Lyme disease is a bacterial illness caused by Borrelia burgdorferi and spread to humans through the bite of infected ticks. While Tennessee has historically been considered a low-incidence state compared to the Northeast and Upper Midwest, this perception is rapidly changing. Understanding the true prevalence requires looking closely at official reports, the specific tick species active in the state, and the geographical factors influencing risk.
The Official Status of Lyme Disease in Tennessee
Tennessee is not categorized by the Centers for Disease Control and Prevention (CDC) as a high-incidence state for Lyme disease. The official reported numbers remain relatively low, but they show a clear trend of increasing year over year. In 2023, the Tennessee Department of Health reported 39 confirmed and probable cases, an 18% increase from the previous year.
The small number of official cases is partly due to the strict national surveillance case definition, which requires a specific combination of clinical evidence, laboratory results, and documented exposure. This reporting mechanism often leads to significant undercounting of the actual number of people treated for the illness. Studies suggest the true incidence could be many times higher than official reports, with some estimates proposing up to 7.5 times the reported number annually.
From 2013 to 2023, a total of 382 cases were documented across the state. The rise in reported cases reflects a genuine expansion of the tick vector population into the southeastern United States. The disease is reportable to public health authorities, which helps track the geographic spread and increasing risk over time.
Identifying the Primary Tick Vectors and Risk Zones
Lyme disease is transmitted exclusively by the Blacklegged Tick, Ixodes scapularis, also known as the deer tick. The presence of this specific tick species is the determining biological factor for Lyme risk in Tennessee. Other ticks abundant in the state, such as the Lone Star Tick and the American Dog Tick, do not transmit the Borrelia burgdorferi bacteria.
The Blacklegged Tick has been steadily expanding its territory, making Lyme disease a growing concern, particularly in the northern and eastern sections of the state. Counties in the Middle and Eastern Grand Divisions account for the vast majority of cases, with the highest incidence rates found along the northeast border with Virginia and North Carolina. This geographical pattern is due to the tick’s habitat preference for wooded and brushy areas prevalent in the Appalachian foothills and the Cumberland Plateau.
A significant difference from high-incidence states is the proportion of Blacklegged Ticks that carry the Lyme bacteria. In Tennessee, the prevalence of Borrelia in the local tick population is lower and more patchy, estimated at around 10% in some areas. Residents should take precautions when spending time outdoors in wooded areas, especially during the peak season from late spring through mid-summer.
Preventing a bite involves practical measures, such as using insect repellent containing DEET and wearing light-colored clothing to spot ticks easily. After being outside, a full-body tick check is important, and any attached ticks should be promptly removed. Ticks must typically be attached for 36 to 48 hours to successfully transmit the bacteria, making quick removal a highly effective prevention strategy.
Recognizing Symptoms and Steps for Seeking Care
If a person suspects a tick bite or has been active in a known risk zone, recognizing the early signs of infection is key to successful treatment. Symptoms usually begin 3 to 30 days after the bite. The most recognizable early sign is the erythema migrans rash, often described as a circular or “bullseye” pattern, which may feel warm but is typically not itchy or painful.
Approximately one-third of people infected with Lyme disease will not develop the characteristic rash. Early infection can also present with non-specific, flu-like symptoms, including fever, headache, chills, swollen lymph nodes, and muscle and joint aches. These symptoms alone can make diagnosis challenging, requiring a healthcare provider to consider a patient’s potential for tick exposure.
If not treated in the early stages, the infection can progress to involve the heart, joints, and nervous system, leading to severe conditions like facial paralysis or arthritis. The standard medical approach for early Lyme disease is a two- to four-week course of oral antibiotics. Timely treatment is directly linked to a greater chance of a full recovery, making immediate contact with a healthcare provider essential following a suspected bite or the onset of symptoms.