Optically Controlled Ultrafast Terahertz Metadevices with Ultralow Pump Threshold

Arming metasurface with active materials furnishes a feasible solution to dynamically control over terahertz (THz) waves, which is extremely significant for the realization of upcoming sixth generation telecommunications. However, the present active materials are mainly limited to single external driving field, hindering the capability of metasurface for flexible manipulation of THz waves. Besides, less attention has been paid to the energy question how to significantly reduce the pump threshold for achieving the desired function. Here, a germanium (Ge) hybrid Fano metasurface under dual-stimulus control is experimentally demonstrated. Photoexcitation of Ge thin film enables 100% modulation depth of Fano resonance and ultrafast switching time within 10 ps. By adding current-bias, the pump threshold to modulate the metasurface is greatly reduced from 1600 to 200 µJ cm^-2 . Different from the optical modulation independent of film thickness, it is found that the current function is in proportion with the thickness of Ge thin film. Moreover, it is demonstrated that compared to the single optical-stimulus, the THz amplitude modulation is increased by 56.3% under dual-stimulus function. This work naturally improves the flexibility and practicality of Ge-based metadevice and inspires more innovations to boost the development of switchable sensing, lasing spacer, and nonlinear systems.

Protocol for the economic evaluation of COVID-19 pandemic response policies

INTRODUCTION

Several treatment options are available for COVID-19 to date. However, the use of a combination of non-pharmaceutical interventions (NPIs) is necessary for jurisdictions to contain its spread. Although the implementation cost of NPIs may be low from the healthcare system perspective, it can be costly when considering the indirect costs from the societal perspective. COVID-19 vaccination campaigns have begun in several countries worldwide. Nonetheless, the quantity of vaccines available remain limited over the next 1 to 2 years. A tool for informing vaccine prioritisation that considers both cost and effectiveness will be highly useful. This study aims to identify the most cost-effective combination of COVID-19 response policies, using Singapore as an example.

METHODS AND ANALYSIS

An age-stratified Susceptible-Exposed-Infectious-Recovered model will be used to generate the number of infections stratified by disease severity under different intervention scenarios. Polices of interest include test-trace-isolate, travel restriction, compulsory face mask and hygiene practices, social distancing, dexamethasone/remdesivir therapy and vaccination. The latest phase 3 trial results and the WHO Target Product Profiles for COVID-19 vaccines will be used to model vaccine characteristics. A cost (expected resource utilisation and productivity losses) and quality-adjusted life years (QALYs) will be attached to these outputs for a cost-utility analysis. The primary outcome measure will be the incremental cost-effectiveness ratio generated from the incremental cost of policy alternatives expressed as a ratio of the incremental benefits (QALYs gained). Efficacy of policy options will be gathered from literature review and from its observed impacts in Singapore. Cost data will be gathered from healthcare institutions, Ministry of Health and published data. Sensitivity analysis such as threshold analysis and scenario analysis will be conducted.

ETHICS AND DISSEMINATION

Ethics approval was not required for this study. The study findings will be disseminated through peer-reviewed journals.

The RNase MCPIP3 promotes skin inflammation by orchestrating myeloid cytokine response

CCCH zinc finger proteins resolve immune responses by degrading the mRNAs of inflammatory cytokines such as tumor necrosis factor (TNF) and interleukin (IL)-6. Here we report that one such family member, monocyte chemotactic protein-induced protein 3 (MCPIP3, also named ZC3H12C or Regnase-3), promotes skin inflammation by simultaneously enhancing TNF in macrophages and repressing IL-6 in plasmacytoid dendritic cells (pDCs). MCPIP3 is positively associated with psoriasis pathogenesis, and highly expressed by macrophages and pDCs. MCPIP3-deficient macrophages produce less TNF and IL-12p40. However, MCPIP3-deficient pDCs secrete significantly more IL-6. This enhanced intradermal IL-6 may alleviate imiquimod-induced skin inflammation. As a result, MCPIP3-deficient mice are protected from imiquimod-induced psoriasiform lesions. Furthermore, early exposure to pDC-derived IL-6 suppresses macrophage-derived TNF and IL-12p40. Mechanistically, MCPIP3 could directly degrade mRNAs of IL-6, Regnase-1, and IκBζ. In turn, Regnase-1 could degrade MCPIP3 mRNAs. Our study identifies a critical post-transcriptional mechanism that synchronizes myeloid cytokine secretion to initiate autoimmune skin inflammation.

Zinc finger proteins are involved in the resolution of immune responses and function by degrading mRNA of inflammatory cytokines. Here the authors show MCPIP3 promotes skin inflammation via modification of cytokine profiles in pDCs and macrophages.

Avoiding Trouble Ahead: Lessons Learned and Suggestions for Economic Evaluations of COVID-19 Vaccines

With vaccines for coronavirus disease 2019 (COVID-19) being introduced in countries across the world, policy makers are facing many practical considerations about how best to implement a vaccination programme. The supply of vaccines is insufficient for the global population, so decisions must be made as to which groups are prioritised for any vaccination and when. Furthermore, the aims of vaccination programmes will differ between countries, with some prioritising economic benefits that could stem from the relaxation of non-pharmaceutical interventions and others seeking simply to reduce the number of COVID-19 cases or deaths. This paper aims to share the experiences and lessons learned from conducting economic evaluations in Singapore and Thailand on hypothetical COVID-19 vaccines to provide a basis for other countries to develop their own contextualised economic evaluations, with particular focus on the key uncertainties, technical challenges, and characteristics that modellers should consider in partnership with key stakeholders. Which vaccines, vaccination strategies, and policy responses are most economically beneficial remains uncertain. It is therefore important for all governments to conduct their own analyses to inform local policy responses to COVID-19, including the implementation of COVID-19 vaccines in both the short and the long run. It is essential that such studies are designed, and ideally conducted, before vaccines are introduced so that policy decisions and implementation procedures are not delayed.

Increased photokeratitis during the coronavirus disease 2019 pandemic: Clinical and epidemiological features and preventive measures

An increased incidence of photokeratitis has occurred during the coronavirus disease 2019 (COVID-19) pandemic due to improper and unprotected use of ultraviolet lamps. Here, we summarize the clinical and epidemiological features of this increased incidence of photokeratitis and share advice in using health education to prevent it.We collected data from patients diagnosed with photokeratitis from October 7, 2019 to December 1, 2019, and from February 17, 2020 to April 12, 2020, and compared the frequency of onset, site of ultraviolet radiation (UVR) exposure, reason for exposure, exposure time, and recovery time. We also implemented and evaluated multiple measures of public health education to prevent increased disease.After the COVID-19 outbreak, the frequency of onset of photokeratitis increased significantly, especially among young women. The main reason for UVR exposure changed from welding to disinfection. The incidence sites varied, and the exposure time was longer. As a result, patients needed a longer time to recover. Positive health education was an useful and convenient measure to prevent the disease.While the COVID-19 pandemic is ongoing, more attention should be paid to public health and implement positive measures to prevent photokeratitis.

Ultra-thin and broadband surface wave meta-absorber

Perfect absorbers are highly desired in many engineering and military applications, including radar cross section (RCS) reduction, cloaking devices, and sensor detectors. However, most types of present absorbers can only absorb space propagation waves, but absorption for surface waves has not been researched intensively. Surface waves are easily excited on the interfaces between metal and dielectrics for electronic devices, which decreases their working performances due to the electromagnetic disturbances. Thus, it is of great significance to design appropriate absorbers to dissipate undesirable surface waves. Here, we propose the concept of a surface wave absorber, analyze its working principle, and prove its good performances experimentally. To demonstrate our concept, we design and fabricate a realistic surface wave absorber that is fixed on a metal surface. Experiments are performed to verify its electromagnetic characteristics. The results show that our designed meta-absorber can achieve an excellent surface wave absorption within a wide frequency window (5.8-11.2 GHz) and exhibit a very high efficiency over than 90%, but only with the thickness of 1 mm (0.028 λ). Our device can help to solve the issues of absorption at large angles, and it can find wide applications in large antenna array design and other communication systems.

Transcriptional regulation of the mannitol phosphotransferase system operon by the ferric uptake regulator (Fur) in Vibrio cholerae El Tor serogroup O1

The phosphoenolpyruvate (PEP): carbohydrate phosphotransferase system (PTS) allows bacteria to use various carbohydrates as energy resources including mannitol. The mannitol-specific PTS transporter in Vibrio cholerae is encoded by the mtlADR operon. Expression of the mtl operon has been shown to be strictly regulated by CRP, MtlS, and MtlR. In the present study, we investigated the regulation of mtlADR by the ferric uptake regulator (Fur). The results showed that Fur binds to the promoter-proximal DNA region of mtlADR to repress its transcription independent of iron, in mannitol-containing growth medium. The capacity for mannitol fermentation was significantly increased in Δfur relative to that of WT for normal and iron-replete growth media. The level of organic acids produced by Δfur was significantly enhanced relative to that produced by the WT strain in the normal and iron-replete media but not in an iron-starved medium. The results provided for a deeper understanding of the regulation of mtlADR in V. cholerae.

High-performance meta-absorber for the surface wave under the spoof surface plasmon polariton mode

Perfect absorbers are highly desired in many engineering and military applications, including radar cross section (RCS) reduction, cloaking devices, and sensor detectors. However, most types of present absorbers can only absorb space propagation waves, yet absorption for the surface wave (SW) has not been researched intensively. In reality, when the space wave illuminates on the metal under large oblique angles, surface waves can be excited on the interface between metal and dielectric and thus would increase the RCS and influence the stealth performance. Here, based on the wave vector and impedance matching theories, we propose a broadband absorber for the surface wave under spoof surface plasmon polariton (SSPP) mode. The former theory ensures that surface waves can enter the absorber efficiently, and the latter guarantees perfect absorption. The experimental results indicate that our absorber can achieve a broadband (9.4-18 GHz) performance with an absorption ratio better than 90%, which is in great agreement with the simulations. Therefore, our device can be applied in RCS reduction for the metal devices, antenna array decoupling and many other applications. Also, this work provides a unique methodology to design new types of broadband surface wave absorbers.

Short-term but not long-term high fat diet feeding protects against pressure overload-induced heart failure through activation of mitophagy

AIMS

Recent studies have shown that enhancement of fatty acid utilization through feeding animals a high fat diet (HFD) attenuated cardiac dysfunction in heart failure (HF). Here, we aimed to examine the temporal effects of HFD feeding on cardiac function in mice with heart failure and its underlying mechanism.

MAIN METHODS

Pressure overload-induced HF was established via transverse aortic constriction (TAC) surgery. After surgery, the mice were fed on either normal diet or HFD for 8 or 16 weeks.

KEY FINDINGS

HFD feeding exerted opposite effects on cardiac function at different time points post-surgery. Short-term HFD feeding (8 wk) protected the heart against pressure overload, inhibiting cardiac hypertrophy and improving cardiac function, while long-term HFD feeding (16 wk) aggravated cardiac dysfunction in TAC mice. Short-term HFD feeding elevated cardiac fatty acid utilization, while long-term HFD feeding showed no significant effects on cardiac fatty acid utilization in TAC mice. Specifically, an increase in cardiac fatty acid utilization was accompanied with activated mitophagy and improved mitochondrial function. Palmitic acid treatment (400 μM, 2 h) stimulated fatty acid oxidation and mitophagy in neonatal myocytes. Mechanistically, fatty acid utilization stimulated mitophagy through upregulation of Parkin. Cardiac-specific knockdown of Parkin abolished the protective effects of short-term HFD feeding on cardiac function in TAC mice.

SIGNIFICANCES

These results suggested that short-term but not long-term HFD feeding protects against pressure overload-induced heart failure through activation of mitophagy, and dietary fat intake should be used with caution in treatment of heart failure.

The impact of delayed heart rate recovery on prevalent hypertension

Objectives: Delayed heart rate recovery (HRR) is considered an indicator of autonomic nervous dysfunction, which is a primary pathological mechanism of hypertension. The present study aimed to explore the independent association between delayed HRR and prevalent hypertension.Methods: In this cross-sectional study, 314 inpatients were recruited between January 2018 and December 2019. HRR was defined as the peak heart rate during exercise minus the 2^nd-minute heart rate after exercise in the treadmill exercise test.Results: The mean HRR in the hypertension group was lower than that in the non-hypertension group (41 bpm vs. 46 bpm; P < 0.001). After full adjustment, each standard deviation increase in HRR was associated with a 35% decrease in the risk of prevalent hypertension (OR: 0.65, 95% CI: 0.48-0.87; P = 0.004). When the HRR was divided into quartiles, the risk in the top quartile was 26% of that in the bottom quartile (OR: 0.26, 95% CI: 0.12-0.56; P = 0.001). Furthermore, smooth curve fitting showed that the risk of prevalent hypertension decreased linearly with the increase in HRR.Conclusion: Delayed HRR was independently associated with prevalent hypertension. The association was linear and robust over the entire range of HRR. The present study suggested that delayed HRR could be used to optimize hypertension risk stratification.

Comparison of clinical diagnostic value of spiral CT with different dose in patients with early-stage peripheral lung cancer

PURPOSE

To compare the clinical diagnostic value of spiral CT scan with different dose in patients with early-stage peripheral lung cancer.

METHODS

A total of 163 cases of patients with early-stage peripheral lung cancer who came to People's Hospital of Rizhao for treatment from June 2014 to January 2017 were retrospectively analyzed. A total of 78 cases of patients who received low-dose CT scanning were the low-dose group, another 84 cases of patients who received routine dose CT scanning were the routine dose group. Multislice helical CT (MSCT) scanning was performed in both groups, with tube voltage of 120 kV. Tube current was 25 m A in the low-dose group and 250 m A in the routine dose group. In addition, a total of 80 patients with lobar pneumonia were added as the control group of diagnostic sensitivity, specificity and accuracy. Pathological diagnosis was taken as the gold standard to compare the diagnostic sensitivity, specificity and accuracy of the two groups.

RESULTS

The image quality, nodules and signs of the two groups were compared, and the results of radiation dose of the two groups were compared. The diagnostic sensitivity, specificity and accuracy of the low-dose group were 82.05%, 87.50% and 84.81%, respectively. The diagnostic sensitivity, specificity and accuracy of the routine dose group were 85.71%, 86.25% and 85.97%, respectively. The diagnostic value of the two groups was not statistically significant (p > 0.05). However, the radiation dose in the low-dose group was significantly lower than that in the routine group.

CONCLUSION

Low-dose MSCT scanning can meet the clinical requirements for imaging diagnosis of peripheral lung cancer, and can reduce the radiation dose of patients.

Common and distinct patterns of gray matter alterations in borderline personality disorder and posttraumatic stress disorder: A dual meta-analysis

BACKGROUND

Borderline personality disorder (BPD) and posttraumatic stress disorder (PTSD) are severe psychiatric disorders and often co-occur, either of the two will seriously threaten to public health. However, we lack ample evidences to understand the potential pathophysiologic mechanisms of gray matter (GM) alterations in the two disorders.

METHODS

We performed a meta-analysis in both BPD (15 datasets including 442 BPD subjects versus 441 healthy controls) and PTSD (11 datasets including 214 PTSD subjects versus 258 healthy controls) applying anisotropic effect-size-based algorithms (AES-SDM) method.

RESULTS

Conjunction analysis found relative GM volume reductions in both disorders in the orbitofrontal gyrus and anterior cingulate cortex, contrarily, differences were predominantly observed that GM volume increased in the posterior cingulate gyrus and precuneus in BPD subjects, and GM volume decreased in the amygdala-hippocampal fear circuit, fusiform gyrus in PTSD subjects.

CONCLUSIONS

Group comparisons and conjunction analyses in BPD and PTSD identified same regions of GM volume reductions in the orbitofrontal gyrus and anterior cingulate cortex, which may provide clues for the neurobiological mechanisms and clinical diagnosis underpinning two disorders.

Fur Represses Vibrio cholerae Biofilm Formation via Direct Regulation of vieSAB, cdgD, vpsU, and vpsA-K Transcription

Attached Vibrio cholerae biofilms are essential for environmental persistence and infectivity. The vps loci (vpsU, vpsA-K, and vpsL-Q) are required for mature biofilm formation and are responsible for the synthesis of exopolysaccharide. Transcription of vps genes is activated by the signaling molecule bis-(3'-5')-cyclic di-GMP (c-di-GMP), whose metabolism is controlled by the proteins containing the GGDEF and/or EAL domains. The ferric uptake regulator (Fur) plays key roles in the transcription of many genes involved in iron metabolism and non-iron functions. However, roles for Fur in Vibrio biofilm production have not been documented. In this study, phenotypic assays demonstrated that Fur, independent of iron, decreases in vivo c-di-GMP levels and inhibits in vitro biofilm formation by Vibrio cholerae. The Fur box-like sequences were detected within the promoter-proximal DNA regions of vpsU, vpsA-K, vieSAB, and cdgD, suggesting that transcription of these genes may be under the direct control of Fur. Indeed, the results of luminescence, quantitative PCR (qPCR), electrophoretic mobility shift assay (EMSA), and DNase I footprinting assays demonstrated Fur to bind to the promoter-proximal DNA regions of vpsU, vpsA-K, and cdgD to repress their transcription. In contrast, Fur activates the transcription of vieSAB in a direct manner. The cdgD and vieSAB encode proteins with GGDEF and EAL domains, respectively. Thus, data presented here highlight a new physiological role for Fur wherein it acts as a repressor of V. cholerae biofilm formation mediated by decreasing the production of exopolysaccharide and the intracellular levels of c-di-GMP.

Adoption of Computerized Tomography Quantitative Imaging Data in the Evaluation of Severe Acute Pancreatitis by Pleural Effusion

In order to study the pleural effusion (PE) in Severe acute pancreatitis (SAP) in patients with the clinical value of diagnosis, in this study, 78 patients with SAP who were included in Shandong Jinan Municipal Hospital of Traditional Chinese Medicine from January 31, 2017 to December 30, 2019 were selected as the experimental group (EG) and 78 patients with mild acute pancreatitis (MAP) as the control group (CG). The PE was diagnosed by computerized tomography (CT) imaging technology, and the patients with PE in the two groups were divided into small group, medium group and large group according to the volume of PE. The concurrent symptoms of SAP were recorded, and the relation between the occurrence of PE and the complications of SAP was analyzed by a multivariate Logistic regression model (LRM). It was concluded that the concurrent rate of PE in the EG was greatly higher than that in the CG, and the number of cases in the medium and multiple groups was also greatly higher than that in the CG (P < 0.05). There were statistically significant differences (SSD) in acute renal failure, hypovolemic shock and pancreatic pseudocyst in the PE small amount group, medium amount group and large amount group (P < 0.05). The complications of SAP in patients with acute renal failure, hypovolemic shock and pancreatic pseudocyst were positively correlated with age and PE (P < 0.05), which showed that CT could present the PE more directly, which was beneficial to the diagnosis of SAP. In addition, the increased amount of PE indicated the aggravation of SAP and the occurrence of concurrent symptoms, which is helpful for early assessment of patients’ condition and prediction of poor prognosis as an independent indicator to evaluate the early stage of SAP.

Direct Binding and Regulation by Fur and HapR of the Intermediate Regulator and Virulence Factor Genes Within the ToxR Virulence Regulon in Vibrio cholerae

Cholera toxin (CT) and toxin coregulated pilus (TCP, TcpA is the major subunit) are two major virulence factors of Vibrio cholerae, both of which play critical roles in developing severe diarrhea in human. Expression of CT and TCP is under the tight control of the regulatory cascade known as the ToxR virulence regulon, which is composed of three regulators ToxR, TcpP, and ToxT. Besides, their expression is also regulated by the quorum sensing (QS) master regulator HapR and the regulatory protein Fur. Though transcription of tcpP, toxT, and/or tcpA are reported to be regulated by HapR and Fur, to date there are no studies to verify their direct regulations. In the present study, we showed that HapR directly repress the transcription of tcpP and tcpA by binding to their promoter regions, and possibly repress toxT transcription in an indirect manner. Fur directly activated the transcription of tcpP, toxT, and tcpA by binding to their promoters. Taking account of the sequential expression of hapR, fur, tcpP, toxT, and tcpA in the different growth phases of V. cholerae, we deduce that at the early mid-logarithmic growth phase, Fur binds to the promoters of tcpP, toxT, and tcpA to activate their transcription; while at the later mid-logarithmic growth phase, HapR can bind to the promoters of tcpP and tcpA to repress their transcription. Our study reveals the new recognition in the virulence regulatory pathways in V. cholerae and suggests the complicated and subtle regulation network with the growth density dependence.

Coronavirus disease 2019: a bibliometric analysis and review

OBJECTIVE

On December 8, 2019, many cases of pneumonia with unknown etiology were first reported in Wuhan, China, subsequently identified as a novel coronavirus infection aroused worldwide concern. As the outbreak is ongoing, more and more researchers focused interest on the COVID-19. Therefore, we retrospectively analyzed the publications about COVID-19 to summarize the research hotspots and make a review, to provide reference for researchers in the world.

MATERIALS AND METHODS

We conducted a search in PubMed using the keywords "COVID-19" from inception to March 1, 2020. Identified and analyzed the data included title, corresponding author, language, publication time, publication type, research focus.

RESULTS

183 publications published from 2020 January 14 to 2020 February 29 were included in the study. The first corresponding authors of the publications were from 20 different countries. Among them, 78 (42.6%) from the hospital, 64 (35%) from the university and 39 (21.3%) from the research institution. All the publications were published in 80 different journals. Journal of Medical Virology published most of them (n=25). 60 (32.8%) were original research, 29 (15.8%) were review, 20 (10.9%) were short communications. 68 (37.2%) epidemiology, 49 (26.8%) virology and 26 (14.2%) clinical features.

CONCLUSIONS

According to our review, China has provided a large number of research data for various research fields, during the outbreak of COVID-19. Most of the findings play an important role in preventing and controlling the epidemic around the world. With research on the COVID-19 still booming, new vaccine and effective medicine for COVID-19 will be expected to come out in the near future with the joint efforts of researchers worldwide.

Clinical characteristics of older patients infected with COVID-19: A descriptive study

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The number of COVID-19 cases surpassed 300,000, WHO identified as a global pandemic.

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COVID-19 has been a serious threat to old population.

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The COVID-19 infection is generally susceptible with a relatively high fatality rate in older patients.

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More attention should pay to the elderly patients with COVID-19 infection.

Objectives

Since the outbreak of 2019 novel coronavirus (COVID-19), which has spread in the world rapidly. Population have a susceptibility to COVID-19, older people were more susceptible to have a variety diseases than younger, including COVID-19 infection with no doubt. This study focused on older patients with COVID-19 infection and analyzed the epidemiological and clinical characteristics of them.

Methods

We collected information on confirmed older patient transferred by Beijing Emergency Medical Service (EMS) to the designated hospitals from Jan 20 to Feb 29, 2020. The information including demographic, epidemiological, clinical, classification of severity and outcomes. All cases were categorized into three groups and compared the difference between aged 50–64 years, 65–79 years and older than 80 years.

Results

56.7 % of elderly confirmed patients were male, fever (78.3 %), cough (56.7 %), dyspnea (30.0 %), and fatigue (23.3 %) were common symptoms of COVID-19 infection. Classification of severity has statistically significant differences between the three groups, compared with middle-aged patients and aged 65–79 years group, older than 80 years group had significant statistical differences in contacted to symptomatic case in 14 days. As of Feb 29, 38.3 % patients had discharged and 53.3 % patients remained in hospital in our study, the fatality of COVID-19 infection in elderly was 8.3 %.

Conclusions

The COVID-19 infection is generally susceptible with a relatively high fatality rate in older patients, we should pay more attention to the elderly patients with COVID-19 infection.

Characteristics of COVID-19 infection in Beijing

BACKGROUND

Since the first case of a novel coronavirus (COVID-19) infection pneumonia was detected in Wuhan, China, a series of confirmed cases of the COVID-19 were found in Beijing. We analyzed the data of 262 confirmed cases to determine the clinical and epidemiological characteristics of COVID-19 in Beijing.

METHODS

We collected patients who were transferred by Beijing Emergency Medical Service to the designated hospitals. The information on demographic, epidemiological, clinical, laboratory test for the COVID-19 virus, diagnostic classification, cluster case and outcome were obtained. Furthermore we compared the characteristics between severe and common confirmed cases which including mild cases, no-pneumonia cases and asymptomatic cases, and we also compared the features between COVID-19 and 2003 SARS.

FINDINGS

By Feb 10, 2020, 262 patients were transferred from the hospitals across Beijing to the designated hospitals for special treatment of the COVID-19 infected by Beijing emergency medical service. Among of 262 patients, 46 (17.6%) were severe cases, 216 (82.4%) were common cases, which including 192 (73.3%) mild cases, 11(4.2%) non-pneumonia cases and 13 (5.0%) asymptomatic cases respectively. The median age of patients was 47.5 years old and 48.5% were male. 192 (73.3%) patients were residents of Beijing, 50 (26.0%) of which had been to Wuhan, 116 (60.4%) had close contact with confirmed cases, 21 (10.9%) had no contact history. The most common symptoms at the onset of illness were fever (82.1%), cough (45.8%), fatigue (26.3%), dyspnea (6.9%) and headache (6.5%). The median incubation period was 6.7 days, the interval time from between illness onset and seeing a doctor was 4.5 days. As of Feb 10, 17.2% patients have discharged and 81.7% patients remain in hospital in our study, the fatality of COVID-19 infection in Beijing was 0.9%.

INTERPRETATION

On the basis of this study, we provided the ratio of the COVID-19 infection on the severe cases to the mild, asymptomatic and non-pneumonia cases in Beijing. Population was generally susceptible, and with a relatively low fatality rate. The measures to prevent transmission was very successful at early stage, the next steps on the COVID-19 infection should be focused on early isolation of patients and quarantine for close contacts in families and communities in Beijing.

FUNDING

Beijing Municipal Science and Technology Commission and Ministry of Science and Technology.

Characteristics of COVID-19 infection in Beijing

BACKGROUND

Since the first case of a novel coronavirus (COVID-19) infection pneumonia was detected in Wuhan, China, a series of confirmed cases of the COVID-19 were found in Beijing. We analyzed the data of 262 confirmed cases to determine the clinical and epidemiological characteristics of COVID-19 in Beijing.

METHODS

We collected patients who were transferred by Beijing Emergency Medical Service to the designated hospitals. The information on demographic, epidemiological, clinical, laboratory test for the COVID-19 virus, diagnostic classification, cluster case and outcome were obtained. Furthermore we compared the characteristics between severe and common confirmed cases which including mild cases, no-pneumonia cases and asymptomatic cases, and we also compared the features between COVID-19 and 2003 SARS.

FINDINGS

By Feb 10, 2020, 262 patients were transferred from the hospitals across Beijing to the designated hospitals for special treatment of the COVID-19 infected by Beijing emergency medical service. Among of 262 patients, 46 (17.6%) were severe cases, 216 (82.4%) were common cases, which including 192 (73.3%) mild cases, 11(4.2%) non-pneumonia cases and 13 (5.0%) asymptomatic cases respectively. The median age of patients was 47.5 years old and 48.5% were male. 192 (73.3%) patients were residents of Beijing, 50 (26.0%) of which had been to Wuhan, 116 (60.4%) had close contact with confirmed cases, 21 (10.9%) had no contact history. The most common symptoms at the onset of illness were fever (82.1%), cough (45.8%), fatigue (26.3%), dyspnea (6.9%) and headache (6.5%). The median incubation period was 6.7 days, the interval time from between illness onset and seeing a doctor was 4.5 days. As of Feb 10, 17.2% patients have discharged and 81.7% patients remain in hospital in our study, the fatality of COVID-19 infection in Beijing was 0.9%.

INTERPRETATION

On the basis of this study, we provided the ratio of the COVID-19 infection on the severe cases to the mild, asymptomatic and non-pneumonia cases in Beijing. Population was generally susceptible, and with a relatively low fatality rate. The measures to prevent transmission was very successful at early stage, the next steps on the COVID-19 infection should be focused on early isolation of patients and quarantine for close contacts in families and communities in Beijing.

FUNDING

Beijing Municipal Science and Technology Commission and Ministry of Science and Technology.