Lyme disease gets its name from the town in Connecticut where symptoms of the disease were documented and studied in the 1970s. However, this is only one small part of the story of Lyme disease in the U.S. and beyond. In this article, learn about the history of Lyme disease, from pre-historic times to today’s increase in cases due to climate change and other factors.

A brief history of Lyme disease

Lyme and ancient history

In 2017, a team at the Yale School of Public Health studied the history of Lyme disease in North America by analyzing the DNA of the Lyme disease bacterium – a group of species of spiral-shaped bacteria, or spirochetes, known as Borrelia. (There are several species and strains of Borrelia that can cause Lyme, which will be explored later in this article.)

The Yale researchers sequenced the full genomes of Borrelia burgdorferi sensu stricto taken from deer ticks. They read all one million letters of this full Lyme bacterial genome, allowing them to trace its presence back at least 60,000 years. That means the Lyme bacterium has been circulating North America since long before humans even arrived on the continent.

The researchers concluded that the bacterium most likely spread from the northeast U.S. to the south and west to California. This confirms that in the U.S. today, Lyme disease is not limited to New England but is in fact present in all 50 states.

Pre-20^th century: Lyme in colonial America
In North America, the history of Lyme disease and humans dates back at least to the colonial period. Colonists and visitors to North America in the 17^th and 18^th centuries wrote about the prevalence of ticks in forested areas of the Northeast as well as people suffering Lyme-like symptoms.

In fact, these accounts coupled with the Yale research above suggest that Lyme did not emerge through evolutionary processes, but rather changed and spread geographically due to ecological changes starting around that time.

Researchers cite the relationship between deforestation and intensive hunting during the colonial period followed by an “explosion” in the white-tailed deer population as a possible cause of the increase in tick populations and thus Lyme disease in the last century.

Early 1900s: Erythema migrans rash described in Europe
Between 1909 and 1912, Swedish dermatologist Arvid Afzelius presented research on what is now known as the bull’s eye shaped erythema migrans (EM) rash. At this time, he speculated that the rash was associated with bites from Ixodes ticks. This observation led to research confirming the moderate success of penicillin in treating EM throughout the first half of the 20^th century, an early step in recognizing the role of antibiotics in Lyme disease treatment.

One of the three main species of Lyme-causing Borrelia, Borrelia afzelii, is named after Afzelius.

1976: Lyme symptoms documented around Lyme, Connecticut
Beginning in the fall of 1975, families around Old Lyme, Lyme, and East Haddam, Connecticut, were suddenly stricken with mysterious cases of arthritis and juvenile arthritis.

Along with these arthritic symptoms, the adults and children in these families had a host of other seemingly inexplicable symptoms, including (in 25% of the patients) the erythema migrans rash.

Unable to obtain diagnoses that could explain these strange symptoms, the families sought the help of the Connecticut State Department of Health and the Yale School of Medicine. This began the investigation that culminated in the documentation and naming of Lyme disease in 1976.

This 1976 study not only characterized Lyme disease as such, but also suggested ticks as the disease vector.

1980: Research with antibiotics suggests bacterial cause of Lyme
Though what we now know as Lyme disease was first characterized in the 1976 study mentioned above, the bacterial cause of the disease wasn’t fully understood until the 1980s. That’s when the researchers from the 1976 study above, Allan C. Steere, MD, and Stephen E. Malawista, MD, determined that antibiotic treatment was effective in treating patients with the EM rash and other Lyme symptoms.

It would only be a matter of years before another scientist confirmed their hunch that Lyme disease was caused by a bacterial infection spread by the bite of an arthropod such as a tick. Keep reading to learn more.

1982: Borrelia burgdorferi discovered
While studying Rocky Mountain Spotted Fever – a deadly tick-borne disease also endemic in the U.S. – in 1981, scientist William Burgdorfer began studying Lyme disease. In 1982, Burgdorfer and his team isolated the infectious agent that causes Lyme. His research helped the medical community confirm not only the bacterial cause of Lyme disease but also the connection between the bacterium and deer ticks.

This bacterium was later named Borrelia burgdorferi in Burgdorfer’s honor.

Lyme disease today
The history of Lyme disease is far from over. Research continues to uncover not only new species of disease-causing Borrelia, but also developments in the changing geography of disease as well as better diagnostics and treatment.

Other species of Borrelia discovered

Species of Borrelia that are known to cause Lyme disease are collectively called Borrelia burgdorferi sensu lato. However, this broad classification includes many species and strains of disease-causing bacteria, which vary geographically and by the types of ticks that carry them.

Until recently, scientists recognized only three main species of Lyme-causing Borrelia:

• afzelii – Named after the Swedish dermatologist who discovered the bull’s eye rash and its connection to tick bites, this is a species of Borrelia that causes Lyme disease in Europe and Asia
• garinii – Another species of Borrelia common in Eurasia
• burgderfori sensu stricto – As mentioned above, this species was discovered in 1982 and is predominant in North America, but is also present in Europe

However, to date, at least thirteen distinct genomic classifications of Lyme-causing Borrelia have been discovered worldwide, some of which are continent- or country-specific. In North America, for example, several cases of Lyme have been caused not by B. burgdorferi but by the separate species B. mayonii. This is not to mention the totally separate group of species of Borrelia that cause a distinct type of Borreliosis, known as Tick-Borne Relapsing Fever (TBRF), that present with “Lyme-like” symptoms.

These various species and strains of Borrelia have serious implications for diagnostic testing of both Lyme disease and TBRF, since tests can miss infections if they are not equipped to detect certain species or strains of the disease-causing bacteria.

Common Lyme and TBRF Borrelia Species*

*IGeneX cannot confirm the accuracy of the above information, but it illustrates the discovery of many borrelia species since 1994 that cause Lyme disease and TBRF, and the need for comprehensive testing.

Climate change increases the threat of Lyme disease

Lyme disease is the most common vector-borne disease in the U.S. according to the CDC. In fact, the CDC estimates that there are at least 300,000 cases of Lyme disease in the U.S. every year, acknowledging that cases have tripled since 1995.

Experts are increasingly recognizing climate change as a major cause for the increase in cases. Warmer winters allow ticks to survive farther north than usual, expanding the geography of the disease, and lengthier summers extend the peak period of disease.

The need for better diagnostics

Another potential reason that cases of Lyme disease are increasing is that diagnostic tests are getting better at detecting the disease. Yet there is still much work to be done in this arena. Too many Lyme patients are still misdiagnosed, leading to serious financial and health consequences. And there is still too little understanding of the causes, consequences, and best treatment of chronic Lyme disease. The scientific and medical communities should continue research into diagnosing and treating Lyme.

IGeneX is committed to contributing to this research by developing more sensitive and accurate Lyme disease tests. Learn more today about IGeneX’s testing for Borrelia.