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Polygonatum cyrtonema Hua is a traditional Chinese medicinal plant acclaimed for its therapeutic potential in diabetes and various chronic diseases. Its rhizomes are the main functional parts rich in secondary metabolites, such as flavonoids and saponins. But their quality varies by region, posing challenges for industrial and medicinal application of P. cyrtonema. In this study, 482 metabolites were identified in P. cyrtonema rhizome from Qingyuan and Xiushui counties. Cluster analysis showed that samples between these two regions had distinct secondary metabolite profiles. Machine learning methods, specifically support vector machine-recursive feature elimination and random forest, were utilized to further identify metabolite markers including flavonoids, phenolic acids, and lignans. Comparative transcriptomics and weighted gene co-expression analysis were performed to uncover potential candidate genes including CHI, UGT1, and PcOMT10/11/12/13 associated with these compounds. Functional assays using tobacco transient expression system revealed that PcOMT10/11/12/13 indeed impacted metabolic fluxes of the phenylpropanoid pathway and phenylpropanoid-related metabolites such as chrysoeriol-6,8-di-C-glucoside, syringaresinol-4'-O-glucopyranosid, and 1-O-Sinapoyl-D-glucose. These findings identified metabolite markers between these two regions and provided valuable genetic insights for engineering the biosynthesis of these compounds.
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Polygonatum , Polygonatum/genética , Análisis por Conglomerados , Flavonoides , Perfilación de la Expresión Génica , Aprendizaje AutomáticoRESUMEN
Human immunodeficiency virus type 1 CRF59_01B, identified in China in 2013, has been detected nationwide, exhibiting notably high prevalence in Guangzhou and its vicinity. This study aimed to unravel its origin and migration. A data set was established, incorporating all available CRF59_01B pol gene sequences and their metadata from Guangzhou and the public database. Bayesian phylogeographic analysis demonstrated that CRF59_01B originated in Shenzhen, the neighboring city of Guangzhou, around 1998 with posterior probability of 0.937. Molecular network analysis detected 1131 transmission links and showed a remarkably high clustering rate (78.9%). Substantial inter-city transmissions (26.5%, 300/1131) were observed between Shenzhen and Guangzhou while inter-region transmissions linked Guangzhou with South (46) and Southwest (64) China. The centre of Guangzhou was the hub of CRF59_01B transmission, including the inflow from Shenzhen (3.57 events/year) and outflow to the outskirts of Guangzhou (>2 events/year). The large-scale analysis revealed significant migration from Shenzhen to Guangzhou (5.08 events/year) and North China (0.59 events/year), and spread from Guangzhou to Central (0.47 events/year), East (0.42 events/year), South (0.76 events/year), Southwest China (0.76 events/year) and Shenzhen (1.89 events/year). Shenzhen and Guangzhou served as the origin and the hub of CRF59_01B circulation, emphasizing inter-city cooperation and data sharing to confine its nationwide diffusion.
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Epidemias , Infecciones por VIH , VIH-1 , Filogeografía , Humanos , China/epidemiología , VIH-1/genética , VIH-1/clasificación , Infecciones por VIH/epidemiología , Infecciones por VIH/virología , Infecciones por VIH/transmisión , Genotipo , Filogenia , Epidemiología Molecular , Masculino , Productos del Gen pol del Virus de la Inmunodeficiencia Humana/genética , FemeninoRESUMEN
A coherence sidelobe suppression method for a laser diode (LD) is proposed, based on the white-noise-current modulation and external cavity feedback. The theoretical model of the coherence of the white-noise-current-modulated external cavity laser (WECL) is established, which details the spectrum broadening mechanism and the coherence sidelobe suppression. At the noise current modulation, the coherence sidelobe induced by the internal cavity is lowered by the external cavity feedback, and the position of the coherence sidelobe induced by the external cavity is controlled with the cavity length, which can extend the coherence range without the sidelobes. The experimental results demonstrate that the 98.4% sidelobe suppression ratio (SLSR) of the WECL is achieved in dynamic interferometry, which is about 20% higher than that of the laser diode only with the white-noise-current modulation. This new, to the best of our knowledge, method can avoid the stray fringe cross talk caused by the multiple coherence sidelobes in the surface error measurements of parallel plates.
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AIM: Our study aims to provide an updated estimate of age- and sex-specific deaths and disability-adjusted life years (DALYs) associated with high body mass index (BMI) from 1990 to 2019 at the global, regional and national levels, and to forecast the global burden of disease attributed to high BMI from 2020 to 2035. METHODS: We used the data for the number of deaths, DALYs, age-standardized rate (per 100 000 population), percentage change and population attributable fraction from the Global Burden of Disease Study 2019 (GBD 2019) to examine the disease burden attributable to high BMI. We further applied an autoregressive integrated moving average (ARIMA) model to predict the disease burden for the period 2020-2035. RESULTS: From 1990 to 2019, the deaths and DALYs attributable to high BMI increased by 148% and 155.86% for men, and by 111.67% and 121.78% for women, respectively. In 2019, high BMI directly accounted for 8.52% [95% uncertainty intervals (UI) 0.05, 0.12] of all-cause deaths and 5.89% (95% UI 0.04, 0.08) of global DALYs. The highest death rates were observed in men aged 65-69 and women aged 75-79. The highest DALY rates were observed in the age group of 60-64 for both sexes. In 2019, the highest age-standardized deaths and DALY rates were observed in the Central Asia region [163.15 (95% UI 107.72, 223.58) per 100 000 people] and the Oceania region [4643.33 (95% UI 2835.66, 6902.6) per 100 000 people], respectively. Fiji [319.08 (95% UI 213.77, 444.96) per 100 000 people] and Kiribati [10 000.58 (95% UI 6266.55, 14159.2) per 100 000 people] had the highest age-standardized deaths and DALY rates, respectively. In 2019, the highest age-standardized rates of high BMI-related deaths and DALYs were observed in the middle-high socio-demographic index quintile and in the middle socio-demographic index quintile. The age-standardized deaths and DALY rates attributable to high BMI are projected to increase in both sexes from 2020 to 2035. The death rates are projected to rise from 62.79 to 64.31 per 100 000 people, while the DALY rates are projected to rise from 1946 to 2099.54 per 100 000 people. CONCLUSIONS: High BMIs significantly contribute to the global disease burden. The projected rise in deaths and DALY rates attributable to high BMI by 2035 highlights the critical need to address the impact of obesity on public health. Our study provides policymakers with up-to-date and comprehensive information.
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Índice de Masa Corporal , Carga Global de Enfermedades , Obesidad , Humanos , Masculino , Carga Global de Enfermedades/tendencias , Femenino , Persona de Mediana Edad , Anciano , Adulto , Obesidad/epidemiología , Obesidad/mortalidad , Años de Vida Ajustados por Discapacidad/tendencias , Salud Global/estadística & datos numéricos , Predicción , Anciano de 80 o más Años , Adulto Joven , Años de Vida Ajustados por Calidad de Vida , Causas de Muerte , Adolescente , Mortalidad/tendencias , Sobrepeso/epidemiología , Sobrepeso/mortalidadRESUMEN
This study aimed to investigate the impact of sexual partners' HIV serostatus awareness on the HIV acquisition among men who have sex with men (MSM) in Guangzhou, China. A nested case-control study was conducted based on a prospective cohort of MSM in Guangzhou. Within the cohort, individuals who underwent HIV seroconversion were identified as the case group, and each case was matched with four controls from the non-seroconverted participants. Information regarding the awareness of sexual partners' HIV serostatus over the preceding 6 months was gathered. Of the 161 participants, 36.0% were aware of the HIV serostatus of all their sexual partners. The practice of engaging in condomless anal sex with partners of unknown HIV serostatus and being aware of the HIV serostatus of only some casual partners were positively correlated with an elevated risk of acquiring HIV. Conversely, being fully aware of the HIV serostatus of all sexual partners, including regular ones, was associated with a diminished risk of HIV incidence. Regular communication with sexual partners regarding HIV testing outcomes, honest disclosure of one's own HIV serostatus, and refusal of sexual contact with partners of unknown HIV serostatus can potentially mitigate the risk of acquiring HIV among MSM.
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The considerable drought tolerance of wild cereal crop progenitors has diminished during domestication in the pursuit of higher productivity. Regaining this trait in cereal crops is essential for global food security but requires novel genetic insight. Here, we assessed the molecular evidence for natural variation of drought tolerance in wild barley (Hordeum spontaneum), wild emmer wheat (Triticum dicoccoides), and Brachypodium species collected from dry and moist habitats at Evolution Canyon, Israel (ECI). We report that prevailing moist vs dry conditions have differentially shaped the stomatal and photosynthetic traits of these wild cereals in their respective habitats. We present the genomic and transcriptomic evidence accounting for differences, including co-expression gene modules, correlated with physiological traits, and selective sweeps, driven by the xeric site conditions on the African Slope (AS) at ECI. Co-expression gene module 'circadian rhythm' was linked to significant drought-induced delay in flowering time in Brachypodium stacei genotypes. African Slope-specific differentially expressed genes are important in barley drought tolerance, verified by silencing Disease-Related Nonspecific Lipid Transfer 1 (DRN1), Nonphotochemical Quenching 4 (NPQ4), and Brassinosteroid-Responsive Ring-H1 (BRH1). Our results provide new genetic information for the breeding of resilient wheat and barley in a changing global climate with increasingly frequent drought events.
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Grano Comestible , Hordeum , Resistencia a la Sequía , Fitomejoramiento , Productos Agrícolas/genética , Sequías , Hordeum/genéticaRESUMEN
An intermodal-nonlinearity-induced time-frequency evolution model of high-power near-single-mode continuous-wave fiber lasers (NSM-CWHPFLs) was proposed to simulate the evolution of spectral characteristics and beam quality under the combined action of intermodal and intramodal nonlinear effects. The influence of fiber laser parameters on intermodal nonlinearities was analyzed, and a suppression method involving fiber coiling and seed mode characteristic optimization was proposed. Verification experiments were conducted with 20/400, 25/400, and 30/600 fiber-based NSM-CWHPFLs. The results demonstrate the accuracy of the theoretical model, clarify the physical mechanisms of nonlinear spectral sidebands, and demonstrate the comprehensive optimization of intermodal-nonlinearity-induced spectral distortion and mode degradation.
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An all-fiber orthogonal-polarized white-noise-modulated laser (AOWL) for short-coherence dynamic interferometry is proposed. Short-coherence laser is achieved by current modulating of a laser diode with the band-limited white noise. A pair of orthogonal-polarized lights with adjustable delay for short-coherence dynamic interferometry are output by the all-fiber structure. In the non-common-path interferometry, the AOWL can significantly suppress the interference signal clutter with 73% side lobe suppression ratio, that improves the positioning accuracy of zero optical path difference. The wavefront aberrations of a parallel plate are measured with the AOWL in the common-path dynamic interferometers, avoiding the fringe crosstalk.
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BACKGROUND: People living with HIV(PLWH) are deemed more vulnerable to the SARS-CoV-2 infection than the uninfected population. Vaccination is an effective measure for COVID-19 control, yet, little knowledge exists about the willingness of men who have sex with men (MSM) living with HIV in China to be vaccinated. METHODS: This cross-sectional study evaluated the willingness of MSM living with HIV to receive COVID-19 vaccination in six cities of Guangdong, China, from July to September 2020. Factors associated with willingness to receive COVID-19 vaccination using multivariable logistic regression. RESULTS: In total, we recruited 944 HIV-positive MSM with a mean age of 29.2 ± 7.7 years. Of all participants, 92.4% of them were willing to receive the COVID-19 vaccine. Participants who were separated, divorced, or widowed (adjusted OR: 5.29, 95%CI: 1.02-27.48), had an annual income higher than 9,000 USD (adjusted OR: 1.70, 95%CI: 1.01-2.86), had ever taken an HIV self-test (adjusted OR: 1.78, 95%CI: 1.07-2.95), had ever disclosed sexual orientation to a doctor/nurse (adjusted OR: 3.16, 95%CI: 1.33-7.50), had ever disclosed sexual orientation to others besides their male partners (adjusted OR: 2.18, 95%CI: 1.29-3.69) were more willing to receive the vaccine. Sex with a female partner in the past six months decreased the likelihood of willingness to receive the vaccine (adjusted OR: 0.40, 95%CI: 0.17-0.95). Economic burden, worry that my health condition could not bear the risk of receiving COVID-19 vaccines, and concern that the vaccination would affect the immune status and antiretroviral therapy were the main reasons for unwillingness to receive vaccination. CONCLUSION: Our study showed that HIV-positive MSM had a high willingness to receive the COVID-19 vaccination. Targeted interventions such as health education should be conducted among MSM with HIV infection to enhance COVID-19 vaccine uptake.
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COVID-19 , Infecciones por VIH , Minorías Sexuales y de Género , Masculino , Humanos , Femenino , Adulto Joven , Adulto , Homosexualidad Masculina , Vacunas contra la COVID-19/uso terapéutico , Infecciones por VIH/epidemiología , Infecciones por VIH/prevención & control , Estudios Transversales , COVID-19/epidemiología , COVID-19/prevención & control , Aceptación de la Atención de Salud , Encuestas y Cuestionarios , SARS-CoV-2 , Vacunación , China/epidemiologíaRESUMEN
The purpose of this study is to test the feasibility for deep CNN-based artificial intelligence methods for automatic classification of the mass margin and shape, while radiomic feature-based machine learning methods were also implemented in this study as baseline and for comparison study. In this retrospective study, 596 patients with breast mass that underwent mammography from 4 hospitals were enrolled from January 2012 to October 2019. Margin and shape of each mass were annotated according to BI-RADS by 2 experienced radiologists. Deep CNN-based AI was implemented for the classification task based on Resnet50. Balanced sampler and CBAM were also used to improve the performance of the Deep CNNs. As comparison, image texture features were extracted and then dimensionality reduction methods (such as PCA, ICA) and classical classifiers (such as SVM, DT, KNN) were used for classification task. Based on Python programming software, accuracy (ACC) was used to evaluate the performance of the model, and the model with the highest ACC value was selected. Deep CNN based on Resnet50 with balanced sampler and CBAM achieved the best performance for both margin and shape classification, with ACC of 0.838 and 0.874, respectively. For the radiomics-based machine learning, the best performance for margin was achieved as 0.676 by the combination of FA + RF, while the best performance for shape was 0.802 by the combination of PCA + MLP. The feasibility for automatic classification with coarse labeling of the mass shape and margin was testified with the deep CNN-based AI methods, while radiomic feature-based machine learning methods achieved inferior classification results.
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Inteligencia Artificial , Aprendizaje Automático , Humanos , Estudios Retrospectivos , Programas Informáticos , MamografíaRESUMEN
The WUSCHEL-Related Homeobox (WOX) family is a group of transcription factors unique to plants that play an important role in regulating key developmental processes such as stem cell maintenance and organ morphogenesis. As a rare and valuable Chinese herb, Dendrobium catenatum has a unique epiphytic lifestyle and growth and developmental characteristics, and a functional investigation of its WOX family genes can help to further understand the conserved and specific development of D. catenatum. In this study, we analyzed the phylogeny, spatio-temporal expression pattern and heterologous expression function of D. catenatum WOX family genes (DcWOX). The results showed that members of the D. catenatum WOX gene family could be divided into three evolutionary branches with significantly different tissue expression profiles. In transgenic Arabidopsis, overexpression of DcWOX4 resulted in significant dwarfism, pinnately leaf margins, and delayed flowering for 2 weeks; overexpression of DcWOX9 resulted in plant dwarfing, serrated leaf margin, delayed flowering for 1 week, and even male and female sterility in strong phenotype plants; overexpression of DcWOX11 caused curl downward leaf. The abnormal morphogenesis of DcWOX4/9/11 overexpression Arabidopsis leaves are related to the down-regulation of TCP family genes, CUC family genes and the up-regulation of KNOX family genes; Postponement of flowering is related to down-regulation of early flowering genes such as FT, SOC1 and CO. Therefore, this study showed that D. catenatum WOX family genes have important functions in regulating plant morphogenesis, leaf development, flowering time and fertility, further expanding the understanding of the WOX gene family function, and providing clues for the conservation and specificity during orchid development and evolution.
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Arabidopsis , Dendrobium , Dendrobium/genética , Fertilidad , Reproducción , Crecimiento y DesarrolloRESUMEN
In this paper, the amplified spontaneous emission (ASE) suppression in a 1050â nm fiber laser with a pump-sharing oscillator-amplifier (PSOA) structure is studied theoretically and experimentally. A theoretical model of a fiber laser with a PSOA structure is established. The characteristics of the ASE for the PSOA structure and the pump-independent oscillator-amplifier (PIOA) structure are compared and analyzed. The experimental results show that the ASE can be effectively suppressed by utilizing the PSOA structure, which agree with the simulation results. A 1050â nm high-power narrow-linewidth fiber laser with PSOA structure is demonstrated, in which the gain fiber lengths of the oscillator and amplifier are 1.6 m and 9 m, respectively, to ensure the interconnection of pump power between the oscillator and amplifier. Finally, the maximum output power of 3.1â kW has been achieved, the linewidth is 0.22â nm at 3â dB, the beam quality M2â ≈â 1.33, and the optical signal-to-noise ratio (OSNR) is 45.5â dB.
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Plant pathogens are one of the main factors hindering the breeding of cash crops. Pathogens, including oomycetes, fungus, and bacteria, secrete effectors as invasion weapons to successfully invade and propagate in host plants. Here, we review recent advances made in the field of plant-pathogen interaction models and the action mechanisms of phytopathogenic effectors. The review illustrates how effectors from different species use similar and distinct strategies to infect host plants. We classify the main action mechanisms of effectors in plant-pathogen interactions according to the infestation process: targeting physical barriers for disruption, creating conditions conducive to infestation, protecting or masking themselves, interfering with host cell physiological activity, and manipulating plant downstream immune responses. The investigation of the functioning of plant pathogen effectors contributes to improved understanding of the molecular mechanisms of plant-pathogen interactions. This understanding has important theoretical value and is of practical significance in plant pathology and disease resistance genetics and breeding.
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Oomicetos , Enfermedades de las Plantas , Productos Agrícolas , Interacciones Huésped-Patógeno , Oomicetos/fisiología , Fitomejoramiento , Enfermedades de las Plantas/microbiología , Inmunidad de la PlantaRESUMEN
Lipid-derived jasmonates (JAs) play a crucial role in a variety of plant development and defense mechanisms. In recent years, significant progress has been made toward understanding the JA signaling pathway. In this review, we discuss JA biosynthesis, as well as its core signaling pathway, termination mechanisms, and the evolutionary origin of JA signaling. JA regulates not only plant regeneration, reproductive growth, and vegetative growth but also the responses of plants to stresses, including pathogen as well as virus infection, herbivore attack, and abiotic stresses. We also focus on the JA signaling pathway, considering its crosstalk with the gibberellin (GA), auxin, and phytochrome signaling pathways for mediation of the trade-offs between growth and defense. In summary, JA signals regulate multiple outputs of plant defense and growth and act to balance growth and defense in order to adapt to complex environments.
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Ciclopentanos , Oxilipinas , Ciclopentanos/metabolismo , Regulación de la Expresión Génica de las Plantas , Oxilipinas/metabolismo , Reguladores del Crecimiento de las Plantas/metabolismo , Plantas/metabolismo , Transducción de Señal/fisiologíaRESUMEN
BACKGROUND: Dendrobium catenatum belongs to the Orchidaceae, and is a precious Chinese herbal medicine. In the past 20 years, D. catenatum industry has developed from an endangered medicinal plant to multi-billion dollar grade industry. The necrotrophic pathogen Sclerotium delphinii has a devastating effection on over 500 plant species, especially resulting in widespread infection and severe yield loss in the process of large-scale cultivation of D. catenatum. It has been widely reported that Jasmonate (JA) is involved in plant immunity to pathogens, but the mechanisms of JA-induced plant resistance to S. delphinii are unclear. RESULTS: In the present study, the role of JA in enhancing D. catenatum resistance to S. delphinii was investigated. We identified 2 COI1, 13 JAZ, and 12 MYC proteins in D. catenatum genome. Subsequently, systematic analyses containing phylogenetic relationship, gene structure, protein domain, and motif architecture of core JA pathway proteins were conducted in D. catenatum and the newly characterized homologs from its closely related orchid species Phalaenopsis equestris and Apostasia shenzhenica, along with the well-investigated homologs from Arabidopsis thaliana and Oryza sativa. Public RNA-seq data were investigated to analyze the expression patterns of D. catenatum core JA pathway genes in various tissues and organs. Transcriptome analysis of MeJA and S. delphinii treatment showed exogenous MeJA changed most of the expression of the above genes, and several key members, including DcJAZ1/2/5 and DcMYC2b, are involved in enhancing defense ability to S. delphinii in D. catenatum. CONCLUSIONS: The findings indicate exogenous MeJA treatment affects the expression level of DcJAZ1/2/5 and DcMYC2b, thereby enhancing D. catenatum resistance to S. delphinii. This research would be helpful for future functional identification of core JA pathway genes involved in breeding for disease resistance in D. catenatum.
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Basidiomycota/patogenicidad , Ciclopentanos/metabolismo , Dendrobium/microbiología , Oxilipinas/metabolismo , Inmunidad de la Planta/fisiología , Proteínas de Plantas/genética , Acetatos/farmacología , Ciclopentanos/farmacología , Dendrobium/efectos de los fármacos , Dendrobium/inmunología , Dendrobium/metabolismo , Resistencia a la Enfermedad/genética , Regulación de la Expresión Génica de las Plantas , Familia de Multigenes , Oxilipinas/farmacología , Filogenia , Enfermedades de las Plantas/inmunología , Enfermedades de las Plantas/microbiología , Proteínas de Plantas/inmunología , Transducción de Señal/genéticaRESUMEN
In this paper, Stokes light induced modulation instability (MI) in high power continuous wave (CW) fiber amplifiers is observed. The investigation shows that the Stokes light generated by inter-modal four wave mixing (IMFWM) and stimulated Raman scattering (SRS) in high power fiber amplifiers can be modulated by the signal light through XPM and cause MI. Then, a sideband will be generated around the second-order Raman frequency shift, which is amplified by SRS and shown as a train of pulses in time domain. It is shown that the frequency shift of the sideband will be influenced by IMFWM and SRS. In addition, the sideband was found to be blue-shifted with the increase of the power, which indicates that the frequency shift of the sideband is mainly depended on MI, while SRS plays the role of amplification.
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Recently, the growing interest in few-mode fibers in telecommunications and high-power lasers has stimulated the demand for fiber mode decomposition (MD). Here we present a fast fiber MD method with a lensless fiber-point-diffraction interferometer. The complex amplitude at the fiber end is achieved by the polarization phase-shifting technique and the lensless imaging technique. Then, the eigenmode coefficients are determined by the mode orthogonal operations of the complex amplitude. In the experiment, the SMF-28e fiber containing 10 linear polarized modes at the wavelength of 632.8 nm is studied for MD. The decomposition of the 50 * 50 pixels interferograms takes only 0.0168 s. The similarity of the intensity patterns of the testing light is larger than 97% before and after the MD. This new, to the best of our knowledge, method can achieve fast and accurate 10-mode MD without using any imaging systems.
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This publisher's note contains corrections to Opt. Lett.46, 2501 (2021)OPLEDP0146-959210.1364/OL.426833.
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BACKGROUND: HIV testing is an essential gateway to HIV prevention and treatment thus controlling the HIV epidemic. More innovative interventions are needed to increase HIV testing among men who have sex with men (MSM) since their testing rate is still low. We proposed an online HIV test results exchange mechanism whereby the one without a certified online HIV report will be asked to test HIV for exchanging HIV report with others. The exchange mechanism is developed as an extension to the existing online HIV testing service system. Through the extended system, MSM can obtain certified online HIV reports and exchange their reports with friends via WeChat. This study aims to assess effectiveness of the exchange mechanism to increase the HIV testing rate among MSM. METHODS: This study will use a cluster randomized controlled trial (RCT) design. Participants are recruited based on the unit of individual social network, the sender and the receivers of the HIV report. An individual social network is composed of one sender (ego) and one or more receivers (alters). In this study, MSM in an HIV testing clinic are recruited as potential egos and forwarded online reports to their WeChat friends voluntarily. Friends are invited to participate by report links and become alters. Ego and alters serve as a cluster and are randomized to the group using the certified online HIV report with exchange mechanism (intervention group) or without exchange mechanism (control group). Alters are the intervention targeting participants. The primary outcome is HIV testing rate. Other outcomes are sexual transmitted infections, sexual behaviors, HIV testing norms, stigma, risk perception and HIV report delivery. The outcomes will be assessed at baseline and follow-up questionnaires. Analysis will be according to intention to treat approach and using mixed-effect models with networks and individuals as random effects. DISCUSSION: This is the first study to evaluate the effectiveness of an HIV test result exchange mechanism to increase the HIV testing among MSM. This assessment of the intervention will also provide scientific evidence on other potential effects. Findings from this study will yield insights for sustainability driven by communities' intrinsic motivation. Trail registration: ClinicalTrials.gov NCT03984136. Registered 12 June 2019.
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Infecciones por VIH , Minorías Sexuales y de Género , Pruebas Diagnósticas de Rutina , Infecciones por VIH/diagnóstico , Infecciones por VIH/prevención & control , Prueba de VIH , Homosexualidad Masculina , Humanos , Masculino , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
BACKGROUND: Risk for transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to close contacts of infected persons has not been well estimated. OBJECTIVE: To evaluate the risk for transmission of SARS-CoV-2 to close contacts in different settings. DESIGN: Prospective cohort study. SETTING: Close contacts of persons infected with SARS-CoV-2 in Guangzhou, China. PARTICIPANTS: 3410 close contacts of 391 index cases were traced between 13 January and 6 March 2020. Data on the setting of the exposure, reverse transcriptase polymerase chain reaction testing, and clinical characteristics of index and secondary cases were collected. MEASUREMENT: Coronavirus disease 2019 (COVID-19) cases were confirmed by guidelines issued by China. Secondary attack rates in different settings were calculated. RESULTS: Among 3410 close contacts, 127 (3.7% [95% CI, 3.1% to 4.4%]) were secondarily infected. Of these 127 persons, 8 (6.3% [CI, 2.1% to 10.5%]) were asymptomatic. Of the 119 symptomatic cases, 20 (16.8%) were defined as mild, 87 (73.1%) as moderate, and 12 (10.1%) as severe or critical. Compared with the household setting (10.3%), the secondary attack rate was lower for exposures in health care settings (1.0%; odds ratio [OR], 0.09 [CI, 0.04 to 0.20]) and on public transportation (0.1%; OR, 0.01 [CI, 0.00 to 0.08]). The secondary attack rate increased with the severity of index cases, from 0.3% (CI, 0.0% to 1.0%) for asymptomatic to 3.3% (CI, 1.8% to 4.8%) for mild, 5.6% (CI, 4.4% to 6.8%) for moderate, and 6.2% (CI, 3.2% to 9.1%) for severe or critical cases. Index cases with expectoration were associated with higher risk for secondary infection (13.6% vs. 3.0% for index cases without expectoration; OR, 4.81 [CI, 3.35 to 6.93]). LIMITATION: There was potential recall bias regarding symptom onset among patients with COVID-19, and the symptoms and severity of index cases were not assessed at the time of exposure to contacts. CONCLUSION: Household contact was the main setting for transmission of SARS-CoV-2, and the risk for transmission of SARS-CoV-2 among close contacts increased with the severity of index cases. PRIMARY FUNDING SOURCE: Guangdong Province Higher Vocational Colleges and Schools Pearl River Scholar Funded Scheme.