Clark, Kerry

Kerry Clark, PhD, MPH
Professor of Epidemiology & Environmental Health
University of N. Florida, Jacksonville, FL

“Update on Evidence of Lyme Borrelia in Ticks, Dogs, and People in the Southeastern US”

Dr. Clark grew up in Louisville, KY, and obtained a bachelor’s degree in public health from Western Kentucky University. He then earned a Masters in Public Health Epidemiology from the University of Alabama at Birmingham, and a Ph.D. in Environmental Health Sciences from the University of South Carolina. His doctoral research included the first ecologic study of Lyme Borrelia spirochetes in that state. For the past 20 years, he has been studying Lyme and other tick-borne diseases in the southern United States. In addition to his research, he teaches graduate and undergraduate courses in epidemiology and environmental health in the Department of Public Health at UNF.

Lyme Disease Research
Dr. Clark’s research is focused on the ecology and epidemiology of Lyme disease and other tick-borne diseases in the southern U.S. He was the first to report finding Lyme disease spirochetes in animals and ticks in South Carolina, and in wild lizards in South Carolina and Florida. He has documented the presence of Lyme disease Borrelia species, Babesia microti, Anaplasma phagocytophilum, Rickettsia species, and other tick-borne pathogens in wild animals, ticks, dogs, and humans in Florida and several other southern states.

The primary objectives of Dr. Clark’s research are:
1. To develop better molecular/DNA based tests for identifying the causative agents of Lyme and associated tick-borne diseases to improve sensitivity and specificity of detection in both human patients and companion animals;
2. To use improved testing methods to determine the actual frequency of Lyme disease and common coinfections in humans and companion animals, the prevalence of infection in ticks, and the true tick vector species of these diseases to humans and our pets; and
3. To improve awareness and early recognition of tick-borne diseases through dissemination of the research findings and comprehensive education efforts.

Conference Lecture Summary

Lyme disease continues to be a controversial subject in the southern United States. Based solely on 2-tiered serological laboratory confirmation test results, the disease continues to appear to be relatively rare in this region compared to highly endemic areas of the Northeast and Upper Midwest. However, some more recently obtained evidence challenges this belief. Borrelia burgdorferi sensu lato (Bbsl) DNA has been detected in scores of human patients and dogs from southern states, many of which have no travel history to other regions. Bbsl has also been isolated in culture from several human patients from Florida and Georgia, most of which have not been described in the scientific literature. DNA evidence of Bbsl continues to be detected in lone star ticks (Amblyomma americanum), which may serve as a bridge vector of transmission to humans under certain circumstances. This report summarizes some of the published and unpublished evidence of Lyme Borrelia infection in humans, dogs, and ticks from several southern states, attempts to help explain the disparity between surveillance case numbers and observed Lyme-like illness in the southern U.S., and provides insights into better understanding the ecology and epidemiology of Lyme disease in the South.