PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Tick Infestations”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 109 records · Page 6Linked to original sources
PubMed1998

Ixodid tick infestations of wild birds and mammals on a game ranch in central province, Zambia.

Ticks were collected at irregular intervals from December 1995 to November 1996 from wildlife on Mtendere Game Ranch in the Chisamba District of Central Province, Zambia. Total collections were made from two species of ground-nesting birds and 20 species of small and large mammals. Thirteen species/subspecies of ixodid ticks were recovered. Rhipicephalus appendiculatus was the most abundant, followed by Boophilus decoloratus and Rhipicephalus evertsi evertsi. Small numbers of immature ticks of only a few species were collected from the birds and rodents. The lagomorphs carried large numbers of predominantly immature R. appendiculatus. Most of the ungulates harboured several tick species and had high infestations of R. appendiculatus. The seasonal abundances of Amblyomma variegatum, B. decoloratus, R. appendiculatus and R. evertsi evertsi were determined.

Animals↗
PubMed2003

Ehrlichiosis in anemic, thrombocytopenic, or tick-infested dogs from a hospital population in South Brazil.

Ehrlichia canis has a worldwide distribution, but clinical manifestations may vary geographically. We selected 129 dogs to determine prevalence of ehrlichiosis in dogs with anemia, thrombocytopenia, or ticks presented to a Veterinary Teaching Hospital in South Brazil. Of the 129 dogs, 68 carried the brown dog tick (Rhipicephalus sanguineus), 61 had thrombocytopenia (platelet count <150,000/microl), and 19 had anemia (PCV < 22%). Twenty dogs fulfilled more than one inclusion criteria. Ehrlichiosis was diagnosed by positive amplification of ehrlichial DNA by PCR using primers ECC and ECB that amplify a sequence of the 16S rRNA gene. Presence of E. canis was confirmed by cleavage of the amplified DNA using endonucleases HaeIII and AvaI. Fourteen of 68 (21%) dogs with ticks had ehrlichiosis, whereas 12 of 61 (20%) dogs presented with thrombocytopenia and 4 of 19 (21%) anemic dogs had ehrlichiosis. Similar results were obtained in dogs with thrombocytopenia and anemia (one of eight positive) and in dogs with thrombocytopenia and ticks (two of seven positive). All four dogs with anemia and ticks, and the dog that fulfilled all inclusion criteria yield no amplification of ehrlichial DNA by PCR. Based on our results, one in each five dogs infested by the brown dog tick, with anemia or thrombocytopenia had ehrlichosis. Contrary to widespread believe, ehrlichiosis was not the main cause for thrombocytopenia in our region.

Anemia↗
PubMed1985

Effects of tick infestation on the plaque-forming cell response to a thymic dependent antigen.

Strain-2 guinea-pigs were given two five-day infestations with Dermacentor andersoni larvae. Each exposure consisted of 100 larvae, and the first and second infestations were separated by a seven-day tick-free period. Tick-exposed animals were given an intravenous injection with sheep red blood cells (SRBC) at selected times during and after infestation: (a) the last, fifth day, of a first exposure, (b) the second day of a second infestation, (c) the fifth day of a second infestation and (d) four days after termination of the second infestation. Ability of these animals to respond immunologically to the SRBC injection was assessed by the direct haemolytic plaque-forming cell assay, a very sensitive test used to determine the number of spleen cells producing IgM to SRBC target cells. Strain-2 animals given SRBC at the end of an initial infestation, or during a second tick exposure, produced significantly fewer direct haemolytic plaque-forming cells than did uninfested controls given a similar SRBC immunization regimen. Spleen cells of animals administered SRBC on the fourth day after termination of a second infestation displayed a haemolytic plaque-forming cell response which did not differ significantly from that of uninfested controls.

Animals↗
PubMed2001

Bionomics of ticks collected from Sinai Peninsula: 2- abundance, attachment sites, and density estimators of ticks infesting Arabian camels.

Ten camels were examined monthly from January to December 1999, in Beer Lehfen North Sinai Gavernorate. A total of 5468 adult ticks of 6 species and subspecies of genus Hyalomma; H. dromedrii, H. ipmeltatum, H. a. excavatum, H. a. anatolicum, H. schulzei, and H. marginatum rufipes, in addition to 115 Hyalomma nymphs' species were collected. Of these, the first 4 types represented about 96.2% of the total collection. The infestation rate was higher during the period from March to November. The average monthly infestation rate was 22.78+/-3. The large number of the adult ticks were concentrated on tail, brisket, anus, and udder which totaled 68.2%. Attachment sites of males and females were not significantly correlated in most species. Nymphs were localized in few sites, whereas 91.6% of the total nymphs were attached to hump, neck, head (ear), and side. H. dromedarii, H. impeltatum, and H. a. excavatum were found on most of the body sites, tail, brisket, udder, and anus, totaling 79.9%. Males exceeded females in all sites, and were alone on neck and legs. Females were the only stage collected from udder. Both sex of H. a. anatolicum were collected from tail. H. schulzei and H. m. rufipes were concentrated in brisket, udder, anus, and tail.

Animal Diseases↗
PubMed2002

Control and eradication of chelonian tick infestations, with particular reference to vectors of heartwater.

Studies using the African tortoise tick (Amblyomma marmoreum) and leopard tortoises (Geochelone pardalis) demonstrated that cyfluthrin and permethrin were safe and efficacious acaricides for control of Amblyomma ticks on tortoises. A protocol was developed that successfully eradicated an A. sparsum infestation from a tortoise breeding facility in Florida. It involved treatment of all tortoises with a permethrin formulation, followed by treatment of the premises with a cyfluthrin formulation. Sentinel tortoises were later placed on the treated premises to establish successful tick eradication.

Animals↗
PubMed2001

Risk factors to tick infestations and their occurrence on horses in the state of São Paulo, Brazil.

From December 1998 to March 1999, 40 stud farms were studied in the state of São Paulo, Brazil. During visits to farms, horses reared under grazing conditions were examined for the presence of ticks. On each farm visit, horse pastures were closely inspected and a questionnaire was given to the farm supervisor with the purpose of gaining information about ecological and management variables (independent variables) that could be associated with the presence and infestation levels of ticks on the farm (dependent variables). Three tick species were found during the study. Anocentor nitens, Amblyomma cajennense and Boophilus microplus were present on horses from 38 (95%), 20 (50%) and four (10%) farms, respectively. All farms that had A. cajennense or B. microplus infestations also had A. nitens infestations. Only one of the four farms with B. microplus infestations on the horses also had A. cajennense infestations. Two farms had all horses free of ticks. There was a strong association between the presence of infestation by B. microplus on horses and the simultaneous use of a grazing area by cattle and horses (P = 0.000). There was no statistical association between any of the independent variables and the presence or infestation level of A. nitens on the horses (P > 0.20). The presence of A. cajennense was statistically associated with the presence of at least one mixed overgrowth pasture in the farm (P = 0.001). A mixed overgrowth pasture means the presence of undesired plants such as bushes and shrubs in the pasture. The presence of high levels of A. cajennense on horses was also associated with the presence of at least one mixed overgrowth pasture in the farm (P = 0.026). The regular use of acaricides was statistically associated with the presence of ticks on the horses (P < 0.05), making this procedure a result of the inefficacy of controlling ticks on the farms. The occurrence of human infestation by ticks was statistically associated with the presence of A. cajennense on the horses (P=0.000). The presence of at least one mixed overgrowth pasture on the farm was associated (P = 0.000) to either higher horse densities and to farms that did not mow all the pastures once a year, indicating that mowing all the pastures at least once a year can be considered a protective factor against the presence of mixed overgrowth pastures on the farm, and consequently, against the presence of A. cajennense on the horses.

Animal Husbandry↗
PubMed1991

[Seasonal dynamics of tick infestations in cattle (Ixodoidea) in cattle sold in the area of Yaoundé, Cameroon].

Among the tick species identified in Cameroon, eight were found in cattle in Yaoundé: Amblyomma variegatum, Boophilus annulatus, B. decoloratus, Haemaphysalis aciculifer, Hyalomma nitidum, Rhipicephalus longus, Rh. lunulatus, Rh. sulcatus. Three species, Hm. aciculifer, H. nitidum and Rh. lunulatus, were identified for the first time in Yaoundé. Rhipicephalus and Hyalomma were abundant during the rainy season. Boophilus was abundant throughout the year, with a maximum concentration at the end of the long dry season. Amblyomma, which was encountered in large quantities all year round, had a minimum infestation rate during the long rainy season. Only one female tick of Hm. aciculifer was collected.

Animals↗
PubMed1979

The basophil response in blood and bone marrow of tick-infested guinea pigs.

The concentrations of basophils in blood and bone marrow were monitored in guinea pigs subjected to primary and secondary infestations with larvae of Dermacentor andersoni. In these guinea pigs a significant increase of basophils was evident in peripheral blood. The response following the secondary infestation was more rapid and more intense than that following the primary infestation. Similar changes were also shown to occur in bone marrow. The possible significance of these responses in relation to acquired tick resistance in guinea pigs is discussed.

Animals↗