Notes on responses of blacklegged ticks (Acari: Ixodidae) to host urine.

In laboratory bioassays under conditions of high humidity, host-seeking female black-legged ticks, Ixodes scapularis Say, avoided urine of reproductively active male and nonestrous female white-tailed deer, Odocoileus virginianus (Zimmermann), the principal host species of the adult stage. At 50% RH, female I. scapularis did not avoid urine from male and female deer. Larval and nymphal I. scapularis did not exhibit an arrestment response to urine from male and female white-footed mice, Peromyscus leucopus (Rafinesque), a major host for immature blacklegged ticks. These results suggest that under some conditions, urine from 2 principal host species in certain physiological states does not provide kairomonal cues that aid I. scapularis in contacting these host species.

Detection of Borrelia burgdorferi in urine of Peromyscus leucopus by inhibition enzyme-linked immunosorbent assay.

An inhibition enzyme-linked immunosorbent assay was developed to detect Borrelia burgdorferi, the etiologic agent of Lyme borreliosis, in urine from white-footed mice (Peromyscus leucopus). Of the 87 urine specimens tested from 87 mice collected in widely separated tick-infested sites in Connecticut, 57 (65.5%) contained detectable concentrations of spirochetal antigens. Forty-seven (62.7%) of 75 serum samples analyzed contained antibodies to B. burgdorferi. In culture work with tissues from bladders, kidneys, spleens, or ears, 50 of 87 mice (57.5%) were infected with B. burgdorferi. Thirty-eight (76%) of 50 infected mice had antigens of this spirochete in urine, while 36 (72%) individuals had infected bladders. Of those with infected bladders, 24 (66.7%) mice excreted subunits or whole cells of B. burgdorferi into urine. Successful culturing of B. burgdorferi from mouse tissues, the presence of serum antibodies to this bacterium, and detection of antigens to this spirochete in urine provide further evidence that multiple assays can be performed to verify the presence of B. burgdorferi in P. leucopus.