TICK-RACCOON ASSOCIATIONS AND THE POTENTIAL FOR LYME-DISEASE SPIROCHETE TRANSMISSION IN THE COASTAL-PLAIN OF NORTH-CAROLINA

Raccoons (Procyon lotor) were live-trapped and examined for ticks from July 1990 to July 1993 in the coastal plain of North Carolina on Mari ne Corps Base, Camp Lejeune, North Carolina (USA). Five species of ixo did ticks were found on 351 (78%) of 449 raccoons. Amblyomma americanu m was the most abundant tick found on raccoons. Dermacentor variabilis , Ixodes texanus, and Ixodes scapularis were frequently collected, whi le Ixodes cookei were rarely collected from raccoons. Tick burdens wer e not affected by the age, sex, or trap location of captured raccoons. Ticks parasitizing raccoons had varying seasonal patterns of abundanc e. Amblyomma americanum were generally collected from raccoons year ar ound, but infestation intensities were greatest in summer from June to September. Dermacentor variabilis adults were most abundant in mid-su mmer while peak numbers of larvae were collected in the fall. Infestat ion intensities of Ixodes texanus larvae were greatest in fall and win ter months while nymphs were most abundant in winter and spring. No ma les were collected from raccoons, but females were most frequently col lected in the spring and declined in abundance in the summer with no s pecimens collected in the fall or winter. Numbers of I. scapularis adu lts appeared to reach peak numbers in the fall while larvae and nymphs were most abundant on raccoons in winter. Spirochetes, Borrelia burgd orferi, were identified in a small percentage (0.2%) of host-seeking A . americanum nymphs and adults, and I. scapularis adults by immunofluo rescent antibody assays. Similarly, a small percentage (1.9%) of host- associated A. americanum, D. variabilis, I. texanus and I. cookei cont ained B, burgdorferi. Borrelia burgdorferi spirochetes were cultured f rom the blood of 23 (26%) of 87 raccoons.