Public concern about ticks and the risk of Lyme disease often rises with warmer weather and increased outdoor activity. For residents and visitors to Missouri, understanding the specific local risk profile is important for safe outdoor recreation. This article clarifies the connection between ticks in Missouri and Lyme disease, while highlighting other more prevalent local tick-borne illnesses.
The Blacklegged Tick: The Lyme Disease Vector
The agent responsible for transmitting Lyme disease is the bacterium Borrelia burgdorferi. This bacteria is spread exclusively through the bite of the Blacklegged Tick (Ixodes scapularis), often referred to as the Deer Tick. This tick undergoes a two-year life cycle with four distinct stages, requiring a blood meal to progress from one stage to the next.
Transmission most commonly occurs during the nymph stage, which is about the size of a poppy seed and difficult to detect. The adult tick is slightly larger and also poses a risk. For transmission of the Lyme bacteria to occur, the infected tick needs to be attached and feeding for more than 24 hours. Prompt removal of an attached tick is an effective way to prevent infection.
Local Transmission Status of Lyme Disease in Missouri
The Blacklegged Tick is established in Missouri and found throughout the state, meaning the potential for local Lyme disease transmission exists. Despite this, Missouri is not classified as a high-incidence state for Lyme disease, unlike regions in the Northeast and Upper Midwest. The state’s incidence of locally acquired cases is significantly lower than that of other tick-borne illnesses.
Missouri health officials report cases meeting the CDC’s surveillance definition for Lyme disease. Historically, many local instances have been referred to as “Lyme-like disease” or Southern Tick-Associated Rash Illness (STARI). This is because while patients present with a similar illness, including the characteristic “bulls-eye” rash (erythema migrans), the Borrelia burgdorferi bacteria has not been isolated from all cases originating within the state. Although local transmission is possible, the overall risk in Missouri is considered lower than in high-incidence regions.
Other Tick-Borne Illnesses Prevalent in Missouri
While Lyme disease garners significant public attention, Missouri residents face a more immediate threat from other tick-borne pathogens. The state is considered a hotspot for several other tick-related diseases. Ehrlichiosis is a common illness transmitted primarily by the Lone Star Tick (Amblyomma americanum).
Rocky Mountain Spotted Fever (RMSF) is also a concern, as Missouri ranks among the top states for reported cases. RMSF is carried by the American Dog Tick (Dermacentor variabilis). The Lone Star Tick is also responsible for transmitting the agent that causes Alpha-Gal Syndrome, an allergy to red meat. This reaction is triggered by a sugar molecule called alpha-gal that the tick introduces during feeding.
Other serious, though less common, diseases present in the state include Tularemia, carried by the Lone Star and American Dog Ticks, and two viral infections, Heartland virus and Bourbon virus. The prevalence of these diseases means the overall risk from a tick bite in Missouri is substantial, even if the risk of Lyme disease is comparatively lower. Symptoms for many of these illnesses often begin with fever, headache, and fatigue, making early diagnosis challenging.
Preventing Tick Bites and Safe Removal Techniques
Effective prevention relies on vigilance and protective measures when spending time outdoors, especially in wooded or grassy areas. Wearing light-colored clothing makes it easier to spot ticks before they attach, and tucking long pants into socks creates a barrier. Treating clothing and gear with products containing 0.5% permethrin provides long-lasting protection. Applying EPA-approved repellents containing DEET to exposed skin is also recommended.
After returning indoors, a thorough full-body check for ticks is advisable. Any clothing worn outdoors should be placed in a dryer on high heat for at least ten minutes to kill remaining ticks. If a tick is found attached, it should be removed as quickly as possible to minimize the risk of disease transmission.
To safely remove an attached tick, use fine-tipped tweezers to grasp the tick as close to the skin’s surface as possible, near the mouthparts. Pull upward with steady, even pressure, avoiding twisting or jerking motions. Once the tick is removed, the bite area and hands should be cleaned thoroughly with rubbing alcohol or soap and water.