Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Tick Control”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,531 records · Page 85Linked to original sources
PubMed1992

Absence of ovicidal effects of fenoxycarb in the tick Ixodes dammini as observed by light, scanning, and transmission electron microscopy.

Freshly oviposited eggs from fed females of the northern deer tick Ixodes dammini were divided into two groups--untreated controls and fenoxycarb-exposed ova. The level of fenoxycarb exposure in the experimental group was equal to a concentration that proved 100% lethal in the cat flea, Ctenocephalides felis (Marchiondo et al. 1990). Both groups were allowed to develop with samples taken at 48 and 144 h for examination by light microscopy, scanning electron microscopy, and transmission electron microscopy. No disruption of the stages of tick embryological development was observed when specimens were examined by these methods. Eggs not sampled for light microscopy or scanning or transmission electron microscopy during development were allowed to hatch. The resulting larvae were fully developed and motile in both the control and experimental conditions, further supporting the conclusion that embryological development of I. dammini is not disrupted by concentrations of fenoxycarb which would be practical in the field.

Animals↗
PubMed1992

Effects of the avermectin analogue MK-243 on vitellogenesis and reproduction in the ixodid tick, Amblyomma hebraeum.

A dose-dependent reduction in weight of total egg mass and a slightly increased oviposition latency were observed following injection of the avermectin analogue MK-243 (4"-epi-methylamino-4"-deoxyavermectin B1) directly into the haemocoel of engorged female Amblyomma hebraeum Koch (Acari: Ixodidae). Egg laying was almost completely inhibited at 100 micrograms/kg body weight. MK-243 markedly inhibited ovary development and vitellogenesis. Ticks treated with 100 micrograms MK-243/kg also had one-tenth the haemolymph ecdysteroid concentration compared to controls 10 days post-engorgement. Thus, among its other effects on ticks, the avermectins also inhibit the process of vitellogenesis.

Animals↗
PubMed2003

The influence of tick behavior, biotope and host specificity on concerted evolution of the platelet aggregation inhibitor savignygrin, from the soft tick Ornithodoros savignyi.

Ticks are obligate blood-feeding parasites that secrete anti-hemostatic components during feeding to enable control of the hemostatic system of the host. Complex interactions at the tick-host interface are an indication of the important role that the host played during tick evolution. The question is to what extent interaction with the host and the environment influences tick evolution. Previously, two isoforms (97% sequence identity) of savignygrin, an alphaIIbbeta3 antagonist, have been described. The presence of both isoforms within 20 random individuals confirmed that these isoforms must be recent gene duplicates. Analysis of the sequence differences between the isoforms shows a Kn/Ks ratio of 1, which indicates neutral selection for the isoforms. However, the biased localization of differences within the 3' end of the genes suggests that concerted evolution acts on the isoforms. Calculation of the divergence date between the isoforms (1.6-5.2 MYA) also indicates purifying selection, as ample time had passed after duplication, for inactivation of one gene copy. We conclude that concerted evolution has functioned to maintain a high copy number of the savignygrins in order for Ornithodoros savignyi to parasitize a wide host range. This contrasts with O. moubata that expresses the savignygrin homolog, disagregin, as a single copy at lower concentration levels and correlates with the confined habitat and consequently narrow host range of O. moubata. Recent "domestication" of O. savignyi due to animal husbandry practices could however, have reduced the selection constraints acting to maintain the gene copies as evidenced by the structural instability of one of the isoforms. Our results suggest that environmental factors and host associations do play an important role in the evolution of anti-hemostatic components in ticks.

Alleles↗
PubMed1994

Production and characterization of a polyclonal antiserum against Spiroplasma mirum (ATCC 29335).

Spiroplasma mirum (ATCC 29335), an American tick isolate, was cultivated and its purity was controlled using electron microscopy and Tricine-SDS-PAGE. In the SDS-PAGE analysis, the protein pattern of the antigen used revealed a polypeptide profile (35 bands) with an approximate molecular weight of 161 kDa to 10.5 kDa. This strain was used to immunize two rabbits. The produced antisera did not cross-react with Mycoplasma pneumoniae, Salmonella minnesota, Borrelia burgdorferi, Treponema pallidum but did still react in Western blot analysis with Spiroplasma mirum at a dilution of 1:128.000. This specific and sensitive antiserum was used to examine 72 midgut smears of Berlin ticks (lxodes ricinus) individually by direct immunofluorescence. In 26 samples, we could demonstrate fluorescent structures, but we were not able to culture spiroplasmas from these samples.

Animals↗
PubMed1988

Clinical and serologic evaluations of induced Borrelia burgdorferi infection in dogs.

Adult Beagles were used to evaluate clinical signs and serologic response after inoculation with, or exposure to, Borrelia burgdorferi. An indirect immunofluorescent assay (IFA) and 2 ELISA were used to monitor the serologic response to B burgdorferi. Feeding infected ticks on 4 dogs (group 1) failed to cause seroconversion, and SC inoculation with 500 organisms caused minimal seroconversion in 2 of 4 dogs (group 2). At 56 days, approximately 3.01 X 10(8) B burgdorferi organisms were injected IV into group-1 dogs, and intraperitoneally into group-2 dogs. A control group of 4 dogs (group 3) had noninfected ticks feed on them, and then were given IV injection of physiologic saline solution. Increases in immunoglobulin M (IgM) titers were detected in 2 of 4 group-2 dogs approximately 7 days after the initial exposure. These titers returned to negligible values 20 days later. Immunoglobulin G titers increased approximately 10 days after the initial exposure and were mildly increased 56 days later, when dogs were exposed a second time. Both the IV and intraperitoneal injections (second exposures) resulted in increased IgM titers, which in both groups eventually returned to preexposure values after approximately 2 months. Immunoglobulin G titers increased within a week after the second exposure, and in 3 dogs monitored for 8 months, returned to negligible values after the 8-month period. One control dog had a slightly increased IgG titer 24 days after the second inoculation. The possibility of urine transmission is suggested. Clinical status, hemograms, serum biochemical profiles, ECG and results of urinalyses remained normal throughout the study.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1997

Borrelia burgdorferi migrates into joint capsules and causes an up-regulation of interleukin-8 in synovial membranes of dogs experimentally infected with ticks.

Twenty 6-week-old specific-pathogen-free beagles were infected with Borrelia burgdorferi by tick challenge, and five uninfected dogs served as controls. During the study, all dogs were monitored for infection, clinical signs, and antibody response against B. burgdorferi. During episodes of lameness or postmortem, synovial fluids from each dog were examined for volume, cell number, polymorphonuclear leukocyte (PMN) content, cell viability, and chemotactic activity. Twenty-five tissues collected postmortem from each dog were tested for interleukin-8 (IL-8) mRNA, tumor necrosis factor alpha (TNF-alpha) mRNA, presence of live spirochetes, and histopathological changes. Thirteen infected dogs (group A), which seroconverted rapidly (maximum titers within 50 to 90 days), developed acute and severe mono- or oligoarthritis almost exclusively in the limb closest to the tick bite (median incubation period, 66 days). Synovial fluids of the arthritic joints collected during episodes of lameness had significantly elevated volume, cell count, PMN proportion, cell viability, and chemotactic activity for PMNs. The remaining joints of the same animals contained synovial fluids with elevated chemotactic activity and cell viability. Twelve dogs tested positive for IL-8 mRNA in multiple tissues (synovia, pericardium, and peritoneum), and 10 dogs expressed TNF-alpha mRNA, but only in the tributary lymph nodes of the inflamed joints. Histological examinations revealed severe poly- or oligoarthritis and moderate to severe cortical hyperplasia in draining lymph nodes of the inflamed joints in all 13 dogs. Seven infected dogs with mild or no clinical signs (group B) seroconverted slowly (peak titers after 90 days), and only some joint fluids showed chemotactic activity, which on average was lower than that in inflamed and noninflamed joints from dogs in group A. Four dogs expressed IL-8 mRNA (in the synovia and pericardium), and three dogs had TNF-alpha mRNA in tributary lymph nodes. Histologically, nonsuppurative arthritis was found in multiple joints, and mild to moderate cortical hyperplasia was found in draining lymph nodes. Five uninfected dogs without lameness (group C) had normal synovial fluids and tissues. In all infected dogs, live spirochetes were demonstrated more frequently in tissues of the somatic quadrant closest to the tick bite than in tissues further from the site of infection, suggesting that dissemination of B. burgdorferi occurs more by migration than by blood-borne spread. From these studies employing a canine model of B. burgdorferi infection, we conclude that IL-8 is involved in the pathogenesis of acute Lyme arthritis.

Animals↗
PubMed2001

Lyme disease--United States, 1999.

Lyme disease (LD) is caused by the tickborne spirochete Borrelia burgdorferi sensu lato and is the most common vectorborne disease in the United States. Surveillance for LD was initiated by CDC in 1982, and the Council of State and Territorial Epidemiologists designated it a nationally notifiable disease in January 1991. This report summarizes the number of LD cases reported to CDC during 1999. Although the number of cases decreased from 1998, the number of cases in 1999 was higher than the number reported during the early 1990s. LD can be prevented by avoiding tick-infested habitats, by using personal protective measures, by vaccination, by checking for and removing ticks attached to the body and clothes, and by reducing tick populations.

Adolescent↗
PubMed1994

Stimulation of attachment in a camel tick, Hyalomma dromedarii (Acari: Ixodidae): the unintended result of sublethal exposure to permethrin-impregnated fabric.

The susceptibility of a camel tick, Hyalomma dromedarii (Koch), to permethrin-impregnated military uniform fabric was studied to determine the effects of laundering and contact time. Separate contact toxicity tests were conducted with laboratory-colonized male and female ticks of uniform age. Unfed, unmated ticks were exposed for periods of 5, 10, 30, and 60 min to each of five fabrics: unwashed-untreated, unwashed-treated, and 1, 2, or 3 times washed after treatment (1-, 2-, 3-wash-treated). Treated fabric was impregnated with permethrin at 0.125 mg (AI)/cm2. Laundering was by machine washing with detergent followed by hot air machine drying. Intoxication immediately after exposure was assessed by activity response: the proportion of ticks attaching to a host (rabbit) within 60 min and the average time elapsed between contact and insertion of mouthparts. Unexpectedly, permethrin exposure activated an attachment response in both sexes. At all contact times, and in each wash-treated group, a greater proportion of ticks attached, and did so more rapidly, than in controls. Mortality assessment 24 h after exposure showed that females were more tolerant than males and experienced light mortality even after 60 min of contact. Both natural and acquired factors may account for permethrin tolerance in this species. Consistent with pyrethroid mode of action and pheromone function in ticks, it is hypothesized that sublethal levels of permethrin may act on H. dromedarii to induce premature or excess release of a neurosecretory substance that elicits attachment.

Animals↗
PubMed2005

[Serum and cerebrospinal concentrations of sICAM-1 sICAM-2, sICAM-3 in neuroborrellosis and tick borne encephalitis--preliminary report].

OBJECTIVE: The aim was to evaluate the concentrations of the soluble forms of ICAM-1, ICAM-2, ICAM-3 in the serum and cerebrospinal fluid (CSF) of patients with neuroborreliosis and thick borne encephalitis before and after therapy in comparison with the control group. MATERIAL AND METHODS: We examined 30 patients, 10 in each group: neuroborreliosis-group I (NB), tick borne encephalitis--group II (TBE) and in the control group (group K). The diagnosis of neuroborreliosis and TBE based on the clinical features was confirmed by ELISA assays: FSME Virus/TBE Virus test (VIRION, Germany) for TBE and Borrelia IgM and IgG Recombinant (Biomedica Austria) for NB. The assays of sICAM-1, sICAM-2, sICAM-3 (ELISA, Bender Med System, USA) were performed twice in group I and II: before and after 3-4 weeks long treatment and once in control group. RESULTS AND CONCLUSIONS: Increased concentration of soluble forms of ICAM-1, ICAM-2, ICAM-3 in CSF suggest their important role in inflammatory process of viral and bacterial origin. In NB group, the serum concentrations of sICAM-1, sICAM-2 were significantly increased before and after treatment in comparison with control as well as with the analogous test results in TBE group. It may suggest NB as the part of systemic inflammation. The CSF concentration of sICAM-2 decreases after treatment in NB group in comparison with the analogous test results of TBE group. The increased CSF concentration of sICAM-2 in TBE group when compared to the CSF concentration in NB group suggest slow recovery and still persisting immunological activation in this group, even when the neurological symptoms disappeared. Increased concentrations in CSF in both diseases indicate intrameningeal activity of lymphocytes and may be a useful marker of inflammation.

Adult↗
PubMed1999

[Risk of tick-borne encephalitis (TBE) virus infection among people occupationally exposed to tick bites].

The paper presents the results of seroepidemiologic studies concerning tick-borne encephalitis (TBE) in 1583 persons (1261 forestry workers and 233 farmers) from the Lublin region (eastern Poland) occupationally exposed to ticks and in 130 healthy blond donors (a control group). The mean percentage of seropositive reactions in forestry workers amounted 19.8% and in farmers 32.0%. Based on 5-year research (1994-1998) conducted in 5 districts of the Lublin region, an existence of endemic foci of TBE was detected in the district of Biała Podlaska, on the areas of Radzyñ Podlaski and Parczew, where the percentage of seropositive reactions in forestry workers exceeded 50%. Statistical analysis showed that the frequency of seropositive reactions in forestry workers and farmers was significantly greater compared to control group (p<0.001 and p<0.05, respectively). It indicates that these groups are occupationally exposed to TBE wirus. Totally, in the years 1994-98 nine clinical cases of TBE (acute neuroinfection) in forestry workers and fourteen clinical cases in farmers were confirmed serologically. The effectiveness of specific immunization against TBE was proved on the brie of 100% seroconversion in 56 earlier seronegative forestry workers. The obtained results proved that forestry workers and farmers in Poland are under increased risk of infection with TBE virus.

Adult↗
PubMed1998

Seroepidemiologic study on tick-borne encephalitis among forestry workers and farmers from the Lublin region (eastern Poland).

The paper presents the results of seroepidemiologic studies concerning tick-borne encephalitis (TBE) in 1,583 persons (1,261 forestry workers and 233 farmers) from the Lublin region (eastern Poland) occupationally exposed to ticks and in 130 healthy blood donors (a control group). The mean percentage of seropositive reactions in forestry workers amounted to 19.8% and in farmers 32.0%. Based on 5-year research (1994-1998) conducted in 5 districts of the Lublin region, the existence of endemic foci of TBE was detected in the district of Bia a Podlaska, on the areas of Radzyń Podlaski and Parczew, where the percentage of seropositive reactions in forestry workers exceeded 50%. Statistical analysis showed that the frequency of seropositive reactions in forestry workers and farmers was significantly greater compared to control group (p < 0.001 and p < 0.05, respectively). It indicates that these groups are occupationally exposed to TBE virus. In the years 1994-98, a total of nine clinical cases of TBE (acute neuroinfection) in forestry workers and fourteen clinical cases in farmers were confirmed serologically. The effectiveness of specific immunization against TBE was proved on the basis of 100% seroconversion in 56 earlier seronegative forestry workers. The obtained results proved that forestry workers and farmers in Poland are under increased risk of infection with TBE virus.

Adult↗
PubMed1989

Permethrin-impregnated bednets reduce nuisance arthropods in Gambian houses.

The prevalence of bedbugs (Cimex hemipterus L.), chicken ticks (Argas persicus Oken) and headlice (Pediculus capitis De Geer) was surveyed in a rural area of The Gambia. At the beginning of the study 37.5% of children's beds were infested with bedbugs and 3.9% with chicken ticks, whilst the prevalence rate of pediculosis in children under 10 years old was 28.8%. Both bedbugs and headlice were clustered within compounds. Headlice prevalence increased with hair length and they were more common on girls than boys. Following this cross-sectional survey all bednets in the sixteen hamlets were either dipped in permethrin or a placebo. About 4 months later it was found that bedbugs and chicken ticks had disappeared from homes in which the bednets had been impregnated with permethrin. There was no reduction in hamlets with placebo-treated bednets. The rate of acquiring headlice between the two surveys was reduced by 91.1% in children who slept under insecticide-treated bednets compared with children with placebo-treated bednets. There were also significantly fewer day-flying and crawling insects, except earwigs, in homes of children who slept under insecticide-treated bednets compared with those with placebo-treated nets. These additional benefits of permethrin-treated bednets should contribute to their widespread acceptance and utilization by the community for personal protection.

Animals↗
PubMed1999

Temporal relation between Ixodes scapularis abundance and risk for Lyme disease associated with erythema migrans.

Understanding the role that nymphal and female ticks, Ixodes scapularis, have in the epidemiology of Lyme disease is essential to the development of successful prevention programs. In this study, the authors sought to evaluate the seasonal and annual relations between tick densities and patients > or = 16 years of age diagnosed with erythema migrans (EM), the rash associated with early Lyme disease. Ticks were collected weekly by drag sampling throughout most of the year from 1991 to 1996 in Westchester County, New York. The number of EM cases was based on patients diagnosed at the Westchester County Medical Center using Centers for Disease Control and Prevention (CDC) criteria. No patients with EM were diagnosed from January through April, when only adult ticks were active. Correlation analysis between monthly tick densities and EM incidence was significant for nymphs (r = 0.87, p < 0.01), but not for adult ticks (r = -0.57, p > 0.05). There was a strong, although not significant, correlation between peak annual number of patients with EM and peak nymphal tick abundance (r = 0.76, p = 0.08). These data indicate that bites from adult I. scapularis only rarely result in Lyme disease, and that annual nymphal tick abundance determines exposure. This suggests that annual fluctuations in Lyme disease case numbers are largely due to natural changes in tick abundance and, therefore, that control of nymphal I. scapularis should be a major component of Lyme disease prevention efforts.

Adult↗
PubMed2001

Anti-interleukin-8 activity of tick salivary gland extracts.

Interleukin-8 (IL-8) is one of many mammalian chemokines (chemotactic cytokines) that direct mammalian inflammatory and immune cells to sites of injury and infection. Chemokines are produced locally and act on leucocytes through selective receptors. The principal role of IL-8 is to control the movement and activity of neutrophils. To date, several tick species have been shown to modulate the production or activity of certain cytokines but none of these are chemokines. Using an IL-8 specific ELISA, we showed that salivary gland extracts (SGE) from several ixodid tick species (Dermacentor reticulatus, Amblyomma variegatum, Rhipicephalus appendiculatus, Haemaphysalis inermis and Ixodes ricinus) reduced the level of detectable IL-8. Analyses of fractionated SGE revealed one similar peak of activity for D. reticulatus, A. variegatum and R. appendiculatus; a second peak, observed for D. reticulatus and A. variegatum, differed between the two species. Using radiolabelled IL-8, SGE and peak activity fractions of D. reticulatus were shown to bind the chemokine, and to inhibit binding of IL-8 to its receptors on human granuolocytes enriched for neutrophils. The biological significance of these observations was demonstrated by the ability of SGE to inhibit IL-8 induced chemotaxis of human blood granulocytes. Future isolation and characterization of the active molecules will enable determination of their functional roles in bloodfeeding and effect on tick-borne pathogen transmission.

Animals↗
PubMed1998

Contact toxicity of permethrin-impregnated fabric to Hyalomma anatolicum excavatum (Acari: Ixodidae): effects of laundering and exposure and recovery times.

A previous study that documented enhanced host attachment by the camel ticks Hyalomma dromedarii Koch after permethrin exposure prompted a similar investigation of permethrin effects in H. anatolicum excavatum Koch, an Old World hardbacked tick suspected of vectoring human pathogens. Contact toxicity tests were conducted with laboratory-colonized male and female H. a. excavatum of the same age exposed for periods of 5, 10, 30, and 60 min to each of 5 fabric treatments: unwashed/untreated; unwashed and treated; and treated fabric given 1, 2, or 3 laundry cycles of warm-water detergent machine washing, followed by hot-air drying. Fabric was tropical weight 100% cotton military uniform. Treated fabric was impregnated with permethrin at 0.125 mg (AI)/cm2. Contact toxicity was measured immediately after and 24 h after fabric contact as proportion of ticks that attached mouthparts to the skin of a host (rabbit) within a 60-min quest period and time lapse (minutes) between contact with the host and attachment. Attachment response immediately after permethrin contact was exposure time- and wash-dependent in both sexes. Proportion of attaching ticks and times to attachment were comparable in controls and in groups exposed to all permethrin-treated fabrics for 5 or 10 min. Contact periods of 30 and 60 min with 0-wash/treated or 1-wash and treated fabric significantly reduced the frequency of attachment and significantly prolonged mean times to attachment. Compared with low levels of attachment response observed immediately after fabric contact, recovery of attachment response was observed 24 h after exposure in these wash/treatment groups, but inhibition was still evident. Permethrin-induced intoxication was more pronounced in males than females. Mortality 24 h after exposure was only significant among females exposed to 0-wash/treated fabric for 60 min. There was no evidence of permethrin-mediated stimulation of the attachment response in H. a. excavatum.

Animals↗
PubMed2000

Seasonal distribution and abundance of ticks (Acari: ixodidae) in northwestern Florida.

A 2-yr study was conducted in a northwestern Florida state park and recreation area to determine tick species composition, seasonal abundance, and spatial distribution. Risk of tick attachment to park visitors was also assessed relative to tick abundance from several habitats. Tick collections consisted of weekly cloth drag samples obtained from ground and emergent vegetation along a deer trail, a walking trail located in a 3-mo-old control burned area of forest, a nonburned walking trail, picnic area, and campsites. Sampling was conducted from February 1994 through February 1996. Ticks collected during the study were as follows in descending order of abundance: Ixodes scapularis Say, Amblyomma americanum (L.), A. maculatum Koch, and Dermacentor variabilis (Say). Significantly more (<0.05) adult ticks were recovered from vegetation compared with ground samples only for I. scapularis. Adult questing I. scapularis were collected from October through May (peak December). A. americanum adults were collected from March through August (peak May). Adult A. maculatum were collected during August and September and adult D. variabilis were collected July and August. Larval and nymphal stages of questing A. americanum were collected from June through November (peak July) and February through October (peak September), respectively. A. maculatum nymphs were collected from February through April, June, and September (peak March). No nymphs of I. scapularis were collected. Only four larvae of D. variabilis were collected during the study, all during February 1995. No I. scapularis or A. maculatum larvae were collected from vegetation or ground drags. The greatest risk for tick attachment was in campsites where approximately 60% of all adult and nymphal host-seeking ticks were collected. The next greatest risk area was the walking trail located in the control burned area where an additional 28% of ticks were obtained.

Animals↗