| Abstrakt: |
ABSTRACTWe used a nested PCR with Borreliaflagellin gene (flaB) primers and DNA sequencing to determine if Borrelia lonestariwas present in Amblyomma americanumticks removed from military personnel and sent to the Tick-Borne Disease Laboratory of the U.S. Army Center for Health Promotion and Preventive Medicine. In our preliminary investigation, we detected Borreliasequences in 19 of 510 A. americanumadults and nymphs from Ft. A. P. Hill, Va. During the 2001 tick season, the flaBprimers were used to test all A. americanumsamples as they were received, and 29 of 2,358 A. americanumsamples tested individually or in small pools were positive. PCRs with 2,146 A. americanumsamples in 2002 yielded 26 more Borrelia-positive samples. The positive ticks in 2001 and 2002 were from Arkansas, Delaware, Kansas, Kentucky, Maryland, New Jersey, North Carolina, Tennessee, and Virginia. The last positive sample of the 2001 season was a pool of larvae. To further investigate larval infection, we collected and tested questing A. americanumlarvae from Aberdeen Proving Ground, Md.; 4 of 33 pools (40 larvae per pool) were positive. Infection of unfed larvae provides evidence of the maintenance of B. lonestariby means of transovarial transmission. Sequence analysis revealed that the amplicons were identical to sequences of the B. lonestari flaBgene in GenBank. Despite the low prevalence of infection, the risk of B. lonestaritransmission may be magnified because A. americanumis often abundant and aggressive, and many tick bite victims receive multiple bites. |
