiating from the spine to the arms, torso, or legs. Less commonly, during this period, about 5 percent of patients had abnormalities in the conduction system of the heart, sometimes resulting in a dangerously low heart rate. Then, the disease changed again. Months later, about 60 percent of patients developed intermittent or persistent attacks of arthritis affecting one or a few joints, especially the knee, often lasting or recurring over several years. The illness, however, was highly variable; most patients did not express all stages of the disease or sometimes the stages merged.


The recognition that an initial skin lesion was a part of this illness led us to home in on its likely cause. Within the study’s first year, a Danish dermatology resident alerted us that a similar slowly expanding skin lesion, called erythema migrans, had been known in Europe for years. This lesion was associated with the bite of Ixodes ricinus ticks (the sheep tick) and usually appeared to respond to penicillin therapy. However, subsequent arthritis, as we had observed, had not been noted in Europe, initially making it unclear whether we were dealing with the same illness.

Related: Is ‘chronic Lyme disease’ real?

We sifted through other clues as well. Residents of Lyme said that in the 1960s, they never saw ticks, but by the 1970s, they were inundated. Then, an ecologist doing field studies saved the tick that bit him where an erythema migrans formed. This tiny tick was identified as the immature stage of the deer tick, called Ixodes scapularis, similar to Europe’s sheep tick. Finally, as we saw or heard about more cases, we plotted their location on a map, which included sites in the Northeast, upper-Midwest, and Northern California. In 1979, we reported that the geographic distribution of cases correlated with the known locations of Ixodes scapularis ticks or the related Ixodes pacificus ticks. It seemed very likely that Lyme disease was a tick-transmitted infection, yet the causative agent carried by this tick remained elusive.


Dr. Allen Steere, of Massachusetts General Hospital, examined a Lyme-disease patient. Wendy Maeda/Globe staff/file 2013/Globe Staff

Because of the European experience, we began studies of penicillin therapy for erythema migrans, the initial skin lesion. Although some patients still had symptoms after treatment, patients who received the antibiotic did better than those who did not, results that we published in 1980. Moreover, we reasoned that an infection which occurred in stages that can be treated with penicillin — at least early in the infection — was suggestive of an infection caused by a spiral-shaped bacterium called a spirochete, such as the agent of syphilis. Thus, in 1980, we began a double-blind study in patients with Lyme arthritis, a late manifestation of Lyme disease, testing the penicillin regimen used to treat late syphilis. Only 35 percent of the penicillin-treated patients responded, but this was significantly better than the placebo-treated patients.

Building upon this knowledge, Willy Burgdorfer, an entomologist, and Dr. Alan Barbour, a postdoctoral fellow in infectious diseases, at the Rocky Mountain Laboratory, a branch of the National Institutes of Health, had the expertise necessary to identify the infectious agent. Burgdorfer had studied ticks throughout his long career and was expert at dissecting them and describing their infectious agents. Barbour had spent the year learning the complex requirements for growing Borrelia, a type of spirochete transmitted by ticks or lice. In 1982, while dissecting the mid-gut of a tiny nymphal Ixodes scapularis tick, Burgdorfer noted what looked like spirochetes. He gave the sample to Barbour, who, over the course of the next month, was able to grow a previously unrecognized spirochete — now called Borrelia burgdorferi. It was then possible to isolate the spirochete from patients with Lyme disease and show that these patients had an antibody response to the organism, proving the spirochetal cause of the infection.


Related: ‘The forest is not safe’: How Lyme disease struck fear into the heart of this nature lover

Since that discovery, knowledge about Lyme disease and its complexity and challenges has increased exponentially. The infection is now known to occur worldwide, primarily in the northern temperate zones. Within the United States, the tick that transmits the disease has spread rapidly. For example, the northeastern focus of the infection has moved northward into Canada, southward into Virginia, and westward through Pennsylvania. The Centers for Disease Control and Prevention estimates that 300,000 new cases of Lyme disease occur each year in this country. Furthermore, the strains that cause the infection in the Northeast are especially virulent and arthritogenic, and several long-lasting post-infectious syndromes have been identified. In addition, the deer tick is now known to transmit five other recently identified infectious agents. Clearly, Lyme disease and other tick-borne infections take an enormous toll on the public health of any affected community.


Related: Know your ticks and how to avoid them

Can something be done to halt this seemingly inexorable increase in tick-borne diseases? In a recent issue of The New England Journal of Medicine, Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, called for an intensive effort to develop vaccines for each of the agents transmitted by the deer tick. Additionally, a vaccine against tick salivary proteins might prevent successful tick feeding, thereby preventing all of these tick-borne infections. In fact, there is already a safe and effective vaccine for Lyme disease, but it is not available — the manufacturer withdrew it from the market in 2002 because antivaccine forces threatened large class-action lawsuits.

Watch: It’s time to take Lyme seriously

It’s time to take Lyme seriously
Mark Gartsbeyn / Globe Correspondent

Our nation may be reaching a tipping point in which the need and demand for a Lyme disease vaccine is widely recognized and supported. Mass vaccination would not be necessary, as with infections like measles that are spread from person-to-person. With Lyme disease, a person acquires the infection from a tick, not another person. Vaccinating for Lyme, therefore, would be a choice — an option for worried parents who want their children to be able to play safely outside, and protection for anyone who spends time in woody or grassy areas in endemic areas. As Lyme disease continues to escalate at an alarming rate, it is time to revisit and reassess the merits of vaccination as a logical way to address what has become a public health crisis.

Dr. Allen Steere is Professor of Medicine at Harvard Medical School and Massachusetts General Hospital. From 1994-1996, he was principal investigator of the phase III trial of the Lyme disease vaccine manufactured by Smith Kline Beecham. He is not a consultant for current vaccine manufacturers, and receives no money from such sources.