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PubMed2002

Relationship between tick bites and the seroprevalence of Babesia microti and Anaplasma phagocytophila (previously Ehrlichia sp.) in blood donors.

BACKGROUND: Tick-borne diseases, particularly babesiosis and ehrlichiosis, represent recently emerging infections. Despite an increased recognition of the threat tick-borne agents pose to blood safety, our understanding of the prevalence and transmissibility of these agents in blood donors is limited. STUDY DESIGN AND METHODS: Babesia microti and Anaplasma phagocytophila (previously Ehrlichia sp.) seroprevalence was determined in random Connecticut and Wisconsin donors, and subsequently in Connecticut donors reporting tick bites. In the interim, a postcard survey regarding tick bites during the previous 6 months was sent to 6,000 random donors in six geographically distinct collection regions. RESULTS: In total, 3 of 999 Wisconsin donors (0.3%) and 6 of 1,007 Connecticut donors (0.6%) had antibodies to B. microti. Of 992 donors tested for A. phagocytophila, 5 Wisconsin donors (0.5%) and 35 Connecticut donors (3.5%) were seropositive. A total of 2,482 donors (41.4%) completed the survey; 103 (4.1%) reported a tick bite. Of 848 Connecticut donors (0.4%) reporting tick bites, 3 had B. microti antibodies, while 8 (0.9%) had A. phagocytophila antibodies. These rates were not significantly different from control donors. CONCLUSION: Blood donors seropositive for B. microti and A. phagocytophila are present in Connecticut and Wisconsin. Donors readily recall previous tick bites, but self-reported bites are not reliable indicators of serologic status. The exposure of blood donors to tick-borne pathogens does suggest a need to better understand the transfusion transmission potential of these agents.

Anaplasma phagocytophilum↗
PubMed1980

Exposure of cattle immunised against redwater to tick challenge in the field: challenge by a homologous strain of B divergens.

A field trial was conducted in Northern Ireland to determine whether calves could be protected against babesiosis by the prior inoculation of irradiated blood infected with Babesia divergens; The trial involved 30 yearling calves. Ten were inoculated with infected blood from a donor calf after the blood had been irradiated at 25 kilorads, and 10 with blood irradiated at 30 kilorads. Their reactions to the inoculation were observed daily for a month. They were then released, along with a control group of 10 susceptible calves, into an area heavily infested with B divergens-infected Ixodes ricinus ticks for two months. Between 24 and 41 days after exposure all the control animals contracted babesiosis and six of them reacted severely. None of the immunised animals suffered clinical babesiosis although 14 had detectable low-level infections. The relative severity of the reactions of the groups of calves was reflected in their haematology.

Animals↗
PubMed1986

Tick (Dermacentor albipictus)-induced winter hair-loss in captive moose (Alces alces).

Five captive moose calves each infested with 42,000 larval Dermacentor albipictus, six calves each infested with 19,000-21,000, and five control moose were observed for changes in hair-loss, body condition and number, stages, and distribution of the tick. Winter hair-loss was observed only in moose infested with ticks and was correlated positively with the total number of adult ticks. Hair-loss associated with ticks was minimal from October to January, but rapidly increased from February to April when up to 44% of hair had been removed. The pattern of hair-loss was similar in all moose with the neck, shoulders, withers, and perianal areas losing the most hair. Moose with extensive premature hair-loss had less pericardial and abdominal visceral fat than moose with little or no hair-loss.

Animals↗
PubMed2004

Increased expression of Borrelia burgdorferi factor H-binding surface proteins during transmission from ticks to mice.

The spirochete Borrelia burgdorferi is transmitted to humans and other warm blooded animals through the bites of infected Ixodes species ticks. Our studies indicate that these spirochetes utilize a quorum sensing mechanism to control protein expression patterns that involves the chemical signal autoinducer-2 (AI-2). Through this mechanism, a population of Lyme disease spirochetes may synchronize production of proteins needed for infection processes. AI-2 is produced by the B. burgdorferi LuxS protein, which we have demonstrated to be a functional enzyme. It has also been previously reported that luxS message is upregulated in feeding nymphal ixodid ticks. Among the B. burgdorferi proteins regulated through AI-2 are the complement inhibitory factor H binding Erp lipoproteins. We now report Erp protein expression is also increased during transmission of B. burgdorferi from nymphal ticks to mammalian hosts. Essentially no B. burgdorferi within unfed nymphal ticks expressed Erps, while almost all transmitted bacteria were Erp positive. These studies suggest that B. burgdorferi within feeding nymphal ticks produce AI-2 to coordinate expression of mammalian infection associated proteins, such as the factor H binding Erp lipoproteins. Binding of mammalian host factor H by Erps may then help promote bacterial dissemination through host tissues.

Animals↗
PubMed2003

Functional analysis of a G protein-coupled receptor from the southern cattle tick Boophilus microplus (Acari: Ixodidae) identifies it as the first arthropod myokinin receptor.

The myokinins are invertebrate neuropeptides with myotropic and diuretic activity. The lymnokinin receptor from the snail Lymnaea stagnalis (Mollusca) has been the only previously identified myokinin receptor. We had cloned a G protein-coupled receptor (AF228521) from the tick Boophilus microplus (Arthropoda: Acari), 40% identical to the lymnokinin receptor, that we have now expressed in CHO-K1 cells. Myokinins at nanomolar concentrations induced intracellular calcium release, as measured by fluorescent cytometry and the receptor coupled to a pertussis toxin-insensitive G protein. Absence of extracellular calcium did not inhibit the fluorescence response, indicating that intracellular stores were sufficient for the initial response. Control cells only transfected with vector did not respond. We conclude that the tick receptor is the first myokinin receptor to be cloned from an arthropod.

Amino Acid Sequence↗
PubMed2006

Effect of forest clearing on the abundance of Ixodes ricinus ticks and the prevalence of Borrelia burgdorferi s.l.

Questing Ixodes ricinus L. (Acari: Ixodidae) ticks were collected on a forest trail that had been completely cleared of shrubs and ground vegetation in winter 2002 and on a nearby control uncleared forest transect in South Moravia (Czech Republic). Samples were collected each May in 2003, 2004 and 2005. Nymphal ticks were 3.4 times, 1.9 times and 1.2 times less frequent on cleared forest than on uncleared forest trails in the three respective years, whereas adult tick abundance was 27.2 times, 4.0 times and 2.2 times lower, respectively. The ticks were examined for borreliae by dark-field microscopy: prevalence of nymphal ticks infected with Borrelia burgdorferi sensu lato (12.6% to 20.0%) did not differ significantly between the cleared and uncleared trail during the 3 years. In conclusion, the habitat modification appeared to result in a decreased abundance of I. ricinus as well as a reduced frequency of infected ticks (and thus indirectly a lower potential risk of Lyme borreliosis), which lasted, however, for only 2 years. Eight cultures of borreliae isolated from the ticks were all identified as the 'ornithophilic' genomic species Borrelia garinii, possibly indicating a greater role of forest birds than that of forest rodents as the hosts of immature I. ricinus in the tick (and borrelial) colonization of the cleared part of the forest.

Animals↗
PubMed1994

Vaccines against arthropods.

The possibility of vaccinating hosts against blood-feeding arthropods using antigens derived from salivary gland, gut, and other tissues is reviewed. These vaccines directed against vector arthropods also have the potential to effect the arthropods capacity to transmit pathogens, and this is distinct from transmission-blocking vaccines that use antigens derived from pathogens. Antigen extracts have been used in attempts to vaccinate against fleas, lice, keds, flies, mosquitoes, and a number of tick species. A vaccine against the cattle tick, Boophilus microplus (Canestrini), using a recombinant antigen, has been tested under field conditions. Ticks feeding on vaccinated hosts are damaged by an immune response directed against their gut cells. Some die on the host, others engorge but their fecundity is reduced. The Commonwealth Scientific Industrial Research Organization-Biotechnology Australia tick vaccine against B. microplus is cited as a model for the development of other vaccines. It is suggested that the weaker effects of vaccines against insects as compared with ticks are related to the different structure and physiologies of the gut rather than being related to time spent on the vertebrate host. These differences in the effects of vaccines on insects may favor vaccines which block the passage of pathogens into vector insects. Vaccines against mosquitoes have been shown to reduce susceptibility of mosquitoes to arboviruses. The potential of the different vaccines is discussed.

Animals↗
PubMed2006

Seroprevalence of human granulocytic anaplasmosis in Berlin/Brandenburg, Germany: an 8-year survey.

This study investigated the seroprevalence of antibodies against Anaplasma phagocytophilum in Berlin/Brandenburg, north-eastern Germany. During 1994-2001, 422 sera from patients with proven tick-exposure (specimens with antibodies against Borrelia burgdorferi) were compared with 249 control sera. Using indirect fluorescent antibody testing, significantly more positive samples were detected among Borrelia antibody-positive specimens (4.5%, 95% CI 2.5-6.5%) than among controls (1.2%, 95% CI 0.5-1.9%; p < 0.05). While six (2.2%, 95% CI 1.3-3.1%) samples were positive among Borrelia antibody-positive sera between 1994 and 1997, 13 (8.7%, 95% CI 6.9-10.5%) were positive between 1998 and 2001 (p < 0.01), indicating an uneven annual seroprevalence.

Adolescent↗
PubMed2001

The evaluation of yeast derivatives as adjuvants for the immune response to the Bm86 antigen in cattle.

BACKGROUND: The Gavac vaccine against the cattle tick Boophilus microplus has proven its efficacy in a large number of controlled and field experiments. However, this vaccine could be further improved by searching for new alternative adjuvants that would induce a stronger long-lasting immune response. We conducted several experiments to assay the adjuvant effect of fractions of the recombinant yeast Pichia pastoris in mouse and cattle models. In previous experiments, the combination of the yeast membrane with saponin was the most effective formulation in stimulating the humoral immune response in mice, eliciting a response higher than Montanide 888. The response was predominantly of the IgG1 isotype. Here, we evaluated the response in cattle and compared the results with that obtained in mice. RESULTS: Bm86 on the membrane of P. pastoris plus saponin produced high antibody titers in cattle, though the protection level against tick infestations was lower when compared to Gavac, probably due to a decrease in the IgG1/IgG2 ratio. The predictive value of the mouse model was studied through correlation analysis between the isotype levels in mice and the efficacy of formulations in cattle. Good correlation was established between the level of antibodies in mice and cattle, and between the amount of anti -Bm86 IgG1 in mice and the degree of protection in cattle. CONCLUSION: Mouse model have the potential to predict immunogenicity and efficacy of formulations in cattle. These results also support the use of the yeast expression system for recombinant vaccine formulations, enabling the prediction of more cost--effective formulations.

Adjuvants, Immunologic↗
PubMed1985

Mechanisms of resistance to chemicals in arthropod parasites of veterinary importance.

This review evaluates the significance, for ectoparasites, of the four resistance mechanisms that have emerged in arthropods as defence against chemicals used for their control. In particular the contrast of the relative importance of each mechanism in each of the major ectoparasitic pests of economic importance (sheep blowflies, mosquitoes and ticks) is discussed. Use is made of the experience gained in attempting to overcome these mechanisms to assess the consequences of resistance, and the chances for prolonging the useful life of pesticides, by suppressing the mechanisms, as an alternative to seeking replacement compounds.

Animals↗
PubMed1998

Seroepidemiologic study on Lyme borreliosis in the Lublin region.

The frequency of anti-Borrelia burgdorferi antibodies in human sera of various groups of people from the Lublin region was studied. In the indirect immunofluorescence test (IFT) sera from 836 forestry workers and 56 farmers occupationally exposed to ticks were examined. Fifty healthy blood donors from the city of Lublin were examined as a control group. Forestry workers showed positive response in 26%, whereas farmers in 11% and the control group in 6%. In ELISA test, sera from 44 forestry workers, 217 farmers, 458 patients from the dermatologic and neurologic clinics, and 50 blood donors (controls) were examined. A positive response was found in 38.6% of forestry workers, 28.1% of farmers, 12.2% of patients of the neurologic clinic, 27.1% of patients of the dermatologic clinic and in 6% of controls. During this study, in one of an forestry workers the diagnosis of Lyme borreliosis as the occupational disease was clinically confirmed. High percent of anti-Borrelia burgdorferi antibodies found in people exposed to ticks may suggest that Borrelia burgdorferi is widespread in the forest environment of eastern Poland and that infection often has an occupational character.

Agricultural Workers' Diseases↗
PubMed1989

Resistance to Rhipicephalus evertsi evertsi in immunosuppressed rabbits.

Rabbits treated with goat anti-rabbit thymocyte serum acquired less resistance to Rhipicephalus evertsi evertsi infestation than untreated controls. This inferior resistance was manifested as higher engorged weights of ticks and higher biotic potential, undue persistence of the ticks on the hosts and poor anti-tick antibody and delayed-type hypersensitivity responses. These observations highlight the significance of host T-cells in mediating resistance to ticks.

Animals↗
PubMed2002

Detection of the Anaplasma centralevaccine strain and specific differentiation from Anaplasma marginale in vaccinated and infected cattle.

Bovine anaplasmosis caused by the intraerythrocytic rickettsia Anaplasma marginale is the most prevalent tick-borne disease of cattle worldwide. The most efficient method to control anaplasmosis is by vaccination using live Anaplasma centrale, a closely related species or subspecies of low pathogenicity that is capable of inducing significant protection against the more virulent A. marginale. In the present study, we applied PCR assays to detect and discriminate field infection with A. marginale from A. centrale persistently infected vaccinates. Direct and one-stage nested PCR were based on A. centrale mbp58 specific sequence, with the assay sensitivity level of 0.00001% for nested PCR performed in a single amplification step. Size polymorphism in the A. marginale msp1 alpha gene among strains was used to design a PCR capable of discriminating between the Israel T and NT strains of A. marginale and the encoded MSP1a size polymorphism was confirmed by immunoprecipitation. The detection of A. centrale in 72% of vaccinated field-grazing cattle clearly indicated that the majority of vaccinated cattle remain carriers. A. marginalewas detected in 64% of these vaccinated cattle, demonstrating that, as expected, natural transmission occurs within the endemic region. The lack of severe A. marginaleoutbreaks in this region, despite ongoing transmission, is consistent with protection being provided by widespread vaccination with A. centrale.

Anaplasma↗
PubMed1994

[Serologic diagnosis of infections caused by Borrelia burgdorferi].

This investigation was aimed at selection of optimal serological test for diagnosis of borreliosis occurring at our territory. In our investigations, and indirect immunofluorescence test (IF) was used in which antigen consisted of an American strain of Borrelia burgdorferi B31 and immunoenzymatic test (IE) with an antigen prepared from an European strain. Hundred sixty eight sera were tested, including 138 sera received from patients with suspection of borreliosis or directed for testing because of suspected tick bite. Thirty sera from healthy blood donors served as a control. In 30 out of 138 patients with suspected borreliosis presence of specific antibodies in IF or IE test was detected. In control group positive results were obtained in 4 persons. From our study comparing two tests occurs that more suitable for serodiagnosis of borreliosis on our territory is determination employing as an antigen the European strain of Borrelia burgdorferi.

Antibodies, Bacterial↗
PubMed2004

Human anaplasmosis in north-eastern Poland: seroprevalence in humans and prevalence in Ixodes ricinus ticks.

Sera of 500 inhabitants of north-eastern Poland, 450 suspected for Lyme borreliosis and 50 blood donors (control group), were analysed for the presence of IgG antibodies against Anaplasma phagocytophilum, the causative agent of human anaplasmosis (HA), known so far as human granulocytic ehrlichiosis (HGE). Forty one (9.1 %) sera of the study group and one serum (2 %) of the control group were positive using indirect fluorescence assay (IFA). The seropositivity tended to be more frequent among males (10.3 %) than females (7.6 %) and among the rural (10.3 %) than urban population (7.5 %); however, differences were of no statistical significance (p = 0.4). No age difference was found between the seropositive and the seronegative individuals (p = 0.77). The only factor increasing the risk of HA seropositivity found was forestry employment (p < 0.05). Additionally, a total of 559 Ixodes ricinus ticks, collected in the same area as sera, were investigated for the presence of A. phagocytophilum by the polymerase chain reaction (PCR) and 41 (8.7 %) of them were found to be positive. The infection level ranged from 2.3-13.7 %, depending on the area studied. Bacteria were significantly less frequently detected in nymphs - 2.1 % (5/235) than in adult ticks - 13.6 % (44/324) and in males--4.2 % (74/165) than in females--23.3 % (37/159) (p < or = 0.05). The obtained results confirm both the occurrence of HA foci in north-eastern Poland with I. ricinus as the principal vector of the A. phagocytophilum infection, and forestry workers as the main group at risk.

Adult↗
PubMed2000

[Early-summer meningo-encephalitis (ESME) and ESME-vaccination: status 2000].

Tick-borne encephalitis (TBE) is a public health problem very well under control in Austria because of a vaccination programme using a safe, efficient and well tolerated vaccine and a carefully designed social marketing concept. The Austrian vaccine underwent another technological updating and is now marketed under a new brand name (TicoVac) on the basis of an EU registration. A second product is also available (Encepur), but some limitations of use have to be taken into account. To improve the epidemiological situation even further (only 41 hospital cases in 1999) special attention has to be given to the age group 50 years and older as this is the segment of the population where the majority of cases is observed. TBE is a growing international health problem as awareness increases and cases are identified in many European countries, even in regions where TBE so far was not diagnosed. An "International Scientific Working-group on Tick-borne encephalitis (ISW-TBE)" was established to coordinate research and public health activities.

Adult↗