EVIDENCE SUPPORTING THE PRESENCE OF BORRELIA-BURGDORFERI IN MISSOURI

Although Lyme disease is commonly seen in the southcentral United Stat es, the epidemiology of the disease is poorly defined there. The purpo se of this study was to document the presence of Borrelia burgdorferi in ticks collected in southeastern Missouri and around the city of St. Louis. Spirochetes were detected and identified as B. burgdorferi by immunofluorescent antibody (IFA) tests using the monoclonal antibody H 5332 in 1.9% of Amblyomma americanum and 2.0% of Dermacentor variabili s ticks collected. The identity of IFA-positive organisms was verified by polymerase chain reactions (PCRs) with two different sets of B. bu rgdorferi-specific primers followed by Southern blotting. The DNA sequ ences of amplified 371-basepair PCR products from two positive Missour i ticks showed 97-98% identity with that obtained by the same method f or the B31 strain of B. burgdorferi. These results confirm that B. bur gdorferi is present in questing D. variabilis and A. americanum ticks in areas of Missouri where Lyme disease occurs. Additional studies are needed to determine the role of these ticks in the epidemiology of Ly me disease in Missouri and neighboring states.