50 research outputs found

    Avian Hosts for West Nile Virus in St. Tammany Parish, Louisiana, 2002

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    West Nile virus (WNV) infections in free-ranging birds were studied in Slidell, St. Tammany Parish, Louisiana, after a human encephalitis outbreak peaked there in July 2002. Seroprevalence in resident, free-ranging wild birds in one suburban site was 25% and 24% in August and October, respectively, indicating that most transmission had ceased by early August. Mortality rates, seroprevalence rates, host competence, and crude population estimates were used in mathematical models to predict actual infection rates, population impacts, and importance as amplifying hosts for several common passerine birds. Northern cardinal (Cardinalis cardinalis) and house sparrow (Passer domesticus) were the principal amplifying hosts, but blue jay (Cyanocitta cristata) and northern mockingbird (Mimus polyglottos) also contributed. The blue jay population was reduced by an estimated 47%. A variety of passerine bird species combined to play an important role as amplifying hosts in the WNV transmission cycle

    Experimental Inoculation of House Sparrows (\u3ci\u3ePasser domesticus\u3c/i\u3e) with Buggy Creek Virus

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    We performed experimental inoculations of house sparrows (Passer domesticus) with Buggy Creek virus (BCRV), a poorly known alphavirus (Togaviridae) vectored primarily by the swallow bug (Hemiptera: Cimicidae: Oeciacus vicarius) that is an ectoparasite of the cliff swallow (Petrochelidon pyrrhonota) and house sparrow. Viremias were detected by plaque assay in two of six birds on days 1–3 postinoculation; viremia was highest on day 2. Viral RNA was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) in blood of six of 12 birds ranging from day 1 to day 15 postinoculation. Infectious BCRV was detected in nasopharyngeal swab samples from two birds by plaque assay. Three control birds that were housed with viremic individuals showed evidence of BCRV RNA in blood (by RT-PCR), suggesting possible bird-to-bird transmission of this virus. Viral RNA also was detected by RT-PCR in brain and skin tissue of six birds on necropsy at the end of the 16-day experiment. Introduced house sparrows are apparently a competent amplifying host for BCRV, and their presence year-round at cliff swallow colonies may facilitate persistence of the virus locally, especially when cliff swallows abandon a site temporarily. The findings that BCRV can be shed orally, that it persists in bird skin, and that control birds could apparently be infected by conspecifics suggest that this virus may be transmitted from bird to bird in the crowded conditions of many cliff swallow colonies

    Experimental Inoculation of House Sparrows (\u3ci\u3ePasser domesticus\u3c/i\u3e) with Buggy Creek Virus

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    We performed experimental inoculations of house sparrows (Passer domesticus) with Buggy Creek virus (BCRV), a poorly known alphavirus (Togaviridae) vectored primarily by the swallow bug (Hemiptera: Cimicidae: Oeciacus vicarius) that is an ectoparasite of the cliff swallow (Petrochelidon pyrrhonota) and house sparrow. Viremias were detected by plaque assay in two of six birds on days 1–3 postinoculation; viremia was highest on day 2. Viral RNA was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) in blood of six of 12 birds ranging from day 1 to day 15 postinoculation. Infectious BCRV was detected in nasopharyngeal swab samples from two birds by plaque assay. Three control birds that were housed with viremic individuals showed evidence of BCRV RNA in blood (by RT-PCR), suggesting possible bird-to-bird transmission of this virus. Viral RNA also was detected by RT-PCR in brain and skin tissue of six birds on necropsy at the end of the 16-day experiment. Introduced house sparrows are apparently a competent amplifying host for BCRV, and their presence year-round at cliff swallow colonies may facilitate persistence of the virus locally, especially when cliff swallows abandon a site temporarily. The findings that BCRV can be shed orally, that it persists in bird skin, and that control birds could apparently be infected by conspecifics suggest that this virus may be transmitted from bird to bird in the crowded conditions of many cliff swallow colonies

    Bourbon Virus in Wild and Domestic Animals, Missouri, USA, 2012–2013

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    Bourbon virus (BRBV) was first isolated from a febrile patient with a history of tick bites in Bourbon County, Kansas, USA; the patient later died from severe illness in 2014 (1). Several additional human BRBV infections were reported subsequently from the midwestern and southern United States (2). BRBV belongs to the family Orthomyxoviridae, genus Thogotovirus, which is distributed worldwide and includes Araguari, Aransas Bay, Dhori, Jos, Thogoto, and Upolu viruses (1,3). Thogoto and Dhori viruses have been associated with human disease (4–6). Viruses within the genus Thogotovirus have been associated with hard or soft ticks (7). Recent studies suggest that the lone star tick (Amblyomma americanum) is involved with BRBV transmission (2,3,8). These ticks feed primarily on mammals, which might play a role in BRBV ecolog

    Rapid West Nile Virus Antigen Detection

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    We compared the VecTest WNV antigen assay with standard methods of West Nile virus (WNV) detection in swabs from American Crows (Corvus brachyrhynchos) and House Sparrows (Passer domesticus). The VecTest detected WNV more frequently than the plaque assay and was comparable to a TaqMan reverse transcription–polymerase chain reaction

    Exposure of Egyptian Rousette Bats (\u3ci\u3eRousettus aegyptiacus\u3c/i\u3e) and a Little Free-Tailed Bat (\u3ci\u3eChaerephon pumilus\u3c/i\u3e) to Alphaviruses in Uganda

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    The reservoir for zoonotic o’nyong-nyong virus (ONNV) has remained unknown since this virus was first recognized in Uganda in 1959. Building on existing evidence for mosquito bloodfeeding on various frugivorous bat species in Uganda, and seroprevalence for arboviruses among bats in Uganda, we sought to assess if serum samples collected from bats in Uganda demonstrated evidence of exposure to ONNV or the closely related zoonotic chikungunya virus (CHIKV). In total, 652 serum samples collected from six bat species were tested by plaque reduction neutralization test (PRNT) for neutralizing antibodies against ONNV and CHIKV. Forty out of 303 (13.2%) Egyptian rousettes from Maramagambo Forest and 1/13 (8%) little free-tailed bats from Banga Nakiwogo, Entebbe contained neutralizing antibodies against ONNV. In addition, 2/303 (0.7%) of these Egyptian rousettes contained neutralizing antibodies to CHIKV, and 8/303 (2.6%) contained neutralizing antibodies that were nonspecifically reactive to alphaviruses. These data support the interepidemic circulation of ONNV and CHIKV in Uganda, although Egyptian rousette bats are unlikely to serve as reservoirs for these viruses given the inconsistent occurrence of antibody-positive bats

    Reinterpretation of LHC Results for New Physics: Status and recommendations after Run 2

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    We report on the status of efforts to improve the reinterpretation of searches and measurements at the LHC in terms of models for new physics, in the context of the LHC Reinterpretation Forum. We detail current experimental offerings in direct searches for new particles, measurements, technical implementations and Open Data, and provide a set of recommendations for further improving the presentation of LHC results in order to better enable reinterpretation in the future. We also provide a brief description of existing software reinterpretation frameworks and recent global analyses of new physics that make use of the current data

    Declining Mortality in American Crow (\u3ci\u3eCorvus Brachyrhynchos\u3c/i\u3e) Following Natural West Nile Virus Infection

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    The American crow (Corvus brachyrhynchos) is known to suffer 100% mortality from infection with the New York 1999 strain of West Nile virus (WNV). Following the initial detection of WNV in North America in 1999, we measured prevalence of WNV-reactive antibodies (‘‘seroprevalence”) in free-ranging American and fish crows (Corvus ossifragus) of central New Jersey after each transmission season through 2005. In 2002, seroprevalence in American crow juveniles increased to 14% from the 5% of the previous year, potentially indicating increased survival in this species. Using the annual seroprevalence measurements and the number of human West Nile neuroinvasive disease cases as a surrogate for WNV transmission intensity, we developed a model to estimate the annual WNV-associated mortality rates among both of these crow species. Our model supports the hypothesis that mortality is changing over time; the WNV-associated mortality rate declined over time by 1.5% for American crow and by 1.1% for fish crow. The probability that the trend in mortality was negative was 90% for the American crow and 60% for the fish crow
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