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At least 55 records · Page 3Linked to original sources
PubMed1999

Granulocytic ehrlichiosis and tick infestation in mountain lions in California.

Forty-seven mountain lions (Puma concolor) collected year-round in 1996 to 1998 from the Sierra Nevada foothills, the northern coast ranges, and in Monterey County (California, USA) were examined for infestation with Ixodes pacificus and Dermacentor variabilis ticks. Ticks were found predominantly in winter and spring. The seroprevalence of granulocytic ehrlichiae (GE) antibodies (Ehrlichia equi or the agent of human granulocytic ehrlichiosis) was 17% and the PCR-prevalence of DNA characteristic of GE in blood was 16%. There were eight polymerase chain reaction (PCR)-positive but seronegative mountain lions, one that was PCR-positive and seropositive, and eight that were PCR-negative and seropositive. Nineteen percent of engorged tick pools from mountain lions were PCR-positive. Because mountain lions inhabit tick-infested habitat and are frequently bitten by I. pacificus, surveillance for GE antibodies and DNA in mountain lions and other vertebrate hosts may be useful as indicators for geographical regions in which humans are at risk of GE infection.

Age Factors↗
PubMed2005

Efficacy of a collar impregnated with amitraz and pyriproxyfen for prevention of experimental tick infestations by Rhipicephalus sanguineus, Ixodes ricinus, and Ixodes scapularis in dogs.

OBJECTIVE: To compare the efficacy of collars impregnated with 9% amitraz or 9% amitraz and 0.5% pyriproxyfen (PPF) for control of newly established tick infestations by Rhipicephalus sanguineus, Ixodes ricinus, and Ixodes scapularis in dogs and determine whether egg production by surviving female ticks was decreased. DESIGN: Prospective study. ANIMALS: 72 dogs. PROCEDURE: Dogs were fitted with 1 of 3 test collars impregnated with amitraz, amitraz and PPF, or only excipients (untreated controls). In 3 trials corresponding to each of the 3 tick species, dogs were infested with 150 unfed adult ticks on days 8, 10, 13, and 18. The number of feeding female ticks was recorded on days 10, 13, 18, and 28. Surviving females were weighed and permitted to oviposit under controlled conditions. RESULTS: Collars impregnated with amitraz and PPF decreased tick loads as efficiently as collars containing amitraz alone. Inclusion of PPF into the collar did not significantly decrease the efficacy of amitraz. The few female ticks that survived after feeding on dogs treated with collars containing PPF were unable to oviposit. CONCLUSIONS AND CLINICAL RELEVANCE: Collars impregnated with amitraz were efficient in preventing tick infestations in dogs but did not inhibit oviposition in the few surviving female ticks. Incorporation of PPF into the amitraz-impregnated collar resulted in impairment of the reproductive ability of ticks.

Animals↗
PubMed2001

Tick infestation of Borana cattle in the Borana Province of Ethiopia.

A study was conducted to identify and determine burdens of ticks infesting Borana cattle in the Borana Province of Ethiopia. Rhipicephalus pulchellus, Rhipicephalus pravus, Rhipicephalus muhsamae, Rhipicephalus praetextatus, Rhipicephalus evertsi evertsi, Amblyomma gemma, Amblyomma variegatum, Amblyomma cohaerens, Amblyomma lepidum, Hyalomma truncatum, Hyalomma marginatum rufipes and Boophilus decoloratus were identified on the cattle. Their burdens ranged from 658-1,554 with a mean of 1,205 ticks per animal. Out of the total 6,025 ticks collected, about 82% were R. pulchellus, followed by R. pravus (about 8%) and A. gemma (5%). The other nine species of ticks accounted for only 5% of the total burdens. It is suggested that a strategic tick control method, aimed mainly at reducing the R. pulchellus burdens, with the objective of allowing a reasonable number of ticks to remain on cattle for the maintenance of endemic stability to tick-borne diseases be instituted.

Animals↗
PubMed1981

The induction of host resistance to tick infestation with a salivary gland antigen.

Salivary gland antigen, SGA, derived from partially engorged female Dermacentor andersoni was shown to be capable of inducing resistance to tick infestation in guinea pigs never previously exposed to ticks. Immunization regimens involved the administration of SGA by different routes and with or without the use of adjuvants. Induced resistance was expressed by significantly fewer larvae engorging, and the weight of larvae which did engorge was reduced. Salivary gland antigen has been shown to interact with the immune effector elements of animals which acquired and expressed tick resistance due to infestation. These findings demonstrated the potential for an immunologic approach to tick control.

Adjuvants, Immunologic↗
PubMed2005

Tick infestations of the eastern cottontail rabbit (Sylvilagus floridanus) and small rodentia in northwest Alabama and implications for disease transmission.

Studies were conducted over a four-county area of northwest Alabama to determine the association of eastern cottontail rabbits with Dermacentor variabilis, the eastern United States vector of Rocky Mountain spotted fever. A secondary objective was to compare infestations of this tick on rabbits with infestations on commonly encountered rodent species as a means of determining the relative importance of each in the disease transmission cycle. These epidemiologic surveys were conducted in response to reported fatal cases of Rocky Mountain Spotted Fever in two counties of the study area. From 202 eastern cottontail rabbits, 3,956 ticks were collected. Of this total, 79.87% were Haemphysalis leporispalustris, 9.15% Amblyomma americanum, 8.22% Ixodes dentatus, and 2.76% D. variabilis. Only immature stages of D. variabilis were collected from cottontail rabbits. Ticks were collected on rabbits in all months except November, and only one specimen was taken in January. Based on the average number of ticks per host collected in each month, April was the peak month for D. variabilis and I. dentatus. High values for H. leporispalustris also occurred at this time, but even higher values occurred in October and December. The heaviest infestation of A. americanum occurred during the month ofAugust and coincides with the activity period for the larvae of this species. Two hundred sixty-nine of the smaller Rodentia, comprising 13 species, yielded 264 ticks, all D. variabilis, and all but two were immature stages. Five rodent species, Microtus ochragaster Orozomys palustris, Peromyscus gossypinus, Peromyscus leucopus, and Sigmodon hispidus accounted for 95.83% of the ticks collected, and appeared to be preferred hosts for D. variabilis; all five had higher infestation levels per host than did the eastern cottontail rabbit. Data on host relationships in association with seasonal activity are presented.

Alabama↗
PubMed1982

Scavenging dogs and the spread of tick infestation in Nigeria.

A dog, on whose body ticks were found early in January, 1977, was kept in the household during the night but allowed to scavenge during the day without the ticks being removed throughout the year. Weekly counts of the number of different stages of ticks found on the body were made and the behaviour of the engorged dropped ones was studied. The preoviposition, oviposition and preeclosion periods of replete ticks were also studied. Rhipicephalus sanguineus and Haemaphysalis leachi leachi were the only ticks found on the body; the former was more abundant but both occurred throughout the year with greater abundance during the rains. Completion of the life cycle was faster in both species during the dry season than the rainy season. Each stage of the life cycle was very prolonged during the harmattan. On dropping, adults showed an initial phase of inactivity, the length of which was influenced by the climatic season. While engorged larvae and nymphs could overcome impediments by waking round them, the adults appeared to be contended with ovipositing there. Some adult R. sanguineus were caught while attempting to bit a human bait. The public health significance of this fact as well as the role of scavenging dogs in aiding the dissemination and maintaining the population of ticks of dogs in Nigeria are discussed.

Adult↗
PubMed1992

Controlling tick infestations and diseases in sheep by pour-on formulations of synthetic pyrethroids. A field study.

The use of synthetic pyrethroids in pour-on formulations reduced tick infestations and the incidence of tick-associated diseases in lambs more than dipping in organophosphate acaricides. Though the use of pyrethroids did not prevent the lambs from being infected with tick-borne fever (TBF), the incidence of lambs with lameness (tick pyaemia) or lambs suddenly found dead (Pasteurella haemolytica septicaemia), which often are seen in association with TBF, was reduced. The use of pyrethroids for three years did not seem to affect the prevalence of TBF.

Administration, Topical↗
PubMed2004

Biology and control of ticks infesting dogs and cats in North America.

At least 15 different infectious agents and diseases are transmitted or produced by ticks parasitizing dogs and cats in North America. Those infectious agents and diseases are distributed among eight different tick species that commonly infest dogs and cats. All but one of these species are hard ticks with a three-host development cycle in which each motile stage (larva, nymph, and adult) feeds on a different host after molting. Tick species, disease occurrence, and peak activity of each tick life stage can vary dramatically depending on geographic and climatic conditions. Gaining an understanding of tick distribution, tick ecology, and seasonal occurrence of different tick life stages can help with the management of tick infestations and reduce the incidence of tick-transmitted diseases in dogs and cats. Control should be based on an understanding and management of ecologic factors responsible for tick infestations and selection of appropriate acaricides. Occasionally, topical acaricides will appear not to have prevented tick infestations. This lack of control may be real or perceived based on reinfestation rates and/or pet owner expectations of product performance.

Animals↗
PubMed1985

Effects of tick infestation on Boran (Bos indicus) cattle immunised against theileriosis in an endemic area of Kenya.

Boran (Bos indicus) heifers were immunised by infection with local Theileria parva parva, T p lawrencei and T mutans stocks and treated with parvaquone and later exposed to natural tick and tick-borne disease challenge in the Trans-Mara Division of Kenya. The Theileria species parasites in the challenge were maintained in African buffalo and cattle and the tick vectors were supported by several species of wild Bovidae and domestic livestock present in the area. Thirty immune cattle were observed for 30 weeks while grazing on a ranch in the Trans-Mara Division. Of these, 15 were immersed in toxaphene at weekly or twice-weekly intervals while 15 cattle remained without acaricide application. Cattle which became pregnant were withdrawn from the experiment. There was no evidence of any clinical tick-borne disease in either group of cattle during the experiment. Five species of ixodid ticks infested the cattle during the experiment and cattle which were not treated with acaricide had far more ticks. Rhipicephalus appendiculatus was the most abundant tick species, with a mean infestation of 46 adults per animal in the undipped cattle. This tick also appeared to be the cause of the observed reduction in weight gains. Major haematological parameters did not differ significantly between the groups. Behavioural studies showed that the undipped cattle spent less time grazing and ruminating. This study has shown that, at the expense of some loss in productivity, zebu cattle, immunised against ticks and theileriosis, can be kept despite tick infestation.

Animals↗
PubMed2000

Tick infestations of birds in coastal Georgia and Alabama.

Mist-netted birds were examined for ticks on Jekyll Island, Glynn Co., Georgia (32 bird species) in 1996-1998, and at Fort Morgan, Baldwin Co., Alabama (36 species) in 1998 during fall migration. Sixty-two (14.7%) of 423 birds from Jekyll Island and 22 (13.3%) of 165 birds from Fort Morgan were infested with ticks. The mean number of ticks per infested bird was 2.0 on Jekyll Island and 6.3 at Fort Morgan. Ten species of birds were infested with ticks on Jekyl1 Island where 87% of all ticks were recovered from 3 species: the common yellowthroat (Geothlypis trichas), gray catbird (Dumetella carolinensis), and northern waterthrush (Seiurus noveboracensis). Eight species of birds were infested with ticks at Fort Morgan where 83% of all ticks were recovered from 3 species: the brown thrasher (Toxostoma rufum), swamp sparrow (Melospiza georgiana), and common yellowthroat. Six species of ticks (Amblyomma americanum, Amblyomma maculatum, Haemaphysalis leporispalustris, Ixodes brunneus, Ixodes minor, and Ixodes scapularis) were recovered from the Georgia birds, whereas 3 species (A. maculatum, H. leporispalustris, and Ixodes dentatus) were recovered from the Alabama birds. Attempts to isolate Borrelia burgdorferi sensu stricto, the etiologic agent of Lyme borreliosis, from Ixodes spp. ticks recovered from birds were unsuccessful.

Alabama↗
PubMed1992

Influence of exposure period and management methods on the effectiveness of chickens as predators of ticks infesting cattle.

Experiments undertaken on Rusinga Island, Kenya, indicated that Rhipicephalus appendiculatus (Neumann) was the predominant tick consumed on tick-infested cattle by chickens, followed by Amblyomma variegatum (Fabricius), Boophilus decoloratus (Koch) and Rhipicephalus evertsi evertsi (Neumann). The number of ticks consumed by chickens released with cattle in a 3 h release period was not significantly different from ticks consumed in a 4 h release period. In a free management system, chickens 1-3 months of age consumed more ticks than older ones; in a confined management system however, chickens 4-6 months of age consumed more ticks than younger birds. Although the numbers of ticks consumed by local and exotic breeds of chickens were not significantly different, a period of 8-10 weeks was necessary for the exotic breeds to become behaviorally adapted to tick predation on cattle. Local chickens bred in environments where cattle were absent took a shorter period of 4-6 weeks to adapt. It was concluded that the relatively large number of ticks consumed by each chicken during the 3 or 4 h release period is an indication that a good reduction of ticks on cattle can be achieved through tick predation by chickens. The preponderance of R. appendiculatus over other tick species consumed was a reflection of its relative abundance on cattle on the island rather than a selective preference for tick species.

Animal Husbandry↗
PubMed1994

Tick infestations on cattle vaccinated with extracts from the eggs and the gut of Boophilus microplus.

Extracts prepared from the membranes of eggs (EM) and guts (GM) of Boophilus microplus were used to immunise cattle which were then infested twice with 20,000 larval ticks 1 week apart. EM antigens did not protect cattle against challenge with ticks, despite high levels of anti-egg antibodies in the sera of the vaccinated cattle, detected by an indirect enzyme-linked immunosorbent assay (ELISA). Cattle vaccinated with GM, however, had high levels of antibodies against GM and were protected significantly against challenge with B. microplus. Anti-EM and anti-GM antibodies in the sera of cattle cross-reacted significantly with GM and EM respectively on ELISA and recognised both specific and common antigens in extracts of the eggs and guts of B. microplus on Western blots. Exposure of cattle to field infestation with ticks during vaccination with gut antigens did not adversely affect the levels of antibodies generated.

Animals↗
PubMedDate not supplied

[Tick infestation and the prevalence of Borrelia burgdorferi and Babesia divergens in cattle in Bavaria].

During the grazing period 2002 319 cattle from 31 farms located in 6 districts of southern Bavaria were examined for the presence of ticks in 4- to 5-week intervals, and 287 serum samples were tested for the presence of antibodies against Borrelia burgdorferi and Babesia divergens. Ticks were detected in all 31 farms with a mean prevalence of 69%. 3218 out of 3453 collected ticks were Ixodes ricinus; 139 nymphs, 19 larvae and 77 damaged adult specimens could only be determined to the Genus level (Ixodes). The seasonal pattern revealed the highest frequencies of ticks in May/June and September. The intensity of tick infestation of positive animals was generally low. 76.5% of parasitized cattle had 1-6 ticks per day of investigation. Individual cattle showed up to 250 ticks per day. The percentage of infested animals in each herd varied within the period between 0-100%. The examination of serum samples by immunofluorescence technique (IFAT) revealed positive anti-Borrelia antibody titers (> or = 1:64) for 45.6% of the animals. The within-farm seroprevalence of borreliosis ranged from 20 to 100% in 27 of the 31 farms. A significant correlation could be detected between the number of ticks/cattle and the anti-Borrelia burgdorferi IgG-titer. By contrast, there was no significant correlation between the age of the animals and anti-Borrelia serum titers. For comparative reasons, 64 IFAT-positive serum samples were tested by Western blot techniques for the presence of antibodies cross-reacting with Borrelia garinii antigen. These analyses revealed that 69% of the samples reacted positively, 28% were unclear and 3% were negative. Examinations of the 287 serum samples for the presence of anti-Babesia divergens antibodies revealed one positive animal with a titer of 1:16.

Animals↗
PubMed1987

A seed tick infestation of the conjunctiva: Amblyomma americanum larva.

Ticks commonly infest humans but rarely bite the eyes. They are vectors of disease; therefore, rapid and complete removal is important. Their attachment can be so secure that removal is difficult or hazardous. We excised a larval form of Amblyomma americanum from a woodsman's conjunctiva.

Adult↗
PubMed2006

A case of histologically diagnosed tick infestation on the scalp of a Korean child.

A scalp mass surgically excised from a 4-year-old Korean boy was identified as a tick through histological observations. In sections of the mass, characteristic features of a tick, including its gross contour, cuticular structures, well developed musculature and salivary glands, and the capitulum, were discovered. In particular, the capitulum is anteriorly protruded, which strongly suggests that the specimen be a hard tick of family Ixodidae. However, the present histological features were not enough to determine the genus and species of the tick, because information on sectional morphologies of different tick species is unavailable. This is a rare case of tick infestation on the scalp diagnosed in histological sections.

Child, Preschool↗
PubMed2002

Seasonal abundance of adult ixodid ticks infesting cattle belonging to resource-limited farmers in the north-eastern Free State Province of South Africa.

A study was undertaken to determine the seasonal abundance of the ticks infesting cattle owned by resource-limited farmers in the north-eastern Free State Province of South Africa. Infestations of Boophilus decoloratus Koch, 1844, Rhipicephalus evertsi evertsi Neumann, 1897, Rhipicephalus follis Donitz, 1910, Rhipicephalus gertrudae Feldman-Muhsam, 1960 and Rhipicephalus warburtoni Walker & Horak, 2000, were monitored on cattle of mixed breeds at monthly intervals from May 1998 to April 1999. High tick intensity on the cattle was observed between March and June, with a peak in May to June 1998 for B. decoloratus and R. evertsi evertsi. Few ticks from the other three species were recovered from the cattle. Small peaks in November to December 1998 for R. warburtoni, and in December 1998 for R. follis and R. gertrudae were observed. Following the winter (June to August), numbers of B. decoloratus declined markedly, while those of R. evertsi evertsi and other rhipicephalids increased. These results represent the first published information on ticks of veterinary importance infesting cattle in the north-eastern part of the Free State Province.

Animal Husbandry↗
PubMed2002

Tick infestation of sika deer (Cervus nippon) in the western part of Yamaguchi Prefecture, Japan.

Ticks were collected from 94 sika deer (Cervus nippon) hunted in the western part of Yamaguchi Prefecture, Japan from August to November 1999, and March to July 2000. Haemaphysalis longicornis and H. yeni were the dominant species from April to August, while H. flava and H. megaspinosa were dominant in October, November and March. This is the first report of H. yeni in the mainland of Japan. Small numbers of H. kitaokai, Amblyomma testudinarium and Ixodes ovatus were also recorded.

Animals↗