Southern Tick-Associated Rash Illness

Introduction: A rash similar to the rash of Lyme disease has been described in humans residing in southeastern and south-central states and is associated with the bite of the lone star tick, Amblyomma americanum. This Lyme disease-like rash has been named Southern tick-associated rash illness (STARI).

Image: Adult female Amblyomma americanum tick. Note the characteristic “lone star.” (View enlarged image.)

Vector: Amblyomma americanum ticks are found through the southeast and south-central states. Their life cycle and ecologic requirements are similar to Ixodes ticks with minor exceptions not described here. All three life stages of A. americanum aggressively bite people in the southern U.S. Research indicates that live spirochetes are observed in only 1-3% of A. americanum.

The Bacterium: Even though spirochetes have been seen in A. americanum ticks by microscopy, attempts to culture it in the laboratory have consistently failed. Modified BSK (Barbour-Stoenner-Kelly) is the best medium for cultivating the Lyme disease spirochete, B. burgdorferi, but is apparently not suitable for cultivating the spirochete found in A. americanum. However, a spirochete has been detected in A. americanum by DNA analysis and was given the name Borrelia lonestari.

Image: Patient with a classic erythema migrans; 1) site of tick bite, 2) red, radial, expanding edge of rash. 3) central clearing.   Photograph used with permission from the Journal of Infectious Diseases.

Symptoms and Diagnosis: Persons living or traveling in southeast or southcentral states who develop a red, expanding rash with central clearing (the rash of Lyme disease, erythema migrans) following the bite of the lone star tick, A. americanum, should see their physician. The Centers for Disease Control and Prevention is interested in obtaining samples from such patients under an Institutional Review Board-approved investigational protocol.

Epidemiology and Risk: In 2001, a patient with evidence of B. lonestari infection was reported in the medial literature. This patient had exposure to ticks in Maryland and North Carolina and developed a rash indistinguishable from erythema migrans after an A. americanum tick bite. DNA analysis indicated the presence of B. lonestari in a skin biopsy taken at the leading edge of the rash and in the tick removed by the physician. Serologic testing for Lyme disease was negative. The patient was treated with an oral antibiotic and returned to normal health.

Image: Map showing distribution of lone star ticks in the United States.   Redrawn and updated from Hair and Bowman, 1986.

Lone star ticks can be found from central Texas and Oklahoma eastward across the southern states and along the Atlantic coast as far north as Maine. Although several studies have demonstrated that 1-3% of these ticks are infected with a spirochete, a thorough assessment of risk of infection has not been conducted.

Prevention and Treatment: Prevention measures similar to those for the Lyme disease vector will reduce your exposure to infected ticks. See Lyme Disease Prevention and Control for information on how to

• avoid tick habitats,
• reduce tick abundance,
• use personal protection equipment, and
• check and remove ticks.

In most circumstances, treating persons who only have a tick bite is not recommended. Individuals who are bitten by any tick should remove the tick and seek medical attention if any signs and symptoms of early Lyme disease, Lyme disease-like illness (STARI), ehrlichiosis, babesiosis, or tularemia develop over the ensuing days or weeks.

References:

Barbour AG, Maupin GO, Teltow GJ, Carter CJ, Piesman J. Identification of an uncultivable Borrelia species in the hard tick Amblyomma americanum: possible agent of a Lyme disease-like illness. Journal of Infectious Diseases 1996 Feb;173(2):403-409.

Burkot TR, Mullen GR, Anderson R, Schneider BS, Happ CM, Zeidner NS. Borrelia lonestari DNA in adult Amblyomma americanum ticks, Alabama. Emerging Infectious Diseases 2001 May-Jun;7(3):471-473.

Campbell GL, Paul WS, Schriefer ME, Craven RB, Robbins KE, Dennis DT. Epidemiologic and diagnostic studies of patients with suspected early Lyme disease, Missouri, 1990-1993. Journal of Infectious Diseases 1995 Aug;172(2):470-480.

Felz MW, Chandler FW Jr, Oliver JH Jr, Rahn DW, Schriefer ME. Solitary erythema migrans in Georgia and South Carolina. Archives of Dermatology 1999 Nov;135(11):1317-1326.

Fukunaga M, Okada K, Nakao M, Konishi T, Sato Y. Phylogenetic analysis of Borrelia species based on flagellin gene sequences and its application for molecular typing of Lyme disease borreliae. Int J Syst Bacteriol. 1996 Oct;46(4):898-905. Journal of Medical Entomology 1992 May;29(3):525-530.

Georgia Department of Human Resources, Division of Public Health, Epidemiology Branch. Tick Bites and Erythema Migrans in Georgia: It Might NOT be Lyme Disease! (565 KB, 4 pages). Georgia Epidemiology Report 2001 Aug;17:1-3.

Hair JA, Bowman JL. Behavioral ecology of Amblyomma americanum (L.). In: Sauer RJ and Hair HA, eds. Morphology, physiology, and behavioral biology of ticks. West Sussec England: Ellis Worwood Limited, 1986:407.

James AM, Liveris D, Wormser GP, Schwartz I, Montecalvo MA, Johnson BJB. Borrelia lonestari infection after a bite by an Amblyomma americanum tick. Journal of Infectious Diseases 2001 Jun 15;183(12):1810-1814.

Kirkland KB, Klimko TB, Meriwether RA, Schriefer M, Levin M, Levine J, MacKenzie WR, Dennis DT. Erythema migrans-like rash illness at a camp in North Carolina: a new tick-borne disease? Archives of Internal Medicine 1997 Dec 8-22;157(22):2635-2641.

Luckhart S. Mullen GR, Durden LA, Wright JC. Borrelia species in ticks recoverd from white-tailed deer in Alabama. Journal of Wildlife Diseases 1992;28:449-452.

Masters E, Granter S, Duray P, Cordes P. Physician-diagnosed erythema migrans and erythema migrans-like rashes following Lone Star tick bites. Archives of Dermatology 1998 Aug;134(8):955-960.

Melski JW. Language, logic, and Lyme disease. Archives of Dermatology 1999 Nov;135(11):1398-1400.

Moody EK, Barker RW, White JL, Crutcher JM. Ticks and tick-borne diseases in Oklahoma. Journal of the Oklahoma State Medical Association 1998 Nov;91(8):438-445.

Oliver JH Jr, Kollars TM Jr, Chandler FW Jr, James AM, Masters EJ, Lane RS, Huey LO. First isolation and cultivation of Borrelia burgdorferi sensu lato from Missouri. Journal of Clinical Microbiology 1998 Jan;36(1):1-5.

Piesman J, Happ CM. Ability of the Lyme disease spirochete Borrelia burgdorferi to infect rodents and three species of human-biting ticks (blacklegged tick, American dog tick,lone star tick) Acari:Ixodidae). Journal of Medical Entomology 1997 Jul;34(4):451-456.

Piesman J, Sinsky RJ. Ability of Ixodes scapularis, Dermacentor variabilis, and Amblyomma americanum (Acari: Ixodidae) to acquire, maintain, and transmit Lyme disease spirochetes (Borrelia burgdorferi). Journal of Medical Entomology 1988 Sep;25(5):336-339.

Ras NM, Lascola B, Postic D, Cutler SJ, Rodhain F, Baranton G, Raoult D. Phylogenesis of relapsing fever Borrelia spp. International Journal of Systematic Bacteriology 1996 Oct;46(4):859-865.

Rich SM, Armstrong PM, Smith RD, Telford SR 3rd. Lone star tick-infecting borreliae are most closely related to the agent of bovine borreliosis. Journal of Clinical Microbiology 2001 Feb;39(2):494-497.

Ryder JW, Pinger RR, Glancy T. Inability of Ixodes cookei and Amblyomma americanum nymphs (Acari: Ixodidae) to transmit Borrelia burgdorferi. Journal of Medical Entomology 1992 May;29(3):525-530.

Stromdahl EY, Evans SR, O'Brien JJ, Gutierrez AG. Prevalence of infection in ticks submitted to the human tick test kit program of the U.S. Army Center for Health Promotion and Preventive Medicine. Journal of Medical Entomology 2001 Jan;38(1):67-74.

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