Lyme disease, caused by the bacteria Borrelia burgdorferi, the infection can cause disease in humans and dogs. Lyme disease continues to be the most commonly reported vector-borne disease of humans in the United States. Since 1975, when the disease was first recognized in a cluster of arthritic children in Lyme, Connecticut, disease clusters have emerged and expanded in several parts of the U.S.

In the north-central U.S., expansion in the distribution of the disease and its vector, the deer tick or blacklegged tick (Ixodes scapularis), has been occurring since the bacterium was first detected in Wisconsin during the mid-1980s. The tick was first detected in northwestern Illinois in 1987. By 1989, the tick was established in the northwestern part of the state and B. burgdorferi was isolated from ticks collected in Castle Rock State Park. Since then, additional tick clusters have been detected along the Rock and Mississippi rivers and more recently, along the northern and central portions of the Illinois River. In extensively farmed Illinois, suitable forested habitats that are necessary for the ticks occur primarily along riparian corridors.

Successful establishment of B. burgdorferi into a new site depends on three requirements: 1) the presence of the deer tick; 2) availability and suitability of tick hosts; and 3) competent reservoir hosts for the bacteria. Our group has developed a risk map for I. scapularis establishment based on environmental factors that are associated with tick survival. Our long-term goal is to characterize the significant determinants for Lyme disease establishment in the Midwest and the eastern U.S. in order to facilitate surveillance and control strategies.

Figure 1: a burned area at Castle Rock State Park during collection of ticks in August 2001.

Financial support: This research is supported through a cooperative agreement with the Center for Disease Control and Prevention (CDC).

Participants:
Uriel Kitron
Roberto Cortinas
Evelin Grijalva
Christina North
Tony Cappa
Dave Swedler
Jennifer Smith
Cathy Panozzo

Recent Papers:
Stafford, K. III and U. Kitron. 2002. Environmental Management for Lyme Borreliosis Control In: Gray J, Kahl O, Lane R & Stanek G (Eds) Lyme Borreliosis: Biology, Epidemiology and Control, pp. 301-334. CAB International.

Cortinas MR, Guerra MA, Jones CJ, Kitron U. Detection, Characterization, and Prediction of Tick-borne Disease Foci. 2002. International Journal of Medical Microbiology 291, Suppl. 33: 11-20.

Guerra M.A. et al. 2002. Predicting the Risk of Lyme Disease: Habitat Suitability for Ixodes scapularis in the North Central United States.
Emerging Infectious Diseases, 8, 3, 289-297

Guerra MA., Walker ED, Kitron U. 2001. Canine surveillance systems for Lyme borreliosis in Wisconsin and northern Illinois: geographic distribution and risk factor analysis. Am. J. Trop. Med. Hygiene 65: 546-552.

Guerra MA, Walker ED, U Kitron. 2000. Quantitative approach for the serodiagnosis of canine Lyme disease by the immunoblot procedure. Journal of Clinical Microbiology 38: 2628-2632.

Jones CJ & UD Kitron. 2000. Populations of Ixodes scapularis (Acari: Ixodidae) are modulated by drought at a Lyme disease focus in Illinois. Journal of Medical Entomology 37: 408-415.