316 research outputs found

    Use of the X-Band Radar to Support the Detection of In-Flight Icing Hazards by the NASA Icing Remote Sensing System

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    The Alliance Icing Research Study-II (AIRS-II) field program was conducted near Montreal, Canada during the winter of 2003. The NASA Icing Remote Detection System (NIRSS) was deployed to detect in-flight icing hazards and consisted of a vertically pointing multichannel radiometer, a ceilometer and an x-band cloud radar. The radiometer was used to derive atmospheric temperature soundings and integrated liquid water, while the ceilometer and radar were used only to define cloud boundaries. The purpose of this study is to show that the radar reflectivity profiles from AIRS-II case studies could be used to provide a qualitative icing hazard

    Longitudinal Analysis of Antibody Responses to Trachoma Antigens Before and After Mass Drug Administration.

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    Blinding trachoma, caused by the bacteria Chlamydia trachomatis, is a neglected tropical disease targeted for elimination by 2020. A major component of the elimination strategy is mass drug administration (MDA) with azithromycin. Currently, program decisions are made based on clinical signs of ocular infection, but we have been investigating the use of antibody responses for post-MDA surveillance. In a previous study, IgG responses were detected in children lacking clinical evidence of trachoma, suggesting that IgG responses represented historical infection. To explore the utility of serology for program evaluation, we compared IgG and IgA responses to trachoma antigens and examined changes in IgG and IgA post-drug treatment. Dried blood spots and ocular swabs were collected with parental consent from 264 1-6 year olds in a single village of Kongwa District, central Tanzania. Each child also received an ocular exam for detection of clinical signs of trachoma. MDA was given, and six months later an additional blood spot was taken from these same children. Ocular swabs were analyzed for C. trachomatis DNA and antibody responses for IgA and total IgG were measured in dried bloods spots. Baseline antibody responses showed an increase in antibody levels with age. By age 6, the percentage positive for IgG (96.0%) was much higher than for IgA (74.2%). Antibody responses to trachoma antigens declined significantly six months after drug treatment for most age groups. The percentage decrease in IgA response was much greater than for IgG. However, no instances of seroreversion were observed. Data presented here suggest that focusing on concordant antibody responses in children will provide the best serological surveillance strategy for evaluation of trachoma control programs

    Epidemic spread of adenovirus type 4-associated acute respiratory disease between U.S. Army installations.

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    A large outbreak of adenovirus type 4-associated acute respiratory disease (ARD) occurred at Fort Jackson, South Carolina, in 1997. A laboratory-based ARD surveillance program was initiated at Fort Gordon, Georgia, where advanced individual training was heavily populated with Fort Jackson soldiers. Adenovirus type 4 was isolated from 50% of 147 trainees hospitalized with ARD. Most (88%) introduced cases were in trainees from Fort Jackson

    Disease epidemic and a marine heat wave are associated with the continental-scale collapse of a pivotal predator (Pycnopodia helianthoides)

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    Multihost infectious disease outbreaks have endangered wildlife, causing extinction of frogs and endemic birds, and widespread declines of bats, corals, and abalone. Since 2013, a sea star wasting disease has affected > 20 sea star species from Mexico to Alaska. The common, predatory sunflower star (Pycnopodia helianthoides), shown to be highly susceptible to sea star wasting disease, has been extirpated across most of its range. Diver surveys conducted in shallow nearshore waters (n = 10,956; 2006-2017) from California to Alaska and deep offshore (55 to 1280 m) trawl surveys from California to Washington (n = 8968; 2004-2016) reveal 80 to 100% declines across a similar to 3000-km range. Furthermore, timing of peak declines in nearshore waters coincided with anomalously warm sea surface temperatures. The rapid, widespread decline of this pivotal subtidal predator threatens its persistence and may have large ecosystem-level consequences

    Prevalence of Trichomonas vaginalis and Coinfection with Chlamydia trachomatis and Neisseria gonorrhoeae in the United States as Determined by the Aptima Trichomonas vaginalis Nucleic Acid Amplification Assay

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    Our aim was to determine Trichomonas vaginalis prevalence using the Aptima Trichomonas vaginalis assay (ATV; Gen-Probe) and the prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae coinfections in U.S. women undergoing screening for C. trachomatis/N. gonorrhoeae. Discarded urogenital samples from 7,593 women (18 to 89 years old) undergoing C. trachomatis/N. gonorrhoeae screening using the Aptima Combo 2 assay (Gen-Probe) in various clinical settings were tested with ATV. Overall, T. vaginalis, C. trachomatis, and N. gonorrhoeae prevalences were 8.7%, 6.7%, and 1.7%, respectively. T. vaginalis was more prevalent than C. trachomatis or N. gonorrhoeae in all age groups except the 18- to 19-year-old group. The highest T. vaginalis prevalence was in women ≥40 years old (>11%), while the highest C. trachomatis prevalence (9.2%) and N. gonorrhoeae prevalence (2.2%) were in women C. trachomatis/T. vaginalis, 0.61% for C. trachomatis/N. gonorrhoeae and N. gonorrhoeae/T. vaginalis, and 0.24% for C. trachomatis/N. gonorrhoeae/T. vaginalis and highest in women T. vaginalis prevalence differed by race/ethnicity, with the highest prevalence in black women (20.2%). T. vaginalis prevalence ranged from 5.4% in family planning clinics to 22.3% in jails. Multivariate analysis determined that ages of ≥40 years, black race, and patient locations were significantly associated with T. vaginalis infection. T. vaginalis is the most common sexually transmitted infection (STI) in women of >40 years, while C. trachomatis and N. gonorrhoeae prevalence is lowest in that age group. Higher T. vaginalis prevalence in women of >40 years is probably attributed to the reason for testing, i.e., symptomatic status versus routine screening in younger women. Coinfections were relatively low. High T. vaginalis prevalence in all age groups suggests that women screened for C. trachomatis/N. gonorrhoeae, whether asymptomatic or symptomatic, should be screened for T. vaginalis

    Home-based chlamydia testing of young people attending a music festival - who will pee and post?

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    <p>Abstract</p> <p>Background</p> <p>Chlamydia is most common among young people, but only a small proportion of Australian young people are tested annually. Home-based chlamydia testing has been piloted in several countries to increase testing rates, but uptake has been low. We aimed to identify predictors of uptake of home-based chlamydia testing to inform future testing programs.</p> <p>Methods</p> <p>We offered home-based chlamydia testing kits to participants in a sexual behaviour cross-sectional survey conducted at a music festival in Melbourne, Australia. Those who consented received a testing kit and were asked to return their urine or vaginal swab sample via post.</p> <p>Results</p> <p>Nine hundred and two sexually active music festival attendees aged 16-29 completed the survey; 313 (35%) opted to receive chlamydia testing kits, and 67 of 313 (21%) returned a specimen for testing. One participant was infected with chlamydia (1% prevalence). Independent predictors of consenting to receive a testing kit included older age, knowing that chlamydia can make women infertile, reporting more than three lifetime sexual partners and inconsistent condom use. Independent predictors of returning a sample to the laboratory included knowing that chlamydia can be asymptomatic, not having had an STI test in the past six months and not living with parents.</p> <p>Conclusions</p> <p>A low proportion of participants returned their chlamydia test, suggesting that this model is not ideal for reaching young people. Home-based chlamydia testing is most attractive to those who report engaging in sexual risk behaviours and are aware of the often asymptomatic nature and potential sequelae of chlamydia infection.</p

    Computed Tomography of the Mandibles of a Stranded Offshore Killer Whale (Orcinus orca)

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    A mature, adult female, offshore killer whale (Orcinus orca) was stranded deceased in Portage Bay, Alaska, in October 2015. Full necropsy examination with histopathology was performed. Consistent with previous studies of offshore killer whales, and thought to be a result of their unique elasmobranch diet, all the teeth were significantly abraded and almost flush with the gingival margin. Age was estimated at 30–35 years based on annuli and growth arrest lines in a remaining tooth. The dentate portion of the mandibles were excised en bloc and frozen until imaging could be completed. Radiography and computed tomography revealed lesions consistent with severe abrasion, pulp exposure and evidence of endodontic and/or periodontal disease in nine of the 15 mandibular teeth present (60.0%). Only five (33.3%) teeth were suspected to have been vital at the time of death based on imaging. Lesions were more severe rostrally, with the caudal teeth less affected. Autolysis precluded gingival histopathology and no teeth were analyzed histologically. Necropsy examination revealed a likely multifactorial cause of death, with most significant lesions including the severe chronic periodontal/endodontic disease with abrasion, inanition and emaciation with possible cardiovascular disease. This case highlights the importance of imaging in evaluating periodontal and endodontic status, especially post mortem when other tissues are no longer available, and demonstrates that periodontal and endodontic disease occur naturally in this species and can be a significant cause of morbidity in mature free-ranging killer whales of the offshore ecotype

    Young people's views on the potential use of telemedicine consultations for sexual health: results of a national survey

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    <p>Abstract</p> <p>Background</p> <p>Young people are disproportionately affected by sexually transmissible infections in Australia but face barriers to accessing sexual health services, including concerns over confidentiality and, for some, geographic remoteness. A possible innovation to increase access to services is the use of telemedicine.</p> <p>Methods</p> <p>Young people's (aged 16-24) pre-use views on telephone and webcam consultations for sexual health were investigated through a widely-advertised national online survey in Australia. Descriptive statistics were used to describe the study sample and chi-square, Mann-Whitney U test, or t-tests were used to assess associations. Multinomial logistic regression was used to explore the association between the three-level outcome variable (first preference in person, telephone or webcam, and demographic and behavioural variables); odds ratios and 95%CI were calculated using in person as the reference category. Free text responses were analysed thematically.</p> <p>Results</p> <p>A total of 662 people completed the questionnaire. Overall, 85% of the sample indicated they would be willing to have an in-person consultation with a doctor, 63% a telephone consultation, and 29% a webcam consultation. Men, respondents with same-sex partners, and respondents reporting three or more partners in the previous year were more willing to have a webcam consultation. Imagining they lived 20 minutes from a doctor, 83% of respondents reported that their first preference would be an in-person consultation with a doctor; if imagining they lived two hours from a doctor, 51% preferred a telephone consultation. The main objections to webcam consultations in the free text responses were privacy and security concerns relating to the possibility of the webcam consultation being recorded, saved, and potentially searchable and retrievable online.</p> <p>Conclusions</p> <p>This study is the first we are aware of that seeks the views of young people on telemedicine and access to sexual health services. Although only 29% of respondents were willing to have a webcam consultation, such a service may benefit youth who may not otherwise access a sexual health service. The acceptability of webcam consultations may be increased if medical clinics provide clear and accessible privacy policies ensuring that consultations will not be recorded or saved.</p

    Risk Factors for Ocular Infection with Chlamydia trachomatis in Children 6 Months following Mass Treatment in Tanzania

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    Trachoma control programs aim for high coverage of endemic communities with oral azithromycin to reduce the pool of infection with Chlamydia trachomatis. However, even with high coverage, infection is seen following treatment. In four communities in Tanzania, we followed every child aged under ten years from baseline through treatment to six months post-treatment. We determined who had infection at baseline and who still had or developed infection six months later. Coverage was over 95% in children in these communities, and infection in these children decreased by over 50% at six months. The study found that, at baseline, uninfected children who were treated had prevalence of infection at 6 months of 6%, but infected children who were treated had prevalence of infection of 22% at 6 months. Other risk factors for infection at 6 months included living in a household with other infected children, and living in a household with untreated children. Our data suggest that households with untreated children might be targeted for more intensive follow up to increase coverage and reduce subsequent infection in the community
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