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Query: UMLS:C0851341 (infestation)
 10,121 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study examined the prevalence of Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner in host-seeking adult and nymphal Ixodes pacificus Cooley & Kohls and estimated the I. pacificus infestation and B. burgdorferi infection of rodent and avian hosts in the western Sierra Nevada foothills of northern California. Additionally, we identified species likely to participate in an enzootic cycle for B. burgdorferi in this yellow pine transition habitat. Evidence of infection with B. burgdorferi was identified in 7.3 and 5.4% of host-seeking I. pacificus adults and nymphs, respectively. Mean numbers of I. pacificus observed on rodents were 1.15 for Neotoma fuscipes Baird and 0.18 for Peromyscus spp. One of 104 ear punch tissues obtained from woodrats and none from 49 Peromyscus spp. yielded B. burgdorferi. A total of 291 collected birds representing 34 species had a mean of 0.27 I. pacificus per bird. The mean I. pacificus infestation of ground-dwelling birds was 2.5 ticks per bird. Forty-nine of 92 (53%) blood smears collected from birds were reactive to a B. burgdorferi specific antibody. This study presents the identification of a B. burgdorferi-like spirochete in birds in western North America. The tick burden and spirochete infection of birds suggests that birds may be involved in a local B. burgdorferi enzootic cycle and likely participate in the transport of ticks and spirochetes to other locations while rodents from this site do not appear to be major contributors.
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PMID:Ecology of Borrelia burgdorferi in ticks (Acari: Ixodidae), rodents, and birds in the Sierra Nevada foothills, Placer County, California. 1112 49

A total of 278 bats belonging to 16 species was examined for ticks from various sites in New Mexico from 1994 to 1998. Seven species of bats were parasitized by ticks: larvae of Ornithodoros kelleyi Cooley & Kohls, Ornithodoros rossi Kohls, Sonenshine & Clifford (Argasidae), or both. Both species of ticks are reported from New Mexico for the first time. Infestation prevalences for parasitized bats ranged from 2 to 25% on different host species for O. kelleyi and from 7 to 25% for O. rossi. The pallid bat, Antrozous pallidus, and the big brown bat. Eptesicus fuscus, were parasitized by both tick species. No distinct host specificity was noted for either tick species.
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PMID:Tick (Acari) infestations of bats in New Mexico. 1147 46

We compared the infestation by ixodid ticks of lizards, rodents, and birds collected simultaneously within areas representing common habitat types in Mendocino County, CA. Lizards were infested only by Ixodes pacificus Cooley and Kohls, birds by I. pacificus and Haemaphysalis leporispalustris (Packard), and rodents by I. pacificus, I. spinipalpis Hadwen and Nuttall, I. woodi Bishopp, Dermacentor occidentalis Marx, and D. variabilis (Say). Infestation by I. pacificus larvae and nymphs of lizards (Sceloporus occidentalis Baird and Girard; Elgaria spp.) and western gray squirrels (Sciurus griseus Ord) (means of 9-35 larvae and 5-6 nymphs per animal) was several times greater than for Neotoma fuscipes Baird woodrats, Peromyscus spp. mice, and birds (means of 0.9-3.5 larvae and 0-0.3 nymphs). Overall, Borrelia-refractory lizards accounted for 84% of I. pacificus larvae and 91% of nymphs collected from animals in dense woodlands. Bird species frequently utilizing tick-questing substrates such as leaf litter (guild I birds) were more heavily infested by I. pacificus subadults (5.2 larvae and 1.0 nymphs per bird) than guild IV birds with minimal perceived contact with tick-questing substrates (0.08 larvae and 0.06 nymphs per bird). Notably, guild I birds carried similar larval loads and at least 20-fold higher nymphal loads relative to woodrats and mice. Only guild IV birds carried as few I. pacificus nymphs as did these rodents. The ratios of larvae to nymphs suggest that, relative to birds, lizards, and squirrels (infested by 1.3-6.0 larvae per nymph), nocturnally active ground-dwelling rodents such as woodrats and mice are underutilized by the nymphal stage (69 to >100 larvae per nymph). The western gray squirrel and guild I-II birds (e.g., the dark-eyed junco, Junco hyemalis [L.]) were the only potential reservoirs of Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt, and Brenner (the causative agent of Lyme disease in North America) that were frequently infested with both I. pacificus larvae and nymphs and commonly utilized dense woodland habitats.
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PMID:The roles of birds, lizards, and rodents as hosts for the western black-legged tick Ixodes pacificus. 1570 49

Birds from 45 species were sampled during three spring seasons from an isolated canyon on the Sutter Buttes in California for the presence of subadult stages of Ixodes pacificus Cooley & Kohls, and for infection with Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner. These birds were found to have an infestation prevalence of 45%, a density of 1.7 ticks per bird, and an intensity of 3.8 ticks per infested bird. There was a significant difference in the I. pacificus infestations between canopy and ground-dwelling birds. Birds also demonstrated an overall infection with B. burgdorferi of 6.4% with significant difference between bird species. Amplification and subsequent sequencing of the 23s-5s rRNA intergenic spacer region of the Borrelia genome from one bird, a hermit thrush, Catharus guttatus (Nuttall), showed that the infection in this bird was caused by B. burgdorferi sensu stricto; the first such finding in a bird from the far west. Our results suggest that birds play a role in the distribution and maintenance of I. pacificus, and possibly of B. burgdoferi, at the Sutter Buttes, CA.
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PMID:An avian contribution to the presence of Ixodes pacificus (Acari: Ixodidae) and Borrelia burgdorferi on the Sutter Buttes of California. 1661 23

A survey of wild rodents was performed in the Morro Bay area of central coastal California to determine serological and polymerase chain reaction (PCR) prevalence of Anaplasma phagocytophilum Dumler, Barbet, Bekker, Dasch, Palmer, Ray, Rikihisa, and Rurangirwa, Borrelia burgdorferi Johnson, Schmidt, Hyde, Steigerwalt, and Brenner, Francisella tularensis McCoy, and Yersinia pestis Yersin; to describe the ectoparasitic fauna on important vector-borne disease hosts; and to determine whether pathogen exposure was associated with infestation by ectoparasites. We trapped 411 rodents from 10 species in 2004 and 2005. Anaplasma phagocytophilum exposure was detected in 11% of all wild rodents tested, with seropositive animals in eight species. Anaplasma phagocytophilum DNA was detected by PCR amplification in Neotoma fuscipes Baird and Reithrodontomys megalotis Baird (0.6% of all rodents). Yersinia spp. exposure was identified in 3.2% of all rodents tested, with highest detected exposure in peridomestic rodents, Mus musculus L. (20%), and Rattus rattus L. (50%). No individuals tested positive for the Y. pestis pla gene by PCR. In total, 338 fleas were identified from each of 10 rodent species examined. The most abundant flea was Malareus telchinus Rothschild. Relative density of flea infestation was highest on Spermophilus beecheyi Richardson and Microtus californicus Peale. Ticks recovered from trapped animals included Ixodes angustus Neumann, Ixodes pacificus Cooley & Kohls, Ixodes spinipalpis Hadwen & Nuttall, and Dermacentor occidentalis Marx. Given the moderate climate and diversity of rodents and arthropods in the Morro Bay area, ongoing investigation of this region will be helpful in understanding disease maintenance cycles.
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PMID:Ectoparasite diversity and exposure to vector-borne disease agents in wild rodents in central coastal California. 1742 5

Lyme disease is the most commonly reported vector-borne disease in the United States, with the majority of cases occurring in the Northeast. It has now been three decades since the etiological agent of the disease in North America, the spirochete Borrelia burgdorferi, and its primary North American vectors, the ticks Ixodes scapularis Say and I. pacificus Cooley & Kohls, were identified. Great strides have been made in our understanding of the ecology of the vectors and disease agent, and this knowledge has been used to design a wide range of prevention and control strategies. However, despite these advances, the number of Lyme disease cases have steadily increased. In this article, we assess potential reasons for the continued lack of success in prevention and control of Lyme disease in the northeastern United States, and identify conceptual areas where additional knowledge could be used to improve Lyme disease prevention and control strategies. Some of these areas include: 1) identifying critical host infestation rates required to maintain enzootic transmission of B. burgdorferi, 2) understanding how habitat diversity and forest fragmentation impacts acarological risk of exposure to B. burgdorferi and the ability of interventions to reduce risk, 3) quantifying the epidemiological outcomes of interventions focusing on ticks or vertebrate reservoirs, and 4) refining knowledge of how human behavior influences Lyme disease risk and identifying barriers to the adoption of personal protective measures and environmental tick management.
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PMID:What do we need to know about disease ecology to prevent Lyme disease in the northeastern United States? 2230 66