A method and device for measuring force transfers between the deep flexors in the musician''s hand

The efficacy of passive immunisation against tick-transmitted Lyme disease spirochaetal infection was determined in relation to the duration of previous feeding of infected vector ticks. Thus, mice challenged with spirochaete-infected unfed or partially fed nymphal ticks were passively immunised with monoclonal and polyclonal antibodies against the Lyme disease spirochaete (Borrelia burgdorferi) at various intervals after tick attachment. Spirochaetal infection in challenged mice and engorged ticks was verified by xenodiagnosis and indirect immunofluorescent antibody assay, respectively. Although tick-transmitted spirochaetal infection could be aborted by anti-OspA antibodies and hyperimmune antiserum, nearly all immunised mice challenged with infected ticks that had previous 36-h attachment became infected. More than 72% of the nymphal ticks used in this challenge retained their B. burgdorferi infection after engorgement on mice immunised with anti-spirochaete antibodies, and their subsequent infectivity to mice remained effective. It is concluded that a higher efficiency of transmission by partially fed infected nymphs and a lower efficacy of passive immunisation against infection result from an effect of previous feeding of infected ticks that activates antigenic change and enables the spirochaetes to circumvent OspA-based humoral immunity.     

OspA antibodies inhibit the acquisition of Borrelia burgdorferi by Ixodes ticks

Ixodes ticks are infected by Borrelia burgdorferi when larvae feed on spirochete-infected mice. We studied the acquisition of B. burgdorferi by larval ticks, characterized the production of outer surface protein A (OspA) by spirochetes entering larvae, and examined the effects of OspA antibodies on the establishment of B. burgdorferi infections in ticks. Most larvae were infected by spirochetes 24 to 48 h after placement on mice. OspA antibodies stained the first spirochetes observed in larvae, suggesting that OspA is synthesized early during the colonization of the vector. When OspA antibodies were administered to B. burgdorferi-infected mice and larvae were then placed on the animals, the severity of larval infection and the number of infected ticks (7 of 16) were decreased compared with that of controls (15 of 16). The inhibitory effects of OspA antibodies were observed with passive antibody transfer as well as active host-generated immunity. The lower larval infection rate observed in the presence of OspA antibodies was exacerbated after the larval molt since only 1 of 12 nymphs was infected, and none of the mice that were fed upon by these nymphs became infected with B. burgdorferi. Therefore, an OspA antibody response in mice altered the reservoir competence of the vertebrate host by inhibiting the movement of B. burgdorferi from the host to the vector.     

Seasonal variation in the capacity of the bank vole to infect larval ticks (Acari: Ixodidae) with the Lyme disease spirochete, Borrelia burgdorferi

Seasonal variation in the capacity of bank voles, Clethrionomys glareolus (Schreber), to infect larval Ixodes ricinus (L.) ticks with Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner was examined from May through October 1991 at Bogesund, near Stockholm in south-central Sweden. Although larval infestations of bank voles were greatest in June and July, nearly 70% of all larval ticks infected with spirochetes by bank voles at this site became infected during August and September. Seasonality of infectivity was related to the degree of earlier nymphal infestation on voles as well as to the age composition of the vole population. These factors may influence the infectivity of other rodent reservoirs of B. burgdorferi, both in Europe and North America. Moreover, in determining the reservoir potential of tick hosts, a host population's spirochetal infectivity should be determined for the entire period of larval infestation rather than just during the period of peak larval infestation.     

Characterization of Borrelia burgdorferi isolated from different organs of Ixodes ricinus ticks collected in nature

Borrelia burgdorferi was isolated from 22 out of 133 adult Ixodes ricinus ticks collected from vegetation at two sites in Switzerland. From 17 ticks, spirochetes could be isolated from more than one organ. When the different isolates obtained from one tick were compared by SDS-PAGE analysis, differences in the protein profiles were observed in 8 cases. The isolates were further compared by immunological methods using mono- and polyclonal antibodies. Differences were observed in the proteins of 31-35 kDa and 18-25 kDa. Genetic divergence among isolates was evaluated by use of a B. burgdorferi specific gene probe for ospA. Correlation could be observed between immunological differences in OspA defined by monoclonal antibody LA31 and genetic variation of ospA as judged by restriction fragment length polymorphism (RFLP). Our findings indicate that systemic infection in unfed I. ricinus adults, as reflected by isolation of B. burgdorferi from multiple organs of one tick, is more frequent (8/22, 36%) than previously described (5%). Moreover, the presence of different B. burgdorferi phenotypes/genotypes in one tick is described for the first time. The findings may have bearings (i) on the time of tick attachment required for spirochete transmission since borreliae are already present in the salivary glands of systemically infected ticks at the beginning of the blood meal and (ii) perhaps also on the diversity of B. burgdorferi phenotypes inoculated by these ticks.     

Plasminogen is required for efficient dissemination of B. burgdorferi in ticks and for enhancement of spirochetemia in mice

The role of the host plasminogen activation system in transmission of and invasion by Borrelia burgdorferi, the tick-borne spirochetal agent of Lyme disease, was investigated using plasminogen (Plg)-knockout mice. PLG was not detected in spirochetes from unfed ticks, but binding occurred as ticks fed on the host's blood. Plasminogen activators were derived from the host blood meal. PLG was required for efficient dissemination of B. burgdorferi within the tick and for enhancement of spirochetemia in mice but was not critical for transmission and infection. These results provide evidence for a bacterium using a vertebrate protease to disseminate in an invertebrate vector and underscores the interplay among vector, pathogen, and host in promoting the life cycle and disease.     

Comparison of polymerase chain reaction with culture and enzyme immunoassay for diagnosis of pertussis

The risk for human infection with Lyme disease appears linked to the abundance of infected vector ticks, principally Ixodes dammini Spielman, Clifford, Piesman & Corwin, in the eastern United States. Habitat destruction by burning, although not well studied, has long been considered as an effective alternative to synthetic insecticides as a means of reducing tick populations. We evaluated the effect of a single spring burning of the woodland understory on the transmission risk of Lyme disease spirochetes (Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner) on Shelter Island, Long Island, NY. Following a burn in early April 1991, the abundance of nymphal I. dammini was 49% lower in the burned portion of a woodlot compared with the unburned portion. However, risk of encountering nymphs infected with B. burgdorferi remained similar in both burned and unburned woods. It is suggested that burning vegetation may disproportionately kill deer-derived rather than rodent-derived nymphs, significantly reducing tick abundance without affecting transmission risk.     

Duration of Borrelia burgdorferi infectivity in white-footed mice for the tick vector Ixodes scapularis under laboratory and field conditions in Ontario

The duration of Borrelia burgdorferi infectivity in white-footed mice (Peromyscus leucopus) experimentally inoculated or infested with infected Ixodes scapularis nymphs was evaluated. Infectivity was assessed by infesting these mice with unfed I. scapularis larvae at 7, 21, 35 and 49 days post-inoculation (DPI) or post-infestation (PI). At 7 DPI, B. burgdorferi was transmitted from 18 of 24 syringe-inoculated mice and all three tick-infected mice to I. scapularis larvae which fed upon them. However, at 21, 35 and 49 DPI, significantly fewer mice were infective. Borrelia burgdorferi was isolated from tissues of 14 of 22 syringe-inoculated mice about 56 DPI, and from all three tick-infected mice. However, the level of agreement between xenodiagnosis and bacterial culture was no greater than would be expected by chance alone. We also determined if B. burgdorferi infectivity of mice varied in relation to periods of tick feeding in the field. White-footed mice were trapped during April, July and August 1993 from two habitats on Long Point peninsula (Ontario, Canada), where B. burgdorferi is endemic. Mice from each habitat were infested with laboratory-reared I. scapularis larvae. Ticks from each mouse were subsequently examined by immunofluorescent assay for B. burgdorferi infection and mice were cultured for B. burgdorferi. None of 3577 I. scapularis larvae fed on 62 mice captured within the cottonwood dune habitat were infected with B. burgdorferi, although it was isolated from six of these mice. Within the maple forest habitat, 0/24, 8/21 (38%) and 1/21 (5%) mice transmitted B. burgdorferi to I. scapularis larvae during April, July and August, respectively. Most mice from the maple forest with B. burgdorferi-positive tissues (14/21) were collected during July, although the level of agreement between xenodiagnosis and tissue culture was poor. Because B. burgdorferi infectivity in mice appears to be of short duration, overwintered I. scapularis larvae and nymphs may have to feed upon infected hosts at the same time of year in order for a cycle of B. burgdorferi infection to be maintained on Long Point. Infected I. scapularis nymphs, rather than persistently infected vertebrate hosts, likely serve as the overwintering "reservoir" for B. burgdorferi on Long Point.     

Therapeutic passive vaccination against chronic Lyme disease in mice

Passive and active immunization against outer surface protein A (OspA) has been successful in protecting laboratory animals against subsequent infection with Borrelia burgdorferi. Antibodies (Abs) to OspA convey full protection, but only when they are present at the time of infection. Abs inactivate spirochetes within the tick and block their transmission to mammals, but do not affect established infection because of the loss of OspA in the vertebrate host. Our initial finding that the presence of high serum titers of anti-OspC Abs (5 to 10 microg/ml) correlates with spontaneous resolution of disease and infection in experimentally challenged immunocompetent mice suggested that therapeutic vaccination with OspC may be feasible. We now show that polyclonal and monospecific mouse immune sera to recombinant OspC, but not to OspA, of B. burgdorferi resolve chronic arthritis and carditis and clear disseminated spirochetes in experimentally infected C.B.-17 severe combined immunodeficient mice in a dose-dependent manner. This was verified by macroscopical and microscopical examination of affected tissues and recultivation of spirochetes from ear biopsies. Complete resolution of disease and infection was achieved, independent of whether OspC-specific immune sera (10 microg OspC-specific Abs) were repeatedly given (4x in 3- to 4-day intervals) before the onset (day 10 postinfection) or at the time of fully established arthritis and carditis (days 19 or 60 postinfection). The results indicate that in mice spirochetes constitutively express OspC and are readily susceptible to protective OspC-specific Abs throughout the infection. Thus, an OspC-based vaccine appears to be a candidate for therapy of Lyme disease.     

Temporal pattern of Borrelia burgdorferi p21 expression in ticks and the mammalian host

The temporal synthesis of the P21 protein of Borrelia burgdorferi and the development of the humoral response to this antigen was assessed in infected mice. p21 is a member of the ospE-F gene family and its protein, P21, has been shown to be expressed by B. burgdorferi within infected mice but not by spirochetes cultured in vitro. P21 was not detected on B. burgdorferi in unfed or engorged Ixodes dammini (also known as I. scapularis) ticks, further supporting the postulate that P21 synthesis is specific for the mammalian host. In B. burgdorferi-infected mice, ospE mRNA and OspE antibodies were observed at 7 d, whereas p21 mRNA and P21-specific antibodies were detected at 21-28 d, suggesting that p21 is expressed later than ospE. Moreover, ospA mRNA was not discernible until day 14, indicating that ospA, like p21, is not expressed in the early stages of tick-transmitted murine Lyme borreliosis. Because p21 is expressed during infection in mice, we assessed the human humoral response to P21. 28% (34 of 122) of the patients with either early- or late-stage Lyme disease, and 33% (11 of 33) of the individuals with Lyme arthritis had P21 antibodies, suggesting that a P21 response may serve, at least partially, as a marker of infection. Active immunization with recombinant P21 did not protect C3H mice from tick-borne B. burgdorferi infection, and passive transfer of P21 antiserum to infected mice did not alter the course of disease. These data suggest that the antigenic structure of B. burgdorferi changes during the early stages of murine infection.     

Effect of prior exposure to noninfected ticks on susceptibility of mice to Lyme disease spirochetes

To determine whether prior exposure to Nearctic Ixodes vector ticks protects native reservoir mice from tick-borne infection by Lyme disease spirochetes, we compared their infectivities for white-footed mice and laboratory mice that had been repeatedly infested by noninfected deer ticks. Nymphal ticks readily engorged on tick-exposed laboratory mice, but their feeding success on white-footed mice progressively declined. Tick-borne spirochetes readily infected previously tick-infested mice. Thus, prior infestation by Nearctic ticks does not protect sympatric reservoir mice or Palearctic laboratory mice from infection by sympatric tick-borne spirochetes.     

Temporal correlations between tick abundance and prevalence of ticks infected with Borrelia burgdorferi and increasing incidence of Lyme disease

The abundance of host-seeking Ixodes scapularis nymphs, the principal vector for the Lyme disease agent, Borrelia burgdorferi, in Old Lyme, Lyme, and East Haddam, Connecticut, was compared with the incidence of reported human Lyme disease in the 12-town area around the Connecticut River and the State of Connecticut for the period 1989 to 1996. Ticks were sampled from lawns and woodlands by dragging flannel over the vegetation and examined for the presence of B. burgdorferi by indirect fluorescent antibody staining. The infection rate of the nymphal ticks by B. burgdorferi during the 9-year period was 14.3% (of 3,866), ranging from 8.6% (1993) to 24.4% (1996). The incidence of Lyme disease was positively correlated with tick abundance in the 12 town area (r = 0.828) and the State of Connecticut (r = 0.741). An entomological risk index based upon the number of I. scapularis ticks infected by B. burgdorferi was highest in 1992, 1994, and 1996 and was highly correlated with the incidence of Lyme disease in Connecticut (r = 0.944). The number of Lyme disease cases has been influenced, in part, by annual changes in population densities of I. scapularis and, presumably, a corresponding change in the risk of contact with infected ticks. Based upon tick activity and spirochetal infection rates, epidemiologically based Lyme disease case reports on a regional scale appear to reflect real trends in disease.     

DbpA, but not OspA, is expressed by Borrelia burgdorferi during spirochetemia and is a target for protective antibodies

DbpA is a target for antibodies that protect mice against infection by cultured Borrelia burgdorferi. Infected mice exhibit early and sustained humoral responses to DbpA and DbpB, suggesting that these proteins are expressed in vivo. Many antigens expressed in mammals by B. burgdorferi are repressed in vitro at lower growth temperatures, and we have now extended these observations to include DbpA and DbpB. To confirm that the protective antigen DbpA is expressed in vivo and to address the question of its accessibility to antibodies during infection, we examined B. burgdorferi in blood samples from mice following cutaneous inoculation. B. burgdorferi was visualized by dark-field microscopy in plasma samples from spirochetemic mice, and an indirect immunofluorescence assay showed that these spirochetes were DbpA positive and OspA negative. We developed an ex vivo borreliacidal assay to show that hyperimmune antiserum against DbpA, but not OspA, killed these plasma-derived spirochetes, demonstrating that DbpA is accessible to antibodies during this phase of infection. Blood transferred from spirochetemic donor mice readily established B. burgdorferi infection in naive recipient mice or mice hyperimmunized with OspA, while mice hyperimmunized with DbpA showed significant protection against challenge with host-adapted spirochetes. Antiserum from persistently infected mice had borreliacidal activity against both cultured and plasma-derived spirochetes, and adsorption of this serum with DbpA substantially depleted this killing activity. Our observations show that immunization with DbpA blocks B. burgdorferi dissemination from the site of cutaneous inoculation and suggest that DbpA antibodies may contribute to control of persistent infection.     

Lyme disease: self-regulation and pathogen invasion

Ecological interactions underlying the epidemic of Lyme disease involve a spirochete, a tick (with larval, nymph and adult stages), and two (or more) vertebrate hosts. Juvenile ticks ordinarily feed on mice; adult ticks feed on deer. Mice acquire the spirochete from infected nymphs and then pass the infection to larvae of the next tick generation. Lyme disease may result when a human is inadvertently bitten by an infectious nymph. Our model of the Lyme phenomenon counts the total number of ticks in each stage, the numbers of infected ticks by stage, and the number of infected mice. We fix the total population sizes of deer and mice, assume the ticks self-regulate, and solve the homogeneous-mixing case for equilibrium abundances. A local stability analysis identifies a condition where extinction of the spirochete is stable. Reversing this condition implies that the spirochete can invade the system of ticks and vertebrate hosts. When the spirochete can invade, a positive equilibrium number of infected organisms is locally stable. Spirochete invasion is promoted by a sufficient density of mice suffering low mortality, high susceptibility to infection in both mice and ticks, a high attack rate of ticks on mice, a high density of larval ticks, and low mortality among tick nymphs. Low mouse mortality allows the frequency of infection among nymphs to approach an individual tick's susceptibility when feeding on an infected mouse.     

Distribution and molecular analysis of Lyme disease spirochetes, Borrelia burgdorferi, isolated from ticks throughout California

Previous studies describing the occurrence and molecular characteristics of Lyme disease spirochetes, Borrelia burgdorferi, from California have been restricted primarily to isolates obtained from the north coastal region of this large and ecologically diverse state. Our objective was to look for and examine B. burdorferi organisms isolated from Ixodes pacificus ticks collected from numerous regions spanning most parts of California where this tick is found. Thirty-one isolates of B. burgdorferi were examined from individual or pooled I. pacificus ticks collected from 25 counties throughout the state. One isolate was obtained from ticks collected at Wawona Campground in Yosemite National Park, documenting the occurrence of the Lyme disease spirochete in an area of intensive human recreational use. One isolate from an Ixodes neotomae tick from an additional county was also examined. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis, immunoblot analysis, agarose gel electrophoresis, Southern blot analysis, and the polymerase chain reaction were used to examine the molecular and genetic determinants of these uncloned, low-passage-number isolates. All of the isolates were identified as B. burgdorferi by their protein profiles and reactivities with monoclonal and polyclonal antibodies, and all the isolates were typed by the polymerase chain reaction as North American-type spirochetes (B. burgdorferi sensu stricto). Although products of the ospAB locus were identified in protein analyses in all of the isolates, several isolates contained deleted forms of this locus that would result in the expression of chimeric OspA-OspB proteins. The analysis of OspC demonstrated that this protein was widely conserved among the isolates but was also quite variable in its molecular mass and the amount of it that was expressed.     

Erythema migrans-like rash illness at a camp in North Carolina: a new tick-borne disease?

BACKGROUND: Borrelia burgdorferi, the causative agent of Lyme disease, has never been isolated from a patient thought to have acquired Lyme disease in any southeastern state. OBJECTIVE: To investigate 14 cases of an erythema migrans (EM)-like rash illness that occurred during 2 summers at an outdoor camp in central North Carolina in an effort to determine the etiologic, epidemiological, and clinical aspects of this illness. METHODS: Using active surveillance, we identified cases of clinically diagnosed EM in residents and staff of the camp. We collected clinical and demographic information; history of exposure to ticks; acute and convalescent serum antibodies to B. burgdorferi, Rickettsia rickettsii, and Ehrlichia chaffeensis; and cultures for spirochetes from biopsy specimens of skin lesions. Serum samples from a group of residents and staff who did not develop rashes were tested for the same antibodies. We speciated ticks removed from people and collected from vegetation. RESULTS: We identified 14 cases of EM-like rash illness during the 2 summers. Of the 14 case-patients, 10 had associated mild systemic symptoms and 1 had documented fever. All 14 case-patients had removed attached ticks, and 8 remembered having removed a tick from the site where the rash developed a median of 12 days earlier (range, 2-21 days). One tick removed from the site where a rash later developed was identified as Amblyomma americanum, the Lone Star tick; 97% of ticks collected from vegetation and 95% of ticks removed from people were A. americanum. No spirochetes were isolated from skin biopsy specimens. Paired serum samples from 13 case-patients did not show diagnostic antibody responses to B. burgdorferi or other tick-borne pathogens. CONCLUSIONS: This investigation suggests the existence of a new tick-associated rash illness. We suspect that the disease agent is carried by A. americanum ticks. In the southern United States, EM-like rash illness should no longer be considered definitive evidence of early Lyme disease.     

Immunization with a polyvalent OspA vaccine protects mice against Ixodes ricinus tick bites infected by Borrelia burgdorferi ss, Borrelia garinii and Borrelia afzelii

Sequence variability of the outer surface protein (Osp) A among Borrelia burgdorferi sl species suggests that a monovalent OspA vaccine may not protect against the various Borrelia present in Eurasia. Here, we confirmed that a monovalent recombinant OspA (rOspA) vaccine does not protect mice against Ixodes ricinus mediated infection with B. burgdorferi ss, Borrelia garinii and Borrelia afzelii. However, when mice were vaccinated with a cocktail of various rOspA from these three species, they were protected, and all challenge ticks that fed on them were cleared of their spirochetes. These results showed that a multiple OspA antigens vaccine, compatible with human use, was very efficient at protecting mice against B. burgdorferi ss, B. garinii, and B. afzelii.     

Effects of low pH and nicotine on carotid body chemoreceptor activity in the rabbit

Ixodes scapularis ticks acquired spirochetes while cofeeding with Borrelia burgdorferi-infected nymphs (donors) on uninfected naive gerbils. Overall, 19% (67 of 345) of the recipient nymphs randomly exposed to gerbils with donor nymphs acquired spirochetes by fluorescent antibody (FA) tests, 18% (62 of 345) by the polymerase chain reaction. In a second experiment, donor nymphs were placed on the left ears, recipient nymphs were placed on the left and right ears, and xenodiagnostic larvae were placed on the gerbils' backs. Only recipient nymphs and larvae removed from the left ears were infected with B. burgdorferi. Infection rates were 47% (9 of 19), 87% (13 of 15) and 88% (14 of 16) in recipient nymphs placed on gerbils 0, 3, or 5 days after the donor nymphs, respectively, and 48% (12 of 25) in the larvae by FA analysis. Spirochetes appear to be acquired by cofeeding ticks from a localized infection near the feeding site rather than from a disseminated infection in the skin or blood.     

Infection rate of Ixodes ricinus ticks with Borrelia afzelii, Borrelia garinii, and Borrelia burgdorferi sensu stricto in Slovenia

In spring 1993, Ixodes ricinus ticks were collected from six regions of Slovenia to determine their overall rate of infection with Borrelia burgdorferi sensu lato and to assess the frequency of individual species in these tick populations. Ticks were dissected and midgut tissue inoculated into modified Barbour-Stoenner-Kelly (BSK II) medium. Borrelia isolates were differentiated into separate species using species-specific polymerase chain reaction (PCR) primers and by large restriction fragment pattern (LRFP) analysis. Infected ticks were found in all six regions surveyed. Spirochaetes were isolated from 69 of 363 ticks (19%): the isolation rate from adult female ticks was 35% (23/66 ticks cultured), from adult male ticks 22% (20/91), and from nymphal ticks 13% (26/206). Determination of the species of 60 isolates revealed that 32 were Borrelia afzelii (53%), 20 were Borrelia garinii (33%), and 8 were Borrelia burgdorferi sensu stricto (13%). In the Ljubljana region Borrelia afzelii and Borrelia garinii predominated (43% and 40%, respectively), whereas Borrelia burgdorferi sensu stricto constituted only 17% of isolates. In three other regions of the country Borrelia afzelii was isolated exclusively, although the number of isolates investigated was small. This study demonstrates the presence of all three European species of Borrelia burgdorferi sensu lato within the Slovenian tick population and also within a geographic area of less than 100 m2.     

Transmission of Borrelia burgdorferi s.l. from mammal reservoirs to the primary vector of Lyme borreliosis, Ixodes ricinus (Acari: Ixodidae), in Sweden

Factors regulating prevalence of Borrelia burgdorferi s.l. Johnson, Schmid, Hyde, Steigerwalt & Brenner in Ixodes ricinus (L.) were examined during 1991-1992 at Bogesund, near Stockholm in south-central Sweden. Nine species of small and medium-sized mammals (Sorex araneus L., S. minutus L., Neomys fodiens Pennant, Clethrionomys glareolus [Schreber], Microtus agrestis [L.], Apodemus sylvaticus [L.], A. flavicollis [Melchior], Lepus europaeus Pallas, L. timidus L.) were found to infect feeding tick larvae with B. burgdorferi s.l., whereas two species of large mammals (Capreolus capreolus L., Alces alces L.) failed to infect feeding tick larvae with this spirochete. The most important mammalian reservoirs at the study locality were S. araneus and rodents, accounting for 91% of all I. ricinus larvae infected. In view of the great number of potentially effective reservoirs for B. burgdorferi s.l. in Sweden, control of Lyme disease by reduction of abundance of reservoir hosts will be difficult to achieve. We also found that infectivity of a rodent species is related to the number of infesting, potentially infective nymphal I. ricinus. Insectivores and rodents were the most important hosts of larval I. ricinus, whereas most nymphal ticks fed on hares and cervids. Adult I. ricinus were frequently found on all species of hares and cervids examined but never on insectivores and rodents. No single species seemed to be of paramount importance as a source of blood for female ticks. Therefore, control of Lyme disease by reduction of abundance of mammal hosts available for female tick engorgement will probably require massive reductions of numbers of both C. capreolus and L. timidus.