138 research outputs found
Drug preparation, injection-related infections, and harm reduction practices among a national sample of individuals entering treatment for opioid use disorder
BACKGROUND: The rise in injection drug use in the USA has led to an increase in injection site infections. We performed a national survey of people who use drugs to evaluate common drug use preparation, harm reduction practices, and experiences with injection site infections.
METHODS: A survey was disseminated to members of the Survey of Key Informants\u27 Patients Program from 2021 to 2022 and distributed to patients 18 years or older newly entering one of 68 substance use disorder treatment programs across the USA with a primary diagnosis of an opioid use disorder. Participants were surveyed about practices when preparing and using drugs, along with self-reported infections and drug use complications.
RESULTS: 1289 participants responded to the survey. Sexually transmitted infections were common, with 37.6% reporting ever having had any sexually transmitted infection. Injection-associated infections had affected 63.4% of participants who had ever used injection drugs. Many respondents reported not seeking professional medical assistance for infection management, including 29% draining abscesses without seeking medical care and 22.8% obtaining antibiotics through non-healthcare sources. Non-sterile injection practices included sharing needles with others who were febrile or ill (18%), using needles previously used to drain wounds/abscesses (9.9%) for subsequent injection drug use, and licking needles (21.2%).
CONCLUSION: Patients entering treatment for opioid use disorder reported a high burden of infectious diseases. A number of easily-modifiable high risk behaviors for developing injection-related infections were identified. Efforts are needed to disseminate targeted harm reduction education to PWID on how to reduce their risks for injection-related infections
Disease ontogeny overshadows effects of climate and species interactions on population dynamics in a nonnative forest disease complex
Biotic threats to trees often arise from interactions among two or more species, frequency insects and fungi, that function together to defeat host defenses, secure resources and colonize new hosts. Feedbacks among plant enemies can have large positive feedbacks that can destabilize populations and permit outbreaks. Feedbacks can be rapid and direct (e.g. within trees or among years) or can arise from slowly developing changes in host resource quantity or quality at the scale of forest stands or landscapes. Climate may also influence system dynamics by altering feedbacks within or among species or through density independent effects. We evaluated major drivers of population dynamics of beech bark disease (BBD), an important forest disease in eastern deciduous forests of North America, using data from 28 study sites in the eastern United States monitored for up to 14 yr between 1979 and 1992. Both primary causal agents of BBD – the introduced felted beech scale. Cryptococcus fagisuga and native fungi Neonectria spp. – Showed strong simple density dependence in all study populations. Surprisingly, densities of scale insects and fungi had little or no effects on population growth rates of the other, despite their habit of living in close physical relationships. For both insects and fungi, ecologically important features of the density dependent functions (slope, carrying capacity and density independent variance ) were variable across sites. Climatic effects on density-dependent functions (and scatter around them) were evident but generally weak and variable. The most striking predictor of patterns in density dependence was duration since establishment of BBD in the region. Apparently BBD alters forests over decades in ways that strengthen self-regulation among causal agents without eliminating or even dramatically reducing host populations.This work was partially supported by the USDA Forest
Service Northeastern Research Station, grant 04-JV-11242328-
122.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1600-0587ab201
Inferring controls on the epidemiology of beech bark disease from spatial patterning of disease organisms
1 Spatial pattern in the distribution and abundance of organisms is an emergent
property of collective rates of reproduction, survival and movement of individuals
in a heterogeneous environment.
2 The form, intensity and scale of spatial patterning can be used to test hypotheses
regarding the relative importance of candidate processes to population dynamics.
3 Using 84 plots across eastern North America, we studied populations of two
associated plant parasites, the invasive felted beech scale Cryptococcus fagisuga
Lind. and the native Neonectria fungi, which together cause beech bark disease
(BBD).
4 We evaluated spatial patterns at the scales of trees within stands, stands within the
forest and forests within the landscape to examine four hypothetically important
factors in the ecology of the disease: (i) local contagion within stands; (ii) regional
contagion, or among patch infection–reinfection dynamics; (iii) variation in host
susceptibility linked to genetic and/or environmental heterogeneity; and (iv) climate
effects on population growth of BBD organisms.
5 Analyses revealed an unexpected lack of spatial aggregation in BBD populations
among trees, stands and forests. This implies that propagule pressure is generally
sufficiently high throughout the infested region of North America such that neither
trees nor stands are spared from the disease by dispersal limitations of the disease
agents. Furthermore, variation in tree and stand level susceptibility has minimal
impact on BBD dynamics and climate is not a conspicuous driver of abundance
within the core range of BBD.This work was partially supported by the USDA Forest Service Northeastern Research Station, grant 04-JV-11242328-122.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1461-9563/hb2013ab201
The Fire and Tree Mortality Database, for Empirical Modeling of Individual Tree Mortality After Fire
Wildland fires have a multitude of ecological effects in forests, woodlands, and savannas across the globe. A major focus of past research has been on tree mortality from fire, as trees provide a vast range of biological services. We assembled a database of individual-tree records from prescribed fires and wildfires in the United States. The Fire and Tree Mortality (FTM) database includes records from 164,293 individual trees with records of fire injury (crown scorch, bole char, etc.), tree diameter, and either mortality or top-kill up to ten years post-fire. Data span 142 species and 62 genera, from 409 fires occurring from 1981-2016. Additional variables such as insect attack are included when available. The FTM database can be used to evaluate individual fire-caused mortality models for pre-fire planning and post-fire decision support, to develop improved models, and to explore general patterns of individual fire-induced tree death. The database can also be used to identify knowledge gaps that could be addressed in future research
Predicting non-native insect impact: focusing on the trees to see the forest
Non-native organisms have invaded novel ecosystems for centuries, yet we have only a limited understanding of why their impacts vary widely from minor to severe. Predicting the impact of non-established or newly detected species could help focus biosecurity measures on species with the highest potential to cause widespread damage. However, predictive models require an understanding of potential drivers of impact and the appropriate level at which these drivers should be evaluated. Here, we used non-native, specialist herbivorous insects of forest ecosystems to test which factors drive impact and if there were differences based on whether they used woody angiosperms or conifers as hosts. We identified convergent and divergent patterns between the two host types indicating fundamental similarities and differences in their interactions with non-native insects. Evolutionary divergence time between native and novel hosts was a significant driver of insect impact for both host types but was modulated by different factors in the two systems. Beetles in the subfamily Scolytinae posed the highest risk to woody angiosperms, and different host traits influenced impact of specialists on conifers and woody angiosperms. Tree wood density was a significant predictor of host impact for woody angiosperms with intermediate densities (0.5–0.6 mg/mm3) associated with highest risk, whereas risk of impact was highest for conifers that coupled shade tolerance with drought intolerance. These results underscore the importance of identifying the relevant levels of biological organization and ecological interactions needed to develop accurate risk models for species that may arrive in novel ecosystems
Demography of an invading forest insect reunited with hosts and parasitoids from its native range
SUPPLEMENTARY MATERIALS : Explanation note: This file includes demographic data from native Sirex nigricornis woodwasps that were collected during our study. TABLE S1. Correlation matrix of bolt-level variables for P. resinosa and P. sylvestris. TABLE S2. Review of 10th and 90th percentile female body mass from insect species estimated from source paper cited, showing comparatively higher female S. noctilio body size variation. FIGURE S1. Examples of S. noctilio oviposition sites, lesion formation and emergence holes in the field. FIGURE S2. Top panels show a typical bolt from P. sylvestris with bark removed and S. noctilio emergence holes and oviposition sites identified. FIGURE S3. The number of S. noctilio emerging per tree was best described by a zero inflated negative binomial distribution (dotted line) with proportion of excess zeroes Φ = 0.32, μ = 75.39 and overdispersion parameter k = 0.35. FIGURE S4. Allometric relationships for S. noctilio in the Central NY data set: number of eggs and adult female mass (a; quantile regression), adult female mass and adult female length (b; fitted power function) and adult length and width of adult head capsule (c; linear regression).The Sirex woodwasp Sirex noctilio Fabricius (Hymenoptera: Siricidae), a widespread invasive pest of pines in the Southern Hemisphere, was first detected in North America in 2004. This study assessed the impacts of life history traits, host resistance and species interactions on the demography of S. noctilio in New York, Pennsylvania and Vermont, then compared key metrics to those found in the native range in Galicia, Spain. Many trees naturally attacked by S. noctilio in North America produced no adult woodwasps, with 5 of 38 infested trees (13%) sampled across six sites yielding 64% of emerging insects. Reproductive success was highest in the introduced host scots pine, Pinus sylvestris, but native red pine, Pinus resinosa, produced larger insects. Sirex noctilio required one or sometimes two years to develop and sex ratios were male biased, 1:2.98 ♀:♂. Body size and fecundity were highly variable, but generally lower than observed in non-native populations in the Southern Hemisphere. Hymenopteran parasitoids killed approximately 20% of S. noctilio larvae and 63% of emerging adults were colonized by the parasitic nematode Deladenus siricidicola, although no nematodes entered eggs. Demographic models suggested that S. noctilio in the northeastern USA have a higher potential for population growth than populations in the native range: estimated finite factor of increase, λ, was 4.17–4.52 (depending on tree species colonized), compared to λ = 1.57 in Spain.USDA Forest Service International Programs and OP RDE.https://neobiota.pensoft.netam2023Forestry and Agricultural Biotechnology Institute (FABI)Zoology and Entomolog
Epidemiology of Coxiella burnetii infection in Africa: a OneHealth systematic review
Background:
Q fever is a common cause of febrile illness and community-acquired pneumonia in resource-limited settings. Coxiella burnetii, the causative pathogen, is transmitted among varied host species, but the epidemiology of the organism in Africa is poorly understood. We conducted a systematic review of C. burnetii epidemiology in Africa from a “One Health” perspective to synthesize the published data and identify knowledge gaps.<p></p>
Methods/Principal Findings:
We searched nine databases to identify articles relevant to four key aspects of C. burnetii epidemiology in human and animal populations in Africa: infection prevalence; disease incidence; transmission risk factors; and infection control efforts. We identified 929 unique articles, 100 of which remained after full-text review. Of these, 41 articles describing 51 studies qualified for data extraction. Animal seroprevalence studies revealed infection by C. burnetii (≤13%) among cattle except for studies in Western and Middle Africa (18–55%). Small ruminant seroprevalence ranged from 11–33%. Human seroprevalence was <8% with the exception of studies among children and in Egypt (10–32%). Close contact with camels and rural residence were associated with increased seropositivity among humans. C. burnetii infection has been associated with livestock abortion. In human cohort studies, Q fever accounted for 2–9% of febrile illness hospitalizations and 1–3% of infective endocarditis cases. We found no studies of disease incidence estimates or disease control efforts.<p></p>
Conclusions/Significance:
C. burnetii infection is detected in humans and in a wide range of animal species across Africa, but seroprevalence varies widely by species and location. Risk factors underlying this variability are poorly understood as is the role of C. burnetii in livestock abortion. Q fever consistently accounts for a notable proportion of undifferentiated human febrile illness and infective endocarditis in cohort studies, but incidence estimates are lacking. C. burnetii presents a real yet underappreciated threat to human and animal health throughout Africa.<p></p>
Simplified Models for LHC New Physics Searches
This document proposes a collection of simplified models relevant to the
design of new-physics searches at the LHC and the characterization of their
results. Both ATLAS and CMS have already presented some results in terms of
simplified models, and we encourage them to continue and expand this effort,
which supplements both signature-based results and benchmark model
interpretations. A simplified model is defined by an effective Lagrangian
describing the interactions of a small number of new particles. Simplified
models can equally well be described by a small number of masses and
cross-sections. These parameters are directly related to collider physics
observables, making simplified models a particularly effective framework for
evaluating searches and a useful starting point for characterizing positive
signals of new physics. This document serves as an official summary of the
results from the "Topologies for Early LHC Searches" workshop, held at SLAC in
September of 2010, the purpose of which was to develop a set of representative
models that can be used to cover all relevant phase space in experimental
searches. Particular emphasis is placed on searches relevant for the first
~50-500 pb-1 of data and those motivated by supersymmetric models. This note
largely summarizes material posted at http://lhcnewphysics.org/, which includes
simplified model definitions, Monte Carlo material, and supporting contacts
within the theory community. We also comment on future developments that may be
useful as more data is gathered and analyzed by the experiments.Comment: 40 pages, 2 figures. This document is the official summary of results
from "Topologies for Early LHC Searches" workshop (SLAC, September 2010).
Supplementary material can be found at http://lhcnewphysics.or
Focus topics for the ECFA study on Higgs / Top / EW factories
In order to stimulate new engagement and trigger some concrete studies in
areas where further work would be beneficial towards fully understanding the
physics potential of an Higgs / Top / Electroweak factory, we propose
to define a set of focus topics. The general reasoning and the proposed topics
are described in this document.Comment: v3: fixed spelling of two author
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