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 1,135 records · Page 63Linked to original sources
PubMed2004

The prevalence of serum antibodies to tick-borne infections in Mbale District, Uganda: the effect of agro-ecological zone, grazing management and age of cattle.

Between August and October 2000, a cross-sectional study was conducted in smallholder dairy farms in Mbale District, Uganda to assess the prevalence of ticks and tick-borne diseases under different grazing systems and agro-ecological zones and understand the circumstances under which farmers operated. A questionnaire was administered to obtain information on dairy farm circumstances and practices. A total of 102 farms were visited and sera and ticks were collected from 478 animals. Sero-prevalence of tick-borne diseases was determined using an enzyme-linked immunoassay. Acaricides were used indiscriminately but the intensity of their use varied with the grazing system and zone. Cattle from different farms mixed for various reasons. During the dry seasons farmers have to get additional fodder from outside their farms that can result in importation of ticks. The prevalence of ticks and serum antibodies to tick-borne infections differed across the grazing systems and zones. The highest serum antibody prevalence (>60%) was recorded in the lowland zone under the free range and tethering grazing systems. The lowest tick challenge and serum antibody levels (<50%) were recorded in the midland and upland zones under a zero-grazing system. These findings suggest that endemic stability to East Coast Fever, babesiosis and anaplasmosis is most likely to have existed in the lowland zone, particularly, under the tethering and free-range grazing systems. Also, endemic stability for babesiosis existed in the upland zones. Endemic instability for East Coast Fever existed in the midland and upland zones. These structured observational studies are instrumental in planning of control strategies for ticks and tick borne diseases since production systems and the cattle population at high risk of the diseases in the district have been identified.

Aging↗
PubMed2005

A study of the acaricidal properties of an essential oil extracted from the leaves of Ageratum houstonianum.

Study on acaricide property of foam soap containing essential oil of Ageratum houstonianum leaves was tested on Rhipicephalus lunulatus. Four doses of the oil (0.00, 0.02, 0.025 and 0.03 microl/g) with four replications for each dose were used in vitro. Each replication consisted of 10 ticks in a Petri dish with filter paper impregnated uniformly with the foam soap on the bottom. The same four doses in three replications were used in vivo. Each replication was made up of 10 naturally ticks infested goats. Results of this study indicate that foam soap containing essential oil of A. houstonianum leaves is toxic to R. lunulatus. The in vitro mortality rate was observed to vary from 0 to 50% on day 8 after treatment with the controls as compared to 95% with the lowest dose (0.02 microl/g) on day 8 and 100% with the highest dose (0.03 microl/g) on day 3. Meanwhile, the in vivo mortality rate was observed to be 23.4% with the control on day 8 after treatment whereas the highest dose killed 95.1% of the ticks by this day. The LD50 of the foam soap containing essential oil of this plant was 0.0259 and 0.0173 microl/g on day 2 after treatment, in the laboratory and on the farm, respectively. This indicates a potentially high efficiency of this medicated soap on this parasite.

Ageratum↗
PubMed2002

Increasing risks of introduction of heartwater onto the American mainland associated with animal movements.

Opportunities to introduce heartwater onto the American mainland through animal movements include importation from Africa of tick-infested reptiles and of subclinically infected wild ungulates and importation of livestock from islands in the Caribbean infested with Amblyomma variegatum ticks. Measures to control importation of heartwater vectors on reptiles include importation bans of infested species, treatment of imported reptiles, and eradication of established infestations on the American mainland. Measures to control importation of infected wildlife must focus on improved methods, such as the PCR assay, of screening animals to prevent the entry of carriers of Cowdria ruminantium. Measures to control importation of infected animals from the Caribbean must be based on knowledge of the islands that are infected with C. ruminantium so that the risk of dissemination of heartwater can be established.

Africa↗
PubMed1990

Immunization of guinea-pigs against Rhipicephalus appendiculatus adult ticks using homogenates from unfed immature ticks.

Guinea-pigs immunized with homogenates of unfed larvae and nymphs of the tick Rhipicephalus appendiculatus developed significant levels of protective immunity to infestation with adults of this species. The mean engorged weight of female ticks feeding on immunized animals (181.96 +/- 05.63 mg and 170.11 +/- 11.54 mg) was reduced by an average of 46% and 51%, respectively, compared to that of female ticks feeding on control guinea-pigs, although in some individual animals the reduction was as high as 86%; the mean egg mass weight was also significantly reduced. Electrophoretic separation of the homogenates followed by immunostaining with post-infestation sera revealed several antigen bands common to all stages. Two bands of 36,500 and 23,000 molecular weight (MW) were recognized in all homogenates by post-adult infestation serum, but not by post-larval or post-nymphal infestation sera, suggesting that these may be antigens specifically involved in feeding by adult ticks, and are either not presented to the host's immune system or presented only in minimal amounts during feeding by immature stages. Sera from animals immunized with the homogenates did not recognize either of these antigens. Post-immunization sera did, however, stain two bands of 84,000 and 60,000 MW in the homogenates which were not recognized by post-infestation sera.

Animals↗
PubMed1994

Control of tsetse flies in Uganda by dipping cattle in deltamethrin.

The effect of treating cattle with deltamethrin to control tsetse flies and ticks was investigated on 2 ranches 8 km apart in central Uganda where there is a high risk of trypanosomosis. This area had a moderate challenge of Glossina pallidipes. The cattle had very low challenge of Rhipicephalus appendiculatus, Amblyomma variegatum, Boophilus decolaratus and Rhipicephalus evertsi evertsi, due to regular treatment with dioxathion. On one ranch a dip was charged with deltamethrin to treat cattle regularly for 3 months. The other ranch was used as a control for the tsetse population, but the animals continued to be treated regularly with dioxathion using hand sprays. On the ranch using deltamethrin treatment a reduction of 96.9% in the tsetse population was recorded after 2 treatments at 2 week intervals. Total (100%) control of tsetse was achieved from the fourth treatment up to the end of the trial period. The ranch with dioxathion treatment experienced an overall tsetse reduction of 19.15% during the thirteenth to fifteenth weeks and the factors contributing to this are discussed. However, the mean apparent tsetse density of 4.83 flies/trap/day recorded at the control ranch was significantly different from the mean of 0.81 flies/trap/day (P < 0.001) at the ranch using deltamethrin treatment. It was difficult to assess the effect of this product on ticks because of lack of controls. However, there are indications that deltamethrin can also reduce tick populations and the incidence of tick-borne diseases. The possible limitations and practical implications associated with large scale use of this product in the country are discussed.

Animals↗
PubMed1985

Acquisition and expression of resistance by Bos indicus and Bos indicus X Bos taurus calves to Amblyomma americanum infestation.

Purebred and crossbred Bos indicus calves were infested 1, 2, or 3 times with 10 female and 5 male Amblyomma americanum. Resistance was acquired by both the purebred and the crossbred calves after 1 infestation and resulted in statistically significant decreases in the percentages of females that engorged, the mean weights of engorged females, and the mean weights of egg masses. Comparisons between breeds of the percent of female ticks that engorged during the first and second infestations indicate that purebred B. indicus expressed a stronger acquired resistance to A. americanum more readily than did crossbred animals. However, calves of both genetic compositions displayed similar levels of resistance during a third exposure. All tick-exposed and control animals were skin tested with salivary gland extracts of A. americanum, A. cajennense and Dermacentor andersoni. Control, uninfested calves, did not display significant cutaneous reactivity to these extracts. All calves that had been infested had immediate, 30-min, 5-hr and delayed, 24-hr, skin reactions to Amblyomma species antigens. Reactions to D. andersoni salivary antigens in tests of both purebred and crossbred calves with acquired resistance to A. americanum suggest that Amblyomma species salivary gland antigens might have cross reactive moieties with a salivary extract prepared from D. andersoni. Peripheral blood lymphocyte in vitro responsiveness to Amblyomma species antigens was detected in purebred calves after a first, second, and third infestation, indicating the presence of cells of the immune system capable of recognizing and undergoing blast transformation in response to tick salivary components.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

The prehatch period and larval survival of Boophilus decoloratus (Koch, 1844) (Acarina: Ixodidae) under natural conditions in the Transvaal, South Africa.

Studies were made on the duration of the prehatch period of Boophilus decoloratus and on the subsequent survival and viability of larvae under natural conditions. The length of the prehatch and larval survival periods was found to be inversely dependent on increased temperature. A high initial temperature at the time of female drop decreased the prehatch period further, resulting in synchronous hatching of eggs laid at different times. Oviposition occurred but no eggs hatched during mid-winter months with mean temperatures below 10 degrees C. Eggs laid after mid-winter hatched because of the higher temperatures during subsequent months. Diapause occurs at the egg stage in areas with mean winter temperatures below 10 degrees C. Larvae survived for 10-35 weeks during periods of high and low seasonal temperatures respectively. Larval viability decreased concomitantly with larval survival. The results suggest that pasture spelling alone would be impractical as a control measure for this tick species.

Animals↗
PubMed2003

Development, characterization, and lethal effect of monoclonal antibodies against hemocytes in an adult female tick, Ornithodoros moubata (Acari: Argasidae).

In the present study, 19 monoclonal antibodies (mAbs) against adult Ornithodoros moubata hemocytes were established, and the reactivity of the hemocytes to these mAbs was examined by an indirect fluorescent antibody test (IFAT), Western blot and immunoprecipitation analyses. It was shown that the reactivities of the hemocytes to the mAbs varied among morphologically similar hemocyte types, and most mAbs produced in the present study showed the multiple band reactivity. However, the presence of shared epitopes among peptide subunits of the same protein or entirely different proteins are not common, so their reactivity could not be explained in detail. These results suggest that there are morphologically similar but functionally differentiated hemocytes. Therefore, in addition to morphological classification, the molecular-based classification of the hemocytes is also required. In order to assess the lethal effect of blood meal containing each mAb, artificial feeding was performed. The OmHC 31 showed the strongest lethal effect on adult female O. moubata. In conclusion, anti-hemocyte mAbs produced in this study are useful not only for the immunological classification of hemocytes but also for the immunological control of the tick.

Animals↗
PubMed1992

[Transfusion-associated non-A, non-B, non-C hepatitis caused by flaviviruses].

Hepatitis C virus was shown to be a member of the flavivirus family. Tick-borne encephalitis virus and West Nile virus, members of the same family occur in Hungary, too. Serum samples from patients suffering from transfusion associated hepatitis were tested with yellow fever virus antigens for specific IgG, and IgM using immunofluorescence test. Eight hundred serum samples were tested. Yellow fever virus related IgG antibodies were found in 232 sera. In the case of 72 patients specific IgM antibodies could also be detected. The majority of the IgM positive patients underwent surgical operation and/or blood transfusion 1 to 2 months before the onset of the disease. Fifty-four sera positive for yellow fever virus-related antibodies were tested with HCV reagents, but only 13 were found to be positive, or cross-reacting. The 20 patients with yellow fever related antibodies were controlled with tick-borne encephalitis antigens, too. Nevertheless, no measurable cross-reaction could be detected. No measurable cross-reaction could be detected with the West Nile virus. The hepatitis B markers also were tested in 44 sera positive for yellow fever antibodies. There was only one, which contained HBsAg, and 10 of them proved to be positive for anti-HBcAg. The results indicate, that a non-A, non-B, non-C flavivirus is also present in the Hungarian population, which can be detected on the basis of the antigenic cross-reactivity with the attenuated yellow fever virus. This virus seems to be responsible for every 11th transfusion associated hepatitis examined.(ABSTRACT TRUNCATED AT 250 WORDS)

Flavivirus↗
PubMed2000

Immunity reduces reservoir host competence of Peromyscus leucopus for Ehrlichia phagocytophila.

Infection with Ehrlichia phagocytophila in white-footed mice is transient and followed by a strong immune response. We investigated whether the presence of acquired immunity against E. phagocytophila precludes white-footed mice from further maintenance of this agent in nature. Mice were infected with E. phagocytophila via tick bite and challenged either 12 or 16 weeks later by Ixodes scapularis nymphs infected with the same agent. Xenodiagnostic larvae fed upon each mouse simultaneously with challenging nymphs and 1 week thereafter. Ticks were tested for the agent by PCR, and the prevalence of infection was compared to that in ticks that fed upon nonimmune control mice. Only 30% of immunized mice sustained cofeeding transmission of E. phagocytophila between simultaneously feeding infected and uninfected ticks, compared to 100% of control mice. An average of 6.3% of xenodiagnostic ticks acquired Ehrlichia from previously immunized mice when fed 1 week after the challenge, compared to 82.5% infection in the control group. Although an immune response to a single infection with E. phagocytophila in white-footed mice provided only partial protection against reinfection with the same agent, the majority of mice were rendered reservoir incompetent for at least 12 to 16 weeks. Immunity acquired by mice during I. scapularis nymphal activity in early summer may exclude a large proportion of the mouse population from maintaining E. phagocytophila during the period of larval activity later in the season.

Animals↗
PubMed1998

Immunization of rabbits against Hyalomma anatolicum anatolicum using homogenates from unfed immature ticks.

Antigens were prepared from unfed larvae and nymphs of H. a. anatolicum as homogenised antigens (HLAg and HNAg, respectively). Five rabbits each were inoculated, s.c. with 8.56 mg HLAg and 9.34 mg HNAg in 3 divided doses. Following immunisation rabbits developed significant level of protective immunity to infestation with adults of this species. Significant reduction in engorged percentage and weights of engorged females and egg masses were observed in females fed on immunized rabbits, compared to that of female ticks fed on control rabbits. The engorgement period was also increased significantly. However, conversion efficiency indices remained unaffected. Larval antigen immunized rabbits showed significant antibody level from 28-126 days while with HNAg elevated antibody levels were recorded up to 112 days. Further, the rabbits immunized with HLAg had elevated level of antibodies against HLAg, HNAg, and adult antigen in ELISA. But HNAg immunized rabbits had lower levels of antibodies against HLAg and HAAg as compared to values recorded against HNAg. Anti-HLAg and anti-HNAg sera recognised common antigenic bands of 97.4, 85, 66, 47.3, 42 and 31 kDa in homogenates of larvae, nymphs and adults.

Animals↗
PubMed1991

Effect of ivermectin on the volume of blood ingested by two species of ticks (Acari: Ixodidae) feeding on cattle.

Females of the lone star tick, Amblyomma americanum (L.), and the American dog tick, Dermacentor variabilis (Say), were fed on ivermectin (Ivomec)-treated and untreated bovines to determine the effect of the acaricide on volume of blood ingested and to compare the weight differences between the treatment and control groups at various time intervals after attachment. Adult females from each genus were collected from Bos tarus hosts and subjected to hematin assays on three collection dates to estimate the volume of blood ingested. Before feeding, lone star ticks contained an average of 2.0 microliters of blood and had an average weight of 5.2 mg. Unengorged American dog tick females had an average blood volume of 3.3 microliters and a mean weight of 5.8 mg. Ticks of both species reacted to ivermectin by expressing lower mean weights, and they consumed smaller quantities of blood. Lone star tick females were significantly affected in terms of amount of blood consumed and body weight changes when compared with control ticks. After feeding on treated cattle, lone star tick females contained smaller quantities of blood than pretreatment females, but there were no significant differences observed until day 12 between the control and the treated groups. American dog tick females on treated hosts had measurable quantities of blood that were significantly different among the experimental groups.

Animals↗
PubMed2005

Repellent efficacy of four commercial DEET lotions against Amblyomma hebraeum (Acari: Ixodidae), the principal vector of Rickettsia africae in southern Africa.

African tick bite fever, caused by Rickettsia africae, is an emerging zoonotic infection in rural sub-Saharan Africa and the French West Indies. We tested the repellent efficacy of four commercial diethyl-3-methylbenzamide (DEET) lotions against Amblyomma hebraeum Koch, the principal vector of R. africae in southern Africa, by using a human bioassay in which repellent-treated fingers were presented to questing tick nymphs hourly for 4h. Three lotions with 19.5, 31.6 and 80% DEET concentrations, respectively, had a repellent efficacy of > or =90% at 1h post-application, of > or =77% at 2h post-application and of <70% during the rest of the experiment. By contrast, a lotion with 2% DEET plus 1% citronella oil provided only a 59% repellency at 1h post-application, with a drop to <22% during the following hours. Hourly negative control trials repelled <5% of tick attacks. Our results suggest that commercial repellents containing > or =19.5% DEET provide a significant but short-lasting protection against questing A. hebraeum ticks.

Administration, Topical↗
PubMed1987

Control of induced infestations of adult Amblyomma hebraeum with sustained release ivermectin.

The efficacy of ivermectin, administered in a sustained release formulation by intraruminal pumps at approximate daily dose rates of 20, 40 and 60 micrograms/kg, was evaluated in 16 cattle against induced infestations of 3 strains of adult Amblyomma hebraeum. Engorged female ticks were mass-measured and incubated, and reproductive data recorded. There was an increase in mortality of male and female ticks compared to that of controls with increasing daily dose of ivermectin, and a decrease in the number of ticks engorging. Ticks fed on ivermectin-treated cattle had a smaller mass when engorged and laid smaller egg masses, both absolutely and as a proportion of engorged mass. Index of reproduction was reduced 100% at 60 micrograms/kg/day, greater than 99% at 40 micrograms/kg/day and 96% at 20 micrograms/kg/day. Differences occurred between the 3 strains of A. hebraeum used in the study, especially with regard to engorged mass and reproductive variables. Practical implications of the application of sustained release ivermectin for the control of A. hebraeum, specifically with reference to heartwater (Cowdria ruminantium), are discussed.

Animals↗
PubMed2002

Adult tick burdens and habitat use of sympatric wild and domestic ungulates in a mixed ranch in Zimbabwe: no evidence of a direct relationship.

Ticks do not usually infest sympatric hosts species according to their availability in a given environment, and it has been suggested that habitat use by hosts is a major determinant of tick burdens. The knowledge of such infestation patterns and their relationship with host habitat use is important for the control of the vectors of some major stock diseases in Africa, particularly in the context of mixed game/cattle ranching. In a ranch of Zimbabwe, we monitored the number of adult ticks found on cattle and wild ungulates. Tick burdens were measured weekly during one year on 12 heifers of an experimental herd (no acaricide used), and on wild ungulates occasionally shot for meat. Adult ticks were not evenly distributed among wild hosts, and infestation patterns corresponded to observations made by several authors in similar conditions. However, these infestation patterns could not be related to habitat use by ungulates, which had been previously monitored by road transect at the scale of the ranch, as these authors found a high niche overlap and no habitat segregation between ungulate species. In an attempt to relate habitat use by Brahman and Simmental heifers with the number of adult ticks collected during one day of grazing, we followed the heifers and recorded their position and activity (one or two days per week; each recording session was 7 h 30 min on average, for a total of 940 hours of survey). No correlation was found between the number of ticks collected and the distance (or time spent) traveled in each vegetation type or the number of grooming episodes. The possible role of other behavioral and physiological parameters is discussed, and the results are compared with those found for other tick-host associations.

Animals↗
PubMed2000

Possible risk factors on Queensland dairy farms for acaricide resistance in cattle tick (Boophilus microplus).

A case control study was carried out within a cross-sectional survey designed to investigate the management by Queensland dairy farmers of the cattle tick Boophilus microplus. Although 199 farmers were surveyed, data on acaricide resistance were only obtained from 66 farms. Multiple models were used to predict the probability of acaricide resistance associated with 30 putative risk factors. The region of the state in which the farm was located and the frequency of acaricide application were consistently associated with acaricide resistance. The risk of resistance to all synthetic pyrethroids (Parkhurst strain) was highest in Central Queensland and increased when more than five applications of acaricide were made in the previous year, when spray races were used and when buffalo fly treatments with a synthetic pyrethroid were applied frequently. The probability of resistance to amitraz (Ulam strain) was highest in Central Queensland, increased when more than five applications of acaricide were made in the previous year, and decreased on farms when a hand-spray apparatus was used to apply acaricides to cattle. The probability of resistance to flumethrin (Lamington strain) was highest in the Wide Bay-Burnett region.

Animals↗
PubMed1991

Borrelia burgdorferi: another cause of foodborne illness?

Borrelia burgdorferi was identified as the etiological agent of Lyme disease in 1982. This Gram-negative spirochete is classified in the order Spirochaetales and the family Spirochaetaceae. The pathogen is fastidious, microaerophilic, mesophilic and metabolises glucose through the Embden-Meyerhof pathway. A generation time of 11 to 12 h at 37 degrees C in Barbour-Stoenner-Kelly medium has been reported. Lyme disease, named after Lyme in Connecticut, is distributed globally. It is the most commonly reported vector-borne disease in the United States, where the incidence is highest in the eastern and midwestern states. Since establishment of national surveillance in 1982, there has been a nine-fold increase in the number of cases reported to the U.S. Centers for Disease Control. The deer tick of the genus Ixodes is the primary vector of Lyme borreliosis. The tick may become infected with B. burgdorferi, by feeding on an infected host, at any point in its 2-year life cycle which involves larval, nymphal and adult stages. The infection rate in deer ticks may be as high as 40% in endemic areas. The primary vertebrate reservoirs for Ixodes are the white-footed mouse (Peromyscus leucopus) and the white-tailed deer (Odocopileus virginianus). Dairy cattle and other food animals can be infected with B. burgdorferi and hence some raw foods of animal origin might be contaminated with the pathogen. Recent findings indicate that the pathogen may be transmitted orally to laboratory animals, without an arthropod vector. Thus, the possibility exists that Lyme disease can be a food infection. In humans, the symptoms of Lyme disease, which manifest themselves days to years after the onset of infection, may involve the skin, cardiac, nervous and/or muscular systems, and so misdiagnosis can occur.

Animals↗