583 research outputs found

    Ixodes brunneus (Acari: Ixodidae) from Two Bird Hosts: A New Michigan Tick

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    The tick Ixodes brunneus Koch (Acari: Ixodidae) is reported for the first time in Michigan from two bird hosts at two locations in the lower peninsula. All stages of this tick exclusively feed on birds, and are primarily known from the southern U.S., although abundant records occur from northern states. The role of this species as a vector of pathogens is discussed

    Occurrence of Ticks (Acari: Ixodidae) on Birds in Northwestern Lower Michigan, 2011-2019

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    Abstract Monitoring tick infestation of wildlife provides baseline tick occurrence data that may have human or animal health implications. We collected 312 ticks of four species from 5,122 birds of 93 species while monitoring bird migration during 15 fall and spring seasons between 2011 and 2019 in the northern Lower Peninsula of Michigan. Twenty-seven of 93 bird species hosted ticks with an overall prevalence (=at least one tick) of 3.6% (185/5,122). Median burden was one tick/per infested bird with a range of 1-16 ticks per infested bird. Tick species collected were primarily Haemaphysalis leporispalustris (Packard) and Ixodes scapularis Say, with smaller numbers of Ixodes dentatus Marx and a single Ixodes brunneus (Koch). The prevalence of avian infestations by I. scapularis increased over the eight-year study period (P = 0.046) to a high of over 4.6% infestation by I. scapularis in 2019. Based on the migratory status of birds, our data suggest that birds transported ticks to our site from northern or southern areas. Additionally, based on bird recapture data during stopover periods at our site, we detected new tick infestations in 27 of 437 birds that had ticks removed on initial capture. These reinfestations potentially reflect bird’s local acquisition of ticks, such as I. scapularis. This indicates that I. scapularis is becoming established in the region, which appears to be on the leading edge of this tick’s expanding range in the Lower Peninsula of Michigan. Birds may be contributing to the establishment by contributing and possibly introducing and maintaining the ticks. Birds may be transporting ticks and seeding them elsewhere

    Quantitative synthesis of the role of birds in carrying ticks and tick-borne pathogens in North America

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    Birds play a central role in the ecology of tick-borne pathogens. They expand tick populations and pathogens across vast distances and serve as reservoirs that maintain and amplify transmission locally. Research into the role of birds for supporting ticks and tick-borne pathogens has largely been descriptive and focused in small areas. To expand inference beyond these studies, we conducted a quantitative review at the scale of North America to identify avian life history correlates of tick infestation and pathogen prevalence, calculate species-level indices of importance for carrying ticks, and identify research gaps limiting understanding of tick-borne pathogen transmission. Across studies, 78 of 162 bird species harbored ticks, yielding an infestation prevalence of 1981 of 38,929 birds (5.1�%). Avian foraging and migratory strategies interacted to influence infestation. Ground-foraging species, especially non-migratory ground foragers, were disproportionately likely to have high prevalence and intensity of tick infestation. Studies largely focused on Borrelia burgdorferi, the agent of Lyme disease, and non-migratory ground foragers were especially likely to carry B. burgdorferi-infected ticks, a finding that highlights the potential importance of resident birds in local pathogen transmission. Based on infestation indices, all 'super-carrier' bird species were passerines. Vast interior areas of North America, many bird and tick species, and most tick-borne pathogens, remain understudied, and research is needed to address these gaps. More studies are needed that quantify tick host preferences, host competence, and spatiotemporal variation in pathogen prevalence and vector and host abundance. This information is crucial for predicting pathogen transmission dynamics under future global change.Peer reviewedNatural Resource Ecology and ManagementEntomology and Plant Patholog

    Coccidian Parasites and Conservation Implications for the Endangered Whooping Crane (Grus americana)

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    While the population of endangered whooping cranes (Grus americana) has grown from 15 individuals in 1941 to an estimated 304 birds today, the population growth is not sufficient to support a down-listing of the species to threatened status. The degree to which disease may be limiting the population growth of whooping cranes is unknown. One disease of potential concern is caused by two crane-associated Eimeria species: Eimeria gruis and E. reichenowi. Unlike most species of Eimeria, which are localized to the intestinal tract, these crane-associated species may multiply systemically and cause a potentially fatal disease. Using a non-invasive sampling approach, we assessed the prevalence and phenology of Eimeria oocysts in whooping crane fecal samples collected across two winter seasons (November 2012–April 2014) at the Aransas National Wildlife Refuge along the Texas Gulf coast. We also compared the ability of microscopy and PCR to detect Eimeria in fecal samples. Across both years, 26.5% (n = 328) of fecal samples were positive for Eimeria based on microscopy. Although the sensitivity of PCR for detecting Eimeria infections seemed to be less than that of microscopy in the first year of the study (8.9% vs. 29.3%, respectively), an improved DNA extraction protocol resulted in increased sensitivity of PCR relative to microscopy in the second year of the study (27.6% and 20.8%, respectively). The proportion of positive samples did not vary significantly between years or among sampling sites. The proportion of Eimeria positive fecal samples varied with date of collection, but there was no consistent pattern of parasite shedding between the two years. We demonstrate that non-invasive fecal collections combined with PCR and DNA sequencing techniques provides a useful tool for monitoring Eimeria infection in cranes. Understanding the epidemiology of coccidiosis is important for management efforts to increase population growth of the endangered whooping crane.The open access fee for this work was funded through the Texas A&M University Open Access to Knowledge (OAK) Fund

    Associations of passerine birds, rabbits, and ticks with \u3cem\u3eBorrelia miyamotoi and Borrelia andersonii\u3c/em\u3e in Michigan, U.S.A.

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    Background Wild birds contribute to maintenance and dissemination of vectors and microbes, including those that impact human, domestic animal, and wildlife health. Here we elucidate roles of wild passerine birds, eastern cottontail rabbits (Sylvilagus floridanus), and Ixodes dentatus ticks in enzootic cycles of two spirochetes, Borrelia miyamotoi and B. andersonii in a region of Michigan where the zoonotic pathogen B. burgdorferi co-circulates. Methods Over a four-year period, wild birds (n = 19,631) and rabbits (n = 20) were inspected for tick presence and ear tissue was obtained from rabbits. Samples were tested for Borrelia spirochetes using nested PCR of the 16S-23S rRNA intergenic spacer region (IGS) and bidirectional DNA sequencing. Natural xenodiagnosis was used to implicate wildlife reservoirs. Results Ixodes dentatus, a tick that specializes on birds and rabbits and rarely bites humans, was the most common tick found, comprising 86.5% of the 12,432 ticks collected in the study. The relapsing fever group spirochete B. miyamotoi was documented for the first time in ticks removed from wild birds (0.7% minimum infection prevalence; MIP, in I. dentatus), and included two IGS strains. The majority of B. miyamotoi-positive ticks were removed from Northern Cardinals (Cardinalis cardinalis). Borrelia andersonii infected ticks removed from birds (1.6% MIP), ticks removed from rabbits (5.3% MIP), and rabbit ear biopsies (5%) comprised twelve novel IGS strains. Six species of wild birds were implicated as reservoirs for B. andersonii. Frequency of I. dentatus larval and nymphal co-feeding on birds was ten times greater than expected by chance. The relatively well-studied ecology of I. scapularis and the Lyme disease pathogen provides a context for understanding how the phenology of bird ticks may impact B. miyamotoi and B. andersonii prevalence and host associations. Conclusions Given the current invasion of I. scapularis, a human biting species that serves as a bridge vector for Borrelia spirochetes, human exposure to B. miyamotoi and B. andersonii in this region may increase. The presence of these spirochetes underscores the ecological complexity within which Borrelia organisms are maintained and the need for diagnostic tests to differentiate among these organisms

    Are routinely collected NHS administrative records suitable for endpoint identification in clinical trials? Evidence from the West of Scotland coronary prevention study

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    Background: Routinely collected electronic patient records are already widely used in epidemiological research. In this work we investigated the potential for using them to identify endpoints in clinical trials.<p></p> Methods: The events recorded in the West of Scotland Coronary Prevention Study (WOSCOPS), a large clinical trial of pravastatin in middle-aged hypercholesterolaemic men in the 1990s, were compared with those in the record-linked deaths and hospitalisations records routinely collected in Scotland.<p></p> Results: We matched 99% of fatal study events by date. We showed excellent matching (97%) of the causes of fatal endpoint events and good matching (.80% for first events) of the causes of nonfatal endpoint events with a slightly lower rate of mismatching of record linkage than study events (19% of first study myocardial infarctions (MI) and 4% of first record linkage MIs not matched as MI). We also investigated the matching of non-endpoint events and showed a good level of matching, with .78% of first stroke/TIA events being matched as stroke/TIA. The primary reasons for mismatches were record linkage data recording readmissions for procedures or previous events, differences between the diagnoses in the routinely collected data and the conclusions of the clinical trial expert adjudication committee, events occurring outside Scotland and therefore being missed by record linkage data, miscoding of cardiac events in hospitalisations data as ‘unspecified chest pain’, some general miscoding in the record linkage data and some record linkage errors.<p></p> Conclusions: We conclude that routinely collected data could be used for recording cardiovascular endpoints in clinical trials and would give very similar results to rigorously collected clinical trial data, in countries with unified health systems such as Scotland. The endpoint types would need to be carefully thought through and an expert endpoint adjudication committee should be involved.<p></p&gt

    Effect of short-term weight loss on mental stress-induced cardiovascular and pro-inflammatory responses in women

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    Epidemiologic evidence links psychosocial stress with obesity but experimental studies examining the mechanisms that mediates the effect of stress on adiposity are scarce. The aim of this study was to investigate whether changes in adiposity following minimal weight loss affect heightened stress responses in women, and examine the role of the adipokine leptin in driving inflammatory responses. Twenty-three overweight or obese, but otherwise healthy, women (M age ¼ 30.41 ± 8.0 years; BMI ¼ 31.9 ± 4.1 kg/m2 ) completed standardized acute mental stress before and after a 9-week calorie restriction program designed to modify adiposity levels. Cardiovascular (blood pressure and heart rate) and inflammatory cytokines (leptin and interleukin-6; IL-6) responses to mental stress were assessed several times between baseline and a 45-min post-stress recovery period. There were modest changes in adiposity measures while the adipokine leptin was markedly reduced (27%) after the intervention. Blood pressure reactivity was attenuated (3.38 ± 1.39 mmHg) and heart rate recovery was improved (2.07 ± 0.96 Bpm) after weight loss. Blood pressure responses were inversely associated with changes in waist to hip ratio post intervention. Decreased levels of circulating leptin following weight loss were inversely associated with the IL-6 inflammatory response to stress (r ¼ 0.47). We offered preliminary evidence suggesting that modest changes in adiposity following a brief caloric restriction program may yield beneficial effect on cardiovascular stress responses. In addition, reductions in basal leptin activity might be important in blunting pro-inflammatory responses. Large randomized trials of the effect of adiposity on autonomic responses are thus warranted

    Programa piloto de ciencia ciudadana en México para vigilancia pasiva de triatominos y concientizar sobre la enfermedad de Chagas

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    Objective. To generate data about Chagas disease vectors through passive surveillance and inform the public using social media and community science. Materials and methods. We used social media to inform, raise awareness and to promote the public to report their triatomine encounters. We received pictures and specimens collected to be tested for Trypanosoma cruzi and to identify recent bloodmeal source through PCR. Results. Community scientists reported 44 triatomines from 15 states in Mexico and one triatomine from Nicaragua, including 9 species with Triatoma dimidiata sensu lato and T. gerstaeckeri being the most common. We received 12 collected specimens and T. cruzi was detected in 8 (67%) of the discrete typing unit TcI. We identified recent bloodmeal source in 6 triatomines including: human (Homo sapiens), dog (Canis lupus familiaris), wood rat (Neotoma sp.), dove (Columbidae) and amphibius (Bufonidae). Conclusion. The use of community science can be a complementary method to generate information about the ecology and epidemiology of Chagas disease vectors.Objetivo. Generar datos sobre vectores de la enfermedad de Chagas (EC) mediante vigilancia pasiva e informar a la población mediante redes sociales y ciencia ciudadana. Material y métodos. Utilizando redes sociales informamos, concientizamos y alentamos al público a reportarnos sus encuentros con triatominos. Recibimos reportes fotográficos y especímenes colectados a los que analizamos para detectar infección por Trypanosoma cruzi e identificar la fuente reciente de alimentación mediante PCR. Resultados. Nos reportaron 44 triatominos de 15 estados en México y uno de Nicaragua, incluyendo 9 especies siendo Triatoma dimidiata sensu lato y T. gerstaeckeri las más comunes. Recibimos 12 especímenes colectados y encontramos T. cruzi en 8 (67%) de la unidad taxonómica discreta TcI. Identificamos fuente reciente de alimentación en 6 triatominos incluyendo: humano (Homo sapiens), perro (Canis lupus familiaris), rata de campo (Neotoma sp.), paloma (Columbidae) y anfibio (Bufonidae). Conclusión. Ciencia ciudadana puede ser un método complementario para generar información sobre ecología y epidemiología de EC

    Rapid detection of human blood in triatomines (kissing bugs) utilizing a lateral flow immunochromatographic assay - A pilot study

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    BACKGROUND DNA- and proteomics-based techniques are currently used to identify a triatomine human blood meal. These methods are time consuming, require access to laboratories with sophisticated equipment, and trained personnel. OBJECTIVES We tested a rapid and specific immunochromatographic assay (that detects human blood in forensic samples) to determine if human blood was present in triatomines and their fecal excreta. METHODS We fed Triatoma rubida human blood (positive control) or mouse blood (negative control) and performed the assay on the abdominal contents and fecal excreta. Triatomine field specimens collected in and around human habitations and excreta were also tested. FINDINGS The assay was positive in triatomines fed human blood (N = 5/5) and fecal excreta from bugs known to have ingested human blood (N = 5/5). Bugs feeding on mice (N = 15/15) and their fecal excreta (N = 8/8) were negative for human blood. Human blood was detected in 47% (N = 23/49) triatomines, representing six different species, collected in the field. MAIN CONCLUSIONS The pilot study shows that this rapid and specific test may have applications in triatomine research. Further study is needed to determine the sensitivity of this assay compared to other well-established techniques, such as DNA- and proteomics-based methodologies and the assay's application in the field.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
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