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Innate immune responses induce hundreds of interferon-stimulated genes (ISGs). Viperin, a member of the radical S-adenosyl methionine (SAM) superfamily of enzymes, is the product of one such ISG that restricts the replication of a broad spectrum of viruses. Here, we report a previously unknown antiviral mechanism in which viperin activates a ribosome collision-dependent pathway that inhibits both cellular and viral RNA translation. We found that the radical SAM activity of viperin is required for translation inhibition and that this is mediated by viperin's enzymatic product, 3'-deoxy-3',4'-didehydro-CTP (ddhCTP). Viperin triggers ribosome collisions and activates the MAPKKK ZAK pathway that in turn activates the GCN2 arm of the integrated stress response pathway to inhibit translation. The study illustrates the importance of translational repression in the antiviral response and identifies viperin as a translation regulator in innate immunity.
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Oxirredutases atuantes sobre Doadores de Grupo CH-CH , Proteínas , Antivirais/farmacologia , Imunidade Inata , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/genética , Proteínas/metabolismo , Ribossomos/genética , Ribossomos/metabolismo , S-Adenosilmetionina , Replicação ViralRESUMO
Shotgun metagenomics is a powerful tool to identify antimicrobial resistance (AMR) genes in microbiomes but has the limitation that extrachromosomal DNA, such as plasmids, cannot be linked with the host bacterial chromosome. Here we present a comprehensive laboratory and bioinformatics pipeline HAM-ART (Hi-C Assisted Metagenomics for Antimicrobial Resistance Tracking) optimised for the generation of metagenome-assembled genomes including both chromosomal and extrachromosomal AMR genes. We demonstrate the performance of the pipeline in a study comparing 100 pig faecal microbiomes from low- and high-antimicrobial use pig farms (organic and conventional farms). We found significant differences in the distribution of AMR genes between low- and high-antimicrobial use farms including a plasmid-borne lincosamide resistance gene exclusive to high-antimicrobial use farms in three species of Lactobacilli. The bioinformatics pipeline code is available at https://github.com/lkalmar/HAM-ART.
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Anti-Infecciosos , Microbiota , Animais , Antibacterianos , Anti-Infecciosos/farmacologia , Farmacorresistência Bacteriana/genética , Metagenômica , SuínosRESUMO
We present compelling evidence for the existence of an extended innate viperin-dependent pathway, which provides crucial evidence for an adaptive response to viral agents, such as SARS-CoV-2. We show the in vivo biosynthesis of a family of novel endogenous cytosine metabolites with potential antiviral activities. Two-dimensional nuclear magnetic resonance (NMR) spectroscopy revealed a characteristic spin-system motif, indicating the presence of an extended panel of urinary metabolites during the acute viral replication phase. Mass spectrometry additionally enabled the characterization and quantification of the most abundant serum metabolites, showing the potential diagnostic value of the compounds for viral infections. In total, we unveiled ten nucleoside (cytosine- and uracil-based) analogue structures, eight of which were previously unknown in humans allowing us to propose a new extended viperin pathway for the innate production of antiviral compounds. The molecular structures of the nucleoside analogues and their correlation with an array of serum cytokines, including IFN-α2, IFN-γ, and IL-10, suggest an association with the viperin enzyme contributing to an ancient endogenous innate immune defense mechanism against viral infection.
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COVID-19 , Humanos , Estrutura Molecular , SARS-CoV-2 , Imunidade Inata , Citosina , Redes e Vias Metabólicas , AntiviraisRESUMO
Sequencing of plasma microbial cell-free DNA (mcfDNA) has gained increased acceptance as a valuable adjunct to standard-of-care testing for diagnosis of infections throughout the body. Here, we report the analytical and clinical validation of a novel application of mcfDNA sequencing, the non-invasive detection of seven common antimicrobial resistance (AMR) genetic markers in 18 important pathogens. The AMR markers include SCCmec, mecA, mecC, vanA, vanB, blaCTX-M, and blaKPC. The AMR markers were computationally linked to the pathogens detected. Analytical validation showed high reproducibility (100%), inclusivity (54 to 100%), and exclusivity (100%). Clinical accuracy was assessed with 114 unique plasma samples from patients at seven study sites with concordant culture results for target bacteria from a variety of specimen types and correlated with available phenotypic antimicrobial susceptibility test results and genotypic results. The positive percent agreement (PPA), negative percent agreement (NPA), and diagnostic yield (DY) were estimated for each AMR marker. DY was defined as the percentage of tests that yielded an actionable result of either detected or not detected. The results for the combination of SCCmec and mecA for staphylococci were PPA 19/20 (95.0%), NPA 21/22 (95.4%), DY 42/60 (70.0%); vanA for enterococci were PPA 3/3 (100%), NPA 2/2 (100%), DY 5/6 (83.3%); blaCTX-M for gram-negative bacilli were PPA 5/6 (83.3%), NPA 29/29 (100%), DY 35/49 (71.4%); and blaKPC for gram-negative bacilli were PPA 0/2 (0%), NPA: 23/23 (100%), DY 25/44 (56.8%). The addition of AMR capability to plasma mcfDNA sequencing should provide clinicians with an effective new culture-independent tool for optimization of therapy. IMPORTANCE: This manuscript is ideally suited for the Innovative Diagnostic Methods sections as it reports the analytical and clinical validation of a novel application of plasma microbial cell-free DNA sequencing for direct detection of seven selected antimicrobial resistance markers in 18 target pathogens. Clearly, it has potential clinical utility in optimizing therapy and was incorporated into the Karius test workflow in September 2023. In addition, the workflow could readily be adapted to expand the number of target bacteria and antimicrobial resistance markers as needed.
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BACKGROUND: Intravenous immunoglobulin (IVIg) is a critical replacement therapy for immunodeficiencies and immunomodulatory treatment for autoimmune and inflammatory diseases. Adequate supply of IVIg is a global issue, necessitating supply restrictions. In Australia, despite strict criteria for use, demand for IVIg has increased over time and exceeds domestic supply. OBJECTIVE: Factors associated with the upward trend in overall IVIg use were examined, including in the number of unique patients, IVIg dosing and treatment frequency and variations by prescribing discipline and disease group. METHODS: De-identified data of IVIg dispensed in the largest Australian state (New South Wales) from 2007 to 2013 were provided by Australian Red Cross Lifeblood. Trends and projections were calculated using log-linear regression of unique patients, treatment episodes and grams of IVIg for overall use and use stratified by discipline and disease group. RESULTS: During the study period, 169 453 treatment episodes were recorded for 12 547 unique patients accounting for 5 827 787 g of IVIg use. Overall, IVIg use increased by 12.0% (11.5-12.6%) per year representing a 97.7% increase (91.6-104%) over the study period. The highest growth was among neurological conditions (16.0% (14.9-17.1%) per year). An increase in the number of unique patients was the primary driver of this growth, augmented by increases in the frequency and average dose per treatment. CONCLUSIONS: Clinically acceptable measures to improve management of IVIg supply are needed including optimising dose, frequency and duration of treatment. Formal evaluation of IVIg versus alternatives, including cost-effectiveness and comparative efficacy, is warranted.
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Imunoglobulinas Intravenosas , Troca Plasmática , Humanos , Imunoglobulinas Intravenosas/uso terapêutico , New South Wales/epidemiologia , Austrália/epidemiologiaRESUMO
BACKGROUND: Data on the one-year postoperative revision, complication, and economic outcomes in a hospital setting after total shoulder arthroplasty (TSA) are sparse. METHODS: A retrospective cohort study using the Premier Healthcare Database, a hospital-billing data source, evaluated one-year postoperative revision, complication, and economic outcomes of reverse (RTSA) and anatomic (ATSA) TSA for patients who underwent the procedure from 2015 until 2021. All-cause revisits, including revision-related events (categorized as either irrigation and débridement or revision procedures and device removals) and shoulder/non-shoulder complications were collected. The incidences and costs of these revisits were evaluated. Generalized linear models were used to evaluate the associations between patient characteristics and revision and complication occurrences and costs. RESULTS: Among 51,478 RTSA and 34,623 ATSA patients (mean [standard deviation (SD)] ages RTSA 71.5 [8.1] years, ATSA 66.8 [9.0] years), one-year adjusted incidences of all-cause revisits, irrigation/débridement, revision procedures/device removals, and shoulder/non-shoulder complications were RTSA: 45.0% (95% confidence interval (CI): 44.6%-45.5%), 0.1% (95% CI: 0.1%-0.2%), 2.1% (95% CI: 2.0%-2.2%), and 17.8% (95% CI: 17.5%-18.1%) and ATSA: 42.3% (95% CI: 41.8%-42.9%), 0.2% (95% CI: 0.1%-0.2%), 1.9% (95% CI: 1.8%-2.1%), and 14.4% (95% CI: 14.0%-14.8%), respectively; shoulder-related complications were RTSA: 12.4% (95% CI: 12.1%-12.7%) and ATSA: 9.9% (95% CI: 9.6%-10.3%). Significant factors associated with a high risk of revisions and complications included, but were not limited to, chronic comorbidities and noncommercial insurance. Per patient, the mean (SD) total one-year hospital cost was $25,225 ($15,911) and $21,520 ($13,531) for RTSA and ATSA, respectively. Revision procedures and device removals were most costly, averaging $22,920 ($18,652) and $26,911 ($18,619) per procedure for RTSA and ATSA, respectively. Patients with revision-related events with infections had higher total hospital costs than patients without this event (RTSA: $60,887 (95% CI: $56,951-$64,823) and ATSA: $59,478 (95% CI: $52,312-$66,644)), equating to a mean difference of $36,148 with RTSA and $38,426 with ATSA. Significant factors associated with higher costs of revision-related events and complications included age, race, chronic comorbidities, and noncommercial insurance. CONCLUSIONS: Nearly 45% RTSA and 42% ATSA patients returned to the hospital, most often for shoulder/non-shoulder complications (overall 17.8% RTSA and 14.4% ATSA, and shoulder-related 12.4% RTSA and 9.9% ATSA). Revisions and device removals were most expensive ($22,920 RTSA and $26,911 ATSA). Infection complications requiring revision had the highest one-year hospital costs (â¼$60,000). This study highlights the need for technologies and surgical techniques that may help reduce TSA healthcare utilization and economic burden.
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Over the last 30 years, there has been significant investment in research and infrastructure aimed at mitigating the threat of newly emerging infectious diseases (NEID). Core epidemiological processes, such as outbreak investigations, however, have received little attention and have proceeded largely unchecked and unimproved. Using ethnographic material from an investigation into a cryptic encephalitis outbreak in the Brong-Ahafo Region of Ghana in 2010-2013, in this paper we trace processes of hypothesis building and their relationship to the organizational structures of the response. We demonstrate how commonly recurring features of NEID investigations produce selective pressures in hypothesis building that favor iterations of pre-existing "exciting" hypotheses and inhibit the pursuit of alternative hypotheses, regardless of relative likelihood. These findings contribute to the growing anthropological and science and technology studies (STS) literature on the epistemic communities that coalesce around suspected NEID outbreaks and highlight an urgent need for greater scrutiny of core epidemiological processes.
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Doenças Transmissíveis Emergentes , Humanos , Doenças Transmissíveis Emergentes/epidemiologia , Antropologia Médica , Surtos de Doenças , Gana/epidemiologia , Antropologia CulturalRESUMO
The first systematic exploration of the synthesis and reactivity of naphthoquinonynes is described. Routes to two regioisomeric Kobayashi-type naphthoquinonyne precursors have been developed, and the reactivity of the ensuing 6,7- and 5,6-aryne intermediates has been investigated. Remarkably, these studies have revealed that a broad range of cycloadditions, nucleophile additions and difunctionalizations can be achieved while maintaining the integrity of the highly sensitive quinone unit. The methodologies offer a powerful diversity oriented approach to C6 and C7 functionalized naphthoquinones, which are typically challenging to access. From a reactivity viewpoint, the study is significant because it demonstrates that aryne-based functionalizations can be utilized strategically in the presence of highly reactive and directly competing functionality.
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Animal welfare is usually excluded from life cycle assessments (LCAs) of farming systems because of limited consensus on how to measure it. Here, we constructed several LCA-compatible animal-welfare metrics and applied them to data we collected from 74 diverse breed-to-finish systems responsible for 5% of UK pig production. Some aspects of metric construction will always be subjective, such as how different aspects of welfare are aggregated, and what determines poor versus good welfare. We tested the sensitivity of individual farm rankings, and rankings of those same farms grouped by label type (memberships of quality-assurance schemes or product labelling), to a broad range of approaches to metric construction. We found farms with the same label types clustered together in rankings regardless of metric choice, and there was broad agreement across metrics on the rankings of individual farms. We found woodland and Organic systems typically perform better than those with no labelling and Red tractor labelling, and that outdoor-bred and outdoor-finished systems perform better than indoor-bred and slatted-finished systems, respectively. We conclude that if our goal is to identify relatively better and worse farming systems for animal welfare, exactly how LCA welfare metrics are constructed may be less important than commonly perceived.
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Criação de Animais Domésticos , Animais Domésticos , Animais , Suínos , Fazendas , Bem-Estar do AnimalRESUMO
Since the emergence of SARS-CoV-2 in 2019 through to mid-2021, much of the Australian population lived in a COVID-19-free environment. This followed the broadly successful implementation of a strong suppression strategy, including international border closures. With the availability of COVID-19 vaccines in early 2021, the national government sought to transition from a state of minimal incidence and strong suppression activities to one of high vaccine coverage and reduced restrictions but with still-manageable transmission. This transition is articulated in the national 're-opening' plan released in July 2021. Here, we report on the dynamic modelling study that directly informed policies within the national re-opening plan including the identification of priority age groups for vaccination, target vaccine coverage thresholds and the anticipated requirements for continued public health measures-assuming circulation of the Delta SARS-CoV-2 variant. Our findings demonstrated that adult vaccine coverage needed to be at least 60% to minimize public health and clinical impacts following the establishment of community transmission. They also supported the need for continued application of test-trace-isolate-quarantine and social measures during the vaccine roll-out phase and beyond.
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Vacinas contra COVID-19 , COVID-19 , Adulto , Humanos , SARS-CoV-2 , Incidência , COVID-19/epidemiologia , COVID-19/prevenção & controle , Austrália/epidemiologiaRESUMO
Mycobacterium bovis (M. bovis) is a causative agent of bovine tuberculosis, a significant source of morbidity and mortality in the global cattle industry. The Randomised Badger Culling Trial was a field experiment carried out between 1998 and 2005 in the South West of England. As part of this trial, M. bovis isolates were collected from contemporaneous and overlapping populations of badgers and cattle within ten defined trial areas. We combined whole genome sequences from 1,442 isolates with location and cattle movement data, identifying transmission clusters and inferred rates and routes of transmission of M. bovis. Most trial areas contained a single transmission cluster that had been established shortly before sampling, often contemporaneous with the expansion of bovine tuberculosis in the 1980s. The estimated rate of transmission from badger to cattle was approximately two times higher than from cattle to badger, and the rate of within-species transmission considerably exceeded these for both species. We identified long distance transmission events linked to cattle movement, recurrence of herd breakdown by infection within the same transmission clusters and superspreader events driven by cattle but not badgers. Overall, our data suggests that the transmission clusters in different parts of South West England that are still evident today were established by long-distance seeding events involving cattle movement, not by recrudescence from a long-established wildlife reservoir. Clusters are maintained primarily by within-species transmission, with less frequent spill-over both from badger to cattle and cattle to badger.
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Reservatórios de Doenças/microbiologia , Mustelidae/microbiologia , Mycobacterium bovis/isolamento & purificação , Tuberculose Bovina/transmissão , Animais , Bovinos , Ensaios Clínicos Veterinários como Assunto , Inglaterra/epidemiologia , Distribuição Aleatória , Tuberculose Bovina/epidemiologia , Tuberculose Bovina/microbiologiaRESUMO
In epidemiology, endemicity characterizes sustained pathogen circulation in a geographical area, which involves a circulation that is not being maintained by external introductions. Because it could potentially shape the design of public health interventions, there is an interest in fully uncovering the endemic pattern of a disease. Here, we use a phylogeographic approach to investigate the endemic signature of rabies virus (RABV) circulation in Cambodia. Cambodia is located in one of the most affected regions by rabies in the world, but RABV circulation between and within Southeast Asian countries remains understudied. Our analyses are based on a new comprehensive data set of 199 RABV genomes collected between 2014 and 2017 as well as previously published Southeast Asian RABV sequences. We show that most Cambodian sequences belong to a distinct clade that has been circulating almost exclusively in Cambodia. Our results thus point towards rabies circulation in Cambodia that does not rely on external introductions. We further characterize within-Cambodia RABV circulation by estimating lineage dispersal metrics that appear to be similar to other settings, and by performing landscape phylogeographic analyses to investigate environmental factors impacting the dispersal dynamic of viral lineages. The latter analyses do not lead to the identification of environmental variables that would be associated with the heterogeneity of viral lineage dispersal velocities, which calls for a better understanding of local dog ecology and further investigations of the potential drivers of RABV spread in the region. Overall, our study illustrates how phylogeographic investigations can be performed to assess and characterize viral endemicity in a context of relatively limited data.
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Vírus da Raiva , Raiva , Animais , Cães , Raiva/epidemiologia , Raiva/veterinária , Camboja/epidemiologia , Vírus da Raiva/genética , Filogeografia , Análise de Sequência de DNA , FilogeniaRESUMO
BACKGROUND: The distribution of the duration that clinical cases of COVID-19 occupy hospital beds (the 'length of stay') is a key factor in determining how incident caseloads translate into health system burden. Robust estimation of length of stay in real-time requires the use of survival methods that can account for right-censoring induced by yet unobserved events in patient progression (e.g. discharge, death). In this study, we estimate in real-time the length of stay distributions of hospitalised COVID-19 cases in New South Wales, Australia, comparing estimates between a period where Delta was the dominant variant and a subsequent period where Omicron was dominant. METHODS: Using data on the hospital stays of 19,574 individuals who tested positive to COVID-19 prior to admission, we performed a competing-risk survival analysis of COVID-19 clinical progression. RESULTS: During the mixed Omicron-Delta epidemic, we found that the mean length of stay for individuals who were discharged directly from ward without an ICU stay was, for age groups 0-39, 40-69 and 70 +, respectively, 2.16 (95% CI: 2.12-2.21), 3.93 (95% CI: 3.78-4.07) and 7.61 days (95% CI: 7.31-8.01), compared to 3.60 (95% CI: 3.48-3.81), 5.78 (95% CI: 5.59-5.99) and 12.31 days (95% CI: 11.75-12.95) across the preceding Delta epidemic (1 July 2021-15 December 2021). We also considered data on the stays of individuals within the Hunter New England Local Health District, where it was reported that Omicron was the only circulating variant, and found mean ward-to-discharge length of stays of 2.05 (95% CI: 1.80-2.30), 2.92 (95% CI: 2.50-3.67) and 6.02 days (95% CI: 4.91-7.01) for the same age groups. CONCLUSIONS: Hospital length of stay was substantially reduced across all clinical pathways during a mixed Omicron-Delta epidemic compared to a prior Delta epidemic, contributing to a lessened health system burden despite a greatly increased infection burden. Our results demonstrate the utility of survival analysis in producing real-time estimates of hospital length of stay for assisting in situational assessment and planning of the COVID-19 response.
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COVID-19 , SARS-CoV-2 , Humanos , New South Wales/epidemiologia , COVID-19/epidemiologia , Austrália , HospitaisRESUMO
Clear recommendations are needed on when repeat blood cultures (BCxs) in hospitalized children with cancer should be obtained. We reviewed all BCx obtained on the Hematology-Oncology Unit at Riley Hospital for Children, regardless of reason for patient admission or neutropenia status, between January 2015 and February 2021. Patients with positive BCx within 48 hours of initial cultures, history of stem cell transplant, or admitted to the intensive care unit were excluded. Medical records of patients with new positive BCx drawn >48 hours after initial BCx were reviewed. Seven (1.2%) hospitalization episodes grew new pathogens, or commensals treated as pathogens, on cultures beyond 48 hours. All patients with new, true pathogens were hemodynamically unstable or had recurrent fever when the new positive BCx was obtained. Twenty-three (4.0%) hospitalization episodes had contaminant cultures beyond 48 hours, with 74 (5.4%) of 1362 BCx collected beyond 48 hours being contaminated, resulting in an additional cost of $210,519 from increased length of stay. In conclusion, repeat BCx beyond 48 hours in pediatric hematology-oncology patients with negative initial cultures are low yield and costly. Repeat BCx can be safely and cost-effectively ceased after 48 hours of negative cultures in hemodynamically and clinically stable patients.
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Bacteriemia , Hematologia , Neutropenia , Criança , Humanos , Hemocultura/métodos , Análise Custo-Benefício , Estudos Retrospectivos , Estudos de CoortesRESUMO
Livestock value chains constitute a source of livelihood for meat and milk value chain actors in Ethiopia, from dairy farmers to other associated value chain actors such as milk traders, abattoir workers, public health officials, veterinarians, butcheries selling meats, milk cooperatives, artisanal milk processors, and transporters. The development of these livestock value chains, however, is constrained by poor food safety and quality, while consumers are also exposed to public health risks due to milk and meat value chain actors' food handling and hygiene practices.This study used Photovoice and participant observation to explore meat and milk value chain actors' food handling and hygiene practices in suburban areas of Addis Ababa and neighbouring Oromia in Ethiopia. The results of this study reveal that milk and meat value chain actors' food handling practices are not aligned with the recommended Ethiopian food safety and quality standards. Low compliance with food safety and quality standards reflected a combination of factors such as lack of incentives, poor road infrastructure and low enforcement of food safety standards.Participatory and visual research methods enable a researcher to collect context-aware data that can lead to the development of policies and intervention strategies that reflect local needs and priorities. The results of this study affirm the need to identify socially acceptable and economically viable policies and intervention strategies that are acceptable to all chain actors; and suggest there is an imperative to train milk and meat value chain actors on good hygiene handling practices, improve road infrastructure, and facilitate access equipment such as fridges and freezers that can contribute to maintaining food safety and quality.
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Higiene , Leite , Humanos , Animais , Fazendas , Etiópia , Carne , Inocuidade dos Alimentos , Manipulação de AlimentosRESUMO
BACKGROUND: Neisseria gonorrhoeae (NG) can lead to serious reproductive and sexual health outcomes, and the annual number of NG notifications in Australia increased steadily from 10329 in 2010 to 29549 by 2020. Australian populations most affected are urban men who have sex with men and First Nations peoples living in remote areas, and a resurgence in urban heterosexuals has been observed since 2012. METHODS: A case series analysis of Queensland NG isolates (2010-15) exploring temporal trends and antimicrobial resistance by demographic and geographic distribution and genotype was performed. Proportions describe age, sex, strain, genogroup (NG multi-antigen sequence typing), region, swab site, antimicrobial sensitivity and isolate rates per 100000 population. Dominant genogroups were identified. RESULTS: Among 3953 isolates, the median age was 25years (IQR 20-34years) and most (n =2871/3915, 73%) were men. Brisbane city (68.8) and Far North Queensland (54.1) excluding Cairns showed the highest rates. Forty-six genogroups were documented, seven (G2992, G6876, G1415, G4186, G5, G1407 and G6937) comprised half of all isolates. The predominant male genogroup was G2992 (16%), and G6876 (20%) for females; G5 was predominantly male from 2010 to 2011, but equal in both sexes from 2012 to 2015. CONCLUSION: Considerable temporal, geographical and demographical diversity was observed in Queensland NG isolates, which has public health implications. Certain genogroups are more transient than others, and evidence suggests bridging from male-dominant networks to heterosexual networks. Molecular surveillance can enhance tracking the epidemiology and movement of NG in Australia, highlighting the necessity of genotyping to expose potentially prevalent strains circulating in undetected or underrepresented networks by current screening methods.
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Gonorreia , Minorias Sexuais e de Gênero , Feminino , Humanos , Masculino , Adulto Jovem , Adulto , Neisseria gonorrhoeae , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Gonorreia/tratamento farmacológico , Gonorreia/epidemiologia , Homossexualidade Masculina , Queensland/epidemiologia , Epidemiologia Molecular/métodos , Farmacorresistência Bacteriana/genética , Austrália , GenótipoRESUMO
BACKGROUND: A gonococcal vaccine is urgently needed due to increasing gonorrhea incidence and emerging multidrug-resistant gonococcal strains worldwide. Men who have sex with men (MSM) have among the highest incidences of gonorrhea and may be a key target population for vaccination when available. METHODS: An individual-based, anatomical site-specific mathematical model was used to simulate Neisseria gonorrhoeae transmission in a population of 10â 000 MSM. The impact of vaccination on gonorrhea prevalence was assessed. RESULTS: With a gonococcal vaccine of 100% or 50% protective efficacy, gonorrhea prevalence could be reduced by 94% or 62%, respectively, within 2 years if 30% of MSM are vaccinated on presentation for sexually transmitted infection (STI) testing. Elimination of gonorrhea is possible within 8 years with vaccines ofâ ≥â 50% efficacy lasting 2 years, providing a booster vaccination is available every 3 years on average. A vaccine's impact may be reduced if it is not effective at all anatomical sites. CONCLUSIONS: Our study indicates that with a vaccine of modest efficacy and an immunization strategy that targets MSM presenting for STI screening, the prevalence of gonorrhea in this population could be rapidly and substantially reduced.
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Gonorreia , Minorias Sexuais e de Gênero , Vacinas Bacterianas , Gonorreia/epidemiologia , Gonorreia/prevenção & controle , Homossexualidade Masculina , Humanos , Incidência , Masculino , Neisseria gonorrhoeaeRESUMO
Non-linear processes such as four-wave-mixing have become instrumental in attosecond EUV spectroscopy. Using EUV high harmonics in conjunction with collinear near-infrared and mid-infrared fields, we extended this approach to high-order-mixing between three colors. Specifically, we find that atomic resonances in neon exhibit a significant cross section for six-wave mixing. The MIR probe frequency tunability in our multicolor scheme is employed to access several optically dark resonances and probe the quantum beat of a coherent electronic wavepacket using background-free EUV emission as a diagnostic. This technique can be easily extended to other atomic and molecular systems, and opens the door to multi-dimensional non-linear spectroscopy.
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The SARS-CoV-2 pathogen is currently spreading worldwide and its propensity for presymptomatic and asymptomatic transmission makes it difficult to control. The control measures adopted in several countries aim at isolating individuals once diagnosed, limiting their social interactions and consequently their transmission probability. These interventions, which have a strong impact on the disease dynamics, can affect the inference of the epidemiological quantities. We first present a theoretical explanation of the effect caused by non-pharmaceutical intervention measures on the mean serial and generation intervals. Then, in a simulation study, we vary the assumed efficacy of control measures and quantify the effect on the mean and variance of realized generation and serial intervals. The simulation results show that the realized serial and generation intervals both depend on control measures and their values contract according to the efficacy of the intervention strategies. Interestingly, the mean serial interval differs from the mean generation interval. The deviation between these two values depends on two factors. First, the number of undiagnosed infectious individuals. Second, the relationship between infectiousness, symptom onset and timing of isolation. Similarly, the standard deviations of realized serial and generation intervals do not coincide, with the former shorter than the latter on average. The findings of this study are directly relevant to estimates performed for the current COVID-19 pandemic. In particular, the effective reproduction number is often inferred using both daily incidence data and the generation interval. Failing to account for either contraction or mis-specification by using the serial interval could lead to biased estimates of the effective reproduction number. Consequently, this might affect the choices made by decision makers when deciding which control measures to apply based on the value of the quantity thereof.
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COVID-19/epidemiologia , COVID-19/prevenção & controle , Modelos Estatísticos , Pandemias/prevenção & controle , SARS-CoV-2 , Infecções Assintomáticas/epidemiologia , Número Básico de Reprodução/estatística & dados numéricos , COVID-19/transmissão , Biologia Computacional , Simulação por Computador , Humanos , Incidência , Prevalência , Processos Estocásticos , Fatores de TempoRESUMO
The ability to treat gonorrhoea with current first-line drugs is threatened by the global spread of extensively drug resistant (XDR) Neisseria gonorrhoeae (NG) strains. In Australia, urban transmission is high among men who have sex with men (MSM) and importation of an XDR NG strain in this population could result in an epidemic that would be difficult and costly to control. An individual-based, anatomical site-specific mathematical model of NG transmission among Australian MSM was developed and used to evaluate the potential for elimination of an imported NG strain under a range of case-based and population-based test-and-treat strategies. When initiated upon detection of the imported strain, these strategies enhance the probability of elimination and reduce the outbreak size compared with current practice (current testing levels and no contact tracing). The most effective strategies combine testing targeted at regular and casual partners with increased rates of population testing. However, even with the most effective strategies, outbreaks can persist for up to 2 years post-detection. Our simulations suggest that local elimination of imported NG strains can be achieved with high probability using combined case-based and population-based test-and-treat strategies. These strategies may be an effective means of preserving current treatments in the event of wider XDR NG emergence.