The causative bacteria Borrelia burgdorferi
was not officially classified until 1981, when scientist Wilhelm Burgdorfer discovered that a spirochete carried by ticks was causing Lyme disease. Since then, the number of reports and geographic expansion of Lyme disease have increased dramatically in the United States, and the Centers for Disease Control and Prevention (CDC) included Lyme disease in their top 10 notifiable diseases in 2012.3
However, Patricia V. Smith, president of the Lyme Disease Association,
noted that the extent of Lyme disease in the United States may be underestimated in many states because they do not have the money to perform surveillance and identify the extent of the infected tick population.
Lyme disease has also been reported in about 80 countries worldwide, although Robert C. Bransfield, MD, DLFAPA,
said that it is unclear whether Lyme disease is endemic in those countries or whether it spread from the northeastern United States. “It seems like we’re more aware of it, and now that we’re more aware of it, we identify it,” he said. He pointed out that the increased rates of diagnosis may be due in part to greater awareness. “In years past, it was called many other things,” he said.
However, Dr. Bransfield noted that there is debate among experts about whether to use a narrow or broad definition for identifying and treating Lyme disease. The diagnostic criteria from the CDC are narrow, as their primary purpose is to monitor the national rate of Lyme disease with a high degree of specificity in the diagnosis. For example, the CDC criteria do not recognize Lyme disease in patients with late-onset encephalopathy and a positive blood test, and physicians who use the CDC criteria may fail to diagnose Lyme disease in some patients. By contrast, physicians who use more inclusive clinical criteria for probable cases of Lyme disease may initiate treatment in some patients who do not have the disease, with the rationale that long-term risks with Lyme disease outweigh the risks associated with antibiotic therapy.
Experts generally agree about the signs and symptoms in acute phases of Lyme disease, which may include fever, chills, headache, fatigue, muscle and joint aches, swollen lymph nodes, and an erythema migrans rash that begins at the site of the tick bite, 3 to 30 days after the bite and spreads gradually. However, the concept of chronic Lyme disease is controversial among experts, according to Dr. Shor, and no systematic evidence supports the presence of Borrelia burgdorferi
in patients with chronic symptoms after treated Lyme disease.