SEROLOGIC SURVEY FOR ANTIBODIES TO BORRELIA-BURGDORFERI IN WHITE-TAILED DEER IN ONTARIO

Serum samples collected from 623 white-tailed deer (Odocoileus virgini anus) in southern Ontario (Canada) from 1985 to 1989 were tested for a ntibodies to Borrelia burgdorferi using an indirect fluorescent antibo dy (IFA) staining method. Samples from 150 of the deer were also teste d using an enzyme-linked immunosorbent assay (ELISA). At IFA titers of 1:64 and 1:128 deer with antibodies to B. burgdorferi appeared to be widespread throughout southern Ontario, with an apparent prevalence ra nging from 3 to 47%. At IFA titres greater than or equal to 1:256 and ELISA titres greater than or equal to 1:160 deer with antibodies to B. burgdorferi were only present on Long Point which is the only known e ndemic focus of Ixodes scapularis, the primary vector for B. burgdorfe ri, in southern Ontario. At these titres he apparent prevalence of ant ibodies to B. burgdorferi on Long Point was only 5 to 7%, even though the mean intensity of infestation of adult I. scapularis on deer was > 180, and 60% of the adult ticks are infected with B. burgdorferi. Base d on these results, white-tailed deer do not appear to be a good senti nel species for the distribution of B. burgdorferi.