Lyme disease is a bacterial infection caused by Borrelia burgdorferi, transmitted to humans through the bite of infected ticks. However, Lyme disease is generally not considered common or endemic in Texas. The low risk of local transmission is rooted in the state’s unique ecology and the distribution of tick species.
Official Reporting and Local Transmission in Texas
Texas is officially categorized as a low-incidence state for Lyme disease. Surveillance data from the Texas Department of State Health Services (DSHS) shows an average of about 85 reported human cases per year between 2000 and 2020, a number small compared to high-incidence states.
The vast majority of reported cases in Texas are considered imported, meaning the person was infected while traveling to an endemic area and diagnosed after returning home. Cases contracted within the state are exceedingly rare, supporting the non-endemic status.
The bacterium Borrelia burgdorferi is transmitted by the blacklegged tick, Ixodes scapularis, which is present in limited counties, primarily in eastern Texas. Despite the presence of this vector, the local transmission rate remains very low, suggesting a complex ecological dynamic prevents a widespread disease cycle.
The Specific Ticks That Live in Texas
The dominance of a different tick species explains the low incidence of Lyme disease. The Lone Star Tick, Amblyomma americanum, is the most prevalent species across the state, particularly in wooded and brushy areas, and is recognizable by a distinct white or silver spot on the adult female.
The Lone Star Tick is not a competent vector for the Borrelia burgdorferi bacteria, keeping the risk of contracting Lyme disease locally low.
The blacklegged tick, Ixodes scapularis, the vector for Lyme disease, is present but far less common than the Lone Star Tick in most of Texas. It is typically found in higher concentrations in the eastern counties. Other common species, such as the American Dog Tick (Dermacentor variabilis) and the Gulf Coast Tick (Amblyomma maculatum), also populate the state and transmit other pathogens.
Recognizing Other Tick-Borne Illnesses
Residents and visitors in Texas should focus attention on diseases transmitted by prevalent local tick species. Southern Tick-Associated Rash Illness (STARI) is associated with the Lone Star Tick and often causes a rash resembling the bull’s-eye rash of Lyme disease, leading to frequent misdiagnosis.
The STARI rash is typically smaller than a true Lyme rash, and the illness does not progress to severe neurological or arthritic complications. Another significant risk is Ehrlichiosis, also transmitted by the Lone Star Tick, which presents as an acute febrile illness with symptoms like high fever, headache, and muscle aches.
Rocky Mountain Spotted Fever (RMSF) is a serious illness transmitted by the American Dog Tick and other species. RMSF is characterized by a high fever, intense headache, and a maculopapular rash that often starts on the wrists and ankles before spreading. This infection can progress rapidly and requires prompt treatment with antibiotics.
Effective Tick Prevention Strategies
Outdoor enthusiasts in Texas should adopt specific measures to reduce the risk of tick bites, especially during the extended warm season.
- Applying insect repellent containing DEET, picaridin, or oil of lemon eucalyptus to exposed skin provides a layer of protection.
- Treating clothing and gear with permethrin, a synthetic insecticide, can repel and kill ticks on contact.
- Wearing light-colored clothing makes it easier to spot ticks, and tucking pants into socks creates a physical barrier.
- After spending time in wooded or grassy areas, perform a thorough tick check, focusing on warm, moist areas like the groin, armpits, and scalp.
Yard maintenance can significantly reduce tick habitat around the home. Regularly mowing the lawn and promptly removing leaf litter and yard debris eliminates hiding spots. Creating a barrier of wood chips or gravel, at least three feet wide, between wooded areas and recreational spaces discourages ticks from migrating into the yard. Placing clothes in a dryer on high heat after an outdoor activity will also kill any clinging ticks.