A morphological study of the foveal avascular zone in patients with diabetes mellitus using optical coherence tomography angiography.

PURPOSE: To investigate the area and radius of the foveal avascular zone (FAZ) in patients with diabetes mellitus (DM) using optical coherence tomography (OCT) angiography. METHODS: Sixty-five patients with DM (113 eyes) and 62 healthy controls (85 eyes) were included in the study. All of the participants underwent examination with OCT angiography. The vertical radius (VR), horizontal radius (HR) and area of the FAZ were measured. RESULTS: The differences in HR, VR and area between the control and DM groups were statistically significant (p = 0.01, 0.00 and 0.00, respectively). There were no statistically significant differences between the control group and the no-diabetic retinopathy (DR) group in HR or VR (p = 0.07 and 0.08, respectively), but there was a statistically significant difference in area (p = 0.04). The size of the FAZ was greater in patients with DR compared to the control group. The differences in HR, VR and area were statistically significant (p = 0.01, 0.00 and 0.00, respectively). In addition, the clinically significant macular oedema (CSME) group also had a larger FAZ area than the non-CSME group (p = 0.02). CONCLUSIONS: Patients with DM had a larger FAZ, and patients with more severely damaged retinas had a much larger FAZ. OCT angiography is a new convenient and noninvasive method for studying the FAZ. This novel examination will yield considerable amounts of data that cannot be obtained using previous research methods.

Practice of video-assisted teaching ward rounds for typical cases of ophthalmology / 基础医学与临床

Objective To investigate the efficacy of video-assisted teaching ward rounds for typical cases of oph-thalmology in clinical practice for medical undergraduates.Methods A total of 45 students from clinical medicine in Peking Union Medical College were enrolled.They were randomly divided into the experimental group(23 students)and control group(22 students).Primary angle closure glaucoma(PACG)was selected as the learning content,the experimental group was trained by video-assisted teaching ward rounds,while the control group was trained by internship in outpatient clinic.All students joined the test of typical case PACG and a ques-tionnaire survey was implemented for the experimental group.Results The average score of experimental group was higher than control group[(84.30±4.53)vs.(78.05±5.76),t＝4.05,P＜0.001].For video-assisted teaching ward rounds,in experimental group,86.9%(20/23)students believed it was more practical,95.6%(22/23)students thought it was very helpful and 91.3%(21/23)students considered it was conductive to im-prove interest of learning and clinical thinking ability.Conclusions Video-assisted teaching ward rounds improves students'understanding memory of ophthalmic typical cases,which is a potential supplement teaching method in clinical practice training of ophthalmology for medical undergraduates.

Epidemiological characteristics of a 2019-nCoV outbreak caused by Omicron variant BF.7 in Shenzhen / 中华流行病学杂志

Objective: To explore the epidemiological characteristic of a COVID-19 outbreak caused by 2019-nCoV Omicron variant BF.7 and other provinces imported in Shenzhen and analyze transmission chains and characteristics. Methods: Field epidemiological survey was conducted to identify the transmission chain, analyze the generation relationship among the cases. The 2019-nCoV nucleic acid positive samples were used for gene sequencing. Results: From 8 to 23 October, 2022, a total of 196 cases of COVID-19 were reported in Shenzhen, all the cases had epidemiological links. In the cases, 100 were men and 96 were women, with a median of age, M (Q1, Q3) was 33(25, 46) years. The outbreak was caused by traverlers initial cases infected with 2019-nCoV who returned to Shenzhen after traveling outside of Guangdong Province.There were four transmission chains, including the transmission in place of residence and neighbourhood, affecting 8 persons, transmission in social activity in the evening on 7 October, affecting 65 persons, transmission in work place on 8 October, affecting 48 persons, and transmission in a building near the work place, affecting 74 persons. The median of the incubation period of the infection, M (Q1, Q3) was 1.44 (1.11, 2.17) days. The incubation period of indoor exposure less than that of the outdoor exposure, M (Q1, Q3) was 1.38 (1.06, 1.84) and 1.95 (1.22, 2.99) days, respcetively (Wald χ2=10.27, P=0.001). With the increase of case generation, the number and probability of gene mutation increased. In the same transmission chain, the proportion of having 1-3 mutation sites was high in the cases in the first generation. Conclusions: The transmission chains were clear in this epidemic. The incubation period of Omicron variant BF.7 infection was shorter, the transmission speed was faster, and the gene mutation rate was higher. It is necessary to conduct prompt response and strict disease control when epidemic occurs.

Factors associated with positive results in English literature of acupuncture for chronic pain / 中国针灸

OBJECTIVE@#To analyze the main factors affecting the positive results of acupuncture for chronic pain in English literature of randomized controlled trial (RCT), in order to provide reference for the design of acupuncture clinical research.@*METHODS@#The RCTs of acupuncture for chronic pain published before March 26, 2020 were searched in PubMed, EMbase and Cochrane Library by computer. A total of 21 factors were analyzed by single-factor analysis, and the factors with statistically significant difference were selected for multivariate Logistic regression analysis.@*RESULTS@#A total of 69 RCTs were included, including 47 RCTs (68.12%) with positive results and 22 RCTs (31.88%) with non-positive results. The multivariate Logistic regression analysis was performed with the three screened factors (publication year, treatment frequency and intervention form) selected by single-factor analysis, and the results showed that the positive results were related to the frequency of acupuncture treatment. The positive rate of RCT with frequency≥2 times a week was 3.24 times of that with frequency<2 times a week (OR=3.24, 95%CI =[1.07,9.83], P<0.05).@*CONCLUSION@#Acupuncture frequency may be the main factor affecting the positive results of RCT in English literature of acupuncture for chronic pain. More researches are needed in the future to explore the influence of acupuncture frequency on the curative effect.

The value of CT angiography in risk factor assessment of intracranial aneurysm rupture / 中国医师杂志

Objective:To evaluate the value of CT angiography (CTA) in the assessment of risk factors for rupture of intracranial aneurysm (IA).Methods:The clinical and CT imaging data of 46 patients with IA in the Second Affiliated Hospital of Bengbu Medical College from January 2018 to June 2020 were retrospectively analyzed. The morphological parameters of aneurysm were analyzed by CTA post-processing images: aneurysm number, site, morphology, maximum diameter, height/neck width, maximum diameter/parent artery proximal diameter, aneurysm incidence angle. The morphological risk factors of aneurysm rupture were evaluated by univariate analysis and multivariate logistic regression analysis. We used receiver operating characteristics curve (ROC) to evaluate the diagnostic efficacy in predicting aneurysm rupture.Results:A total of 58 aneurysms were detected by CTA, 30 ruptured aneurysms and 28 unruptured aneurysms. There was no statistically significant difference in gender and age between patients with ruptured and unruptured aneurysms ( P>0.05). In the morphological parameters of ruptured and unruptured aneurysms, there were no statistically significant differences in the number, site and height/neck width of aneurysms ( P>0.05), while there were statistically significant differences in aneurysm morphology, maximum diameter, maximum diameter/parent artery proximal diameter and aneurysm incidence angle ( P<0.05). Multivariate logistic regression analysis showed that maximum diameter/parent artery proximal diameter and aneurysm incidence angle were independent risk factors for aneurysm rupture ( P<0.05). ROC curve analysis showed that when the maximum diameter of the tumor / the diameter of the proximal carrying artery >1.985, the area under the curve was 0.748, and the sensitivity and specificity were 76.7% and 64.3%, respectively; When the incidence angle of blood flow was >117.5°, the area under the curve was 0.673, and the sensitivity and specificity were 53.3% and 75.0% respectively. Conclusions:The maximum diameter/parent artery proximal diameter >1.985 and the aneurysm incidence angle >117.5° are independent risk factors for aneurysm rupture.

Optimization and implementation of clinical trial of acupuncture: reflection on the successful case of acupuncture for postprandial distress syndrome / 中国针灸

Taking the clinical trial of acupuncture in treatment of postprandial distress syndrome as an example, this paper proposes that the acupuncture clinical trial protocol should be optimized in view of acupuncture prescription, acupuncture frequency and outcomes. Besides, the data quality of acupuncture clinical trial should be improved in consideration of data sharing and electronic data capture so as to provide a reference for the majority of researchers to optimize and implement acupuncture clinical trial.

Reporting quality of RCTs of acupuncture for vascular dementia / 中国针灸

OBJECTIVE@#To evaluate the reporting quality of randomized controlled trials (RCTs) of acupuncture for vascular dementia.@*METHODS@#The RCTs of acupuncture for vascular dementia were systematically retrieved from the Cochrane Library, PubMed, EMbase, CNKI, SinoMed, VIP and Wanfang databases from the date of establishment to October 31, 2018. The reporting quality of RCT was evaluated based on the internationally-recognized Consolidated Standards for Reporting of Trials (CONSORT) statement and Standards for Reporting Interventions in Controlled Trials of Acupuncture (STRICTA).@*RESULTS@#A total of 33 RCTs were included. According to the CONSORT statement, 12 items had a reporting rate of 0%, including important changes to methods after trial commencement, sample size, blind method, trial registry, etc.; 5 items had a reporting rate of below 10%, including trial design, type of randomization, random allocation sequence, randomization implementation and participant flow. The reporting rate was 36.36% for baseline data and 57.58% for randomization sequence generation. According to the STRICTA statement, the reporting rate was 21.21% for description of acupuncture depth, 60.61% for description of acupuncture response, 27.27% for description of additional intervention details and 0% for qualification of acupuncturists, respectively.@*CONCLUSION@#At present, the reporting quality of RCTs of acupuncture for vascular dementia is generally low. In the future, the RCTs of acupuncture for vascular dementia should be normatively reported according to the CONSORT statement and STRICTA statement.

A three-microRNA panel in serum as novel biomarker for papillary thyroid carcinoma diagnosis / 中华医学杂志(英文版)

BACKGROUND@#Accumulating evidence has revealed that circulating microRNAs (miRNAs) can serve as non-invasive biomarkers for cancer diagnosis. This study aimed to identify differentially expressed miRNAs in serum which might become potential biomarkers for non-invasive diagnosis of papillary thyroid carcinoma (PTC).@*METHODS@#The experiment was carried out between 2015 and 2017. In the screening stage, the Exiqon miRNA quantitative real-time polymerase chain reaction (qPCR) panel was applied to select candidate miRNAs. In the following training, testing, and external validation stages, the serum samples of 100 patients and 96 healthy controls (HCs) were analyzed to compare the expression levels of the identified miRNAs. The areas under the receiver operating characteristic curves (AUCs) were calculated to assess the diagnostic value of the identified signature.@*RESULTS@#Three miRNAs (miR-25-3p, miR-296-5p, and miR-92a-3p) in serum were consistently up-regulated in PTC patients compared with HCs. A three-miRNA panel was constructed by logistic regression analysis and showed better diagnostic performance than a single miRNA for PTC detection. The AUCs of the panel were 0.727, 0.771, and 0.862 for the training, testing, and external validation stage, respectively. Meanwhile, the panel showed stable capability in differentiating PTC patients from patients with benign goiters, with an AUC as high as 0.969. For further exploration, the three identified miRNAs were analyzed in tissue samples (23 PTC vs. 23 HCs) and serum-derived exosomes samples (24 PTC vs. 24 HCs), and the altered expression in the tumor also indicated their close relationship with PTC disease.@*CONCLUSION@#We identify a three-miRNA panel in serum which might serve as a promising biomarker for PTC diagnosis.

Recent advances in enzyme inhibitor screening based on mass spectrometry / 药学学报

Enzymes play crucial functional roles in all biological processes. Enzymatic inhibitors can regulate enzyme activity and may become the starting point for drug discovery. Mass spectrometry (MS) has the advantage for rapid qualitative and quantitative analyses of compounds and enzyme reactions, emerging as an important analytical tool in enzyme inhibitor screening assay for drug discovery. This review will highlight recent advances in the inhibitor screening assay using MS and related techniques, including frontier affinity chromatography, immobilized enzyme beads, ultrafiltration, surface plasmon resonance, capillary electrophoresis and microfluidic chips. The existing MS methods for screening enzyme inhibitor were divided into two types: affinity screening and activity screening.

Researches status on time-effect of acupuncture / 中国针灸

OBJECTIVE@#To summarize the research status and influencing factors of the time-effect of acupuncture and to explain and analyze the optimal effect timing of acupuncture, and provide reference for obtaining the best clinical therapeutic effect.@*METHODS@#Literature regarding the studies of the time-effect of acupuncture published from January 2000 to August 2018 was searched, concluded and analyzed in CNKI, WANFANG, VIP and PubMed databases.@*RESULTS@#A total of 43 papers were included. The time-effect relationship of acupuncture was studied from various aspects: immediate effect, post-effect and total time-effect. The influencing factors of time-effect of acupuncture included needle retention time, acupoint types, number of acupoints and frequency of acupuncture treatment.@*CONCLUSION@#Even though preliminary achievements have been made in the study of the time-effect of acupuncture, there are many limitations and deficiency. These studies are mostly isolated and unsystematic, and the observation time of needle retention time and post-effect is not long enough to observe the exact best induction period, half-life period and residual effect period of acupuncture.In the future, we should combine the existing research experience and achievements to formulate a more reasonable research plan and observe the entire period of acupuncture in a longitudinal direction.

Clinical features of cancer-associated retinopathy / 中华实验眼科杂志

Objective To analyze the clinical features of cancer-associated retinopathy (CAR).Methods The clinical data of 10 patients who diagnosed as CAR during 5 years were retrospectively analyzed.All patients underwent detailed ocular examinations,including electroretinogram (ERG),optical coherence tomography (OCT),visual field (VF) and autofluorescence(AF).Results The primary malignancy was lung carcinoma in 3 patients,thymoma in 3 patients,thyroid carcinoma in 1 patients,maxillary sinus tumor in 1 patients,nasopharyngeal carcinoma in 1 patients and rectal cancer in 1 patients.All patients complained progressive visual reducing.Three patients manifested night blindness.The best corrected visual acuity (BCVA)＜0.1 was in three eyes,≤0.1-＜0.5 in seven eyes,and ≥0.5 in ten eyes.Patients showed normal fundi or mild abnormality.OCT images showed disorganization and/or loss of the ellipsoid zone in the macular area in 4 patients,and other six patients had only central foveal ellipsoid zone preserved.Eight patients had moderately or severely reduced ffERG,and 2 patients demonstrated electro-negative ERG.Five patients revealed peripheral visual defect.AF images were from normal to low or high AF patches in the posterior pole and mid-peripheral retina.Conclusions The clinical manifestations of CAR are varied as common characteristics of progressive visual decrease with or without night blindness,visual field defect and abnormal ffERG recording.

Imaging features and main clinical manifestations of patients with respiratory and/or cardiac arrest in medullary infarction:A single center retrospective study / 中风与神经疾病杂志

@#Objective　To investigate the imaging characteristics and main clinical manifestations of patients with respiratory and/or cardiac arrest after medullary infarction (MI).Methods　The study included patients with respiratory and/or cardiac arrest after MI,who were hospitalized in the Department of Neurology of Huanhu hospital between 2016 and 2021.The patients were divided into groups and analyzed according to the infarct location and infarct size shown by MRI-DWI,the degree of vascular stenosis shown by MRA and the main clinical manifestations.Results　The study enrolled a total of 28 patients, including 19 patients with lateral medullary infarction (LMI) and 9 patients with medial medullary infarction (MMI).For LMI patients,from head to tail,there were 4 cases with upper MI,11 cases with middle MI,and 4 cases with lower MI.On the axial plane,there were 4 cases in the middle,14 cases in the dorsal,and 1 case through the middle and dorsal.Among the 28 patients,50% were large area MI (DWI high signal≥1/3 of the total area of medulla oblongata) and medium area MI (1/4 of the total area of medulla oblongata≤DWI high signal<1/3 of the total area of medulla oblongata).Sixteen cases completed brain MRA examination,of which 12 cases were moderate and severe vascular stenosis.Among the 28 patients,16 cases were complicated with infarction in other parts,of which 9 cases were complicated with cerebellar infarction.The main clinical symptoms were dizziness and dysarthria.For the 19 LMI patients,dizziness was the main complaint in 16,dysarthria in 16,dysphagia in 10,limb weakness in 7.For the 9 MMI patients,dizziness was the main complaint in 6,dysarthria in 8,dysphagia in 3,limb weakness in 7.Conclusion　LMI is the main type of respiratory and/or cardiac arrest after MI,and it is more common in patients with dorsal medulla oblongata in the middle part.The proportion of patients with medium and large area MI is relatively high.Most patients have moderate and severe vascular stenosis and often complicated with cerebellar infarction.The main complaints were dizziness and dysarthria.LMI was more prone to dysphagia and MMI to limb weakness.

Outcomes of ischemic stroke patients with atrial fibrillation / 中华神经医学杂志

Objective To assess the outcomes of ischemic stroke patients with atrial fibrillation (AF).Methods Six thousand six hundred and ninety-five patients with acute ischemic stroke,admitted to our hospital from May 2005 to December 2013,were recruited consecutively.These patients were divided into combined AF group (n=583) and non-combined AF group (n=6112).The clinical data,including stroke subtypes,stroke severity,risk factors of stroke,NIHSS scores and Barthel index,and outcomes,including mortality,unfavourable prognosis and recurrence at 3,12,and 36 months after stroke were analyzed.Results The prevalence rate of AF in the patients enrolled in this study was 8.7％ (583/6695).There was a higher frequency of AF in female than that in male,with significant difference (45.8％ vs.33.0％,P＜0.05).The patients from combined AF group were older than those without AF.The percentage of severe stroke in AF patients (34.8％) was significantly higher than that in non-combined AF group (8.3％,P＜0.05).The patients with AF were less likely than the patients without AF to have hypertension (63.8％ vs.73.3％),diabetes (24.9％ vs.32.3％),dyslipidemias (26.1％ vs.31.5％),artery stenosis (17.2％ vs.23.4％),current smoking (22.6％ vs.39.0％),and alcohol consumption (7.5 ％ vs.18.9％),with significant differences (P＜0.05).After adjusting age,gender,stroke subtype,and severity,and risk factors,multivariate analysis showed that there was a higher recurrence risk in combined AF group at 3 months after stroke than that in non-combined AF group (P＜0.05);patients with AF had significantly higher mortality,dependency,and recurrence rates at 12 and 36 months after stroke than those without AF (P＜0.05).Conclusion The long-term prognosis of patients with stroke complicated with AF is poor;therefore,normalized anticoagulant therapy should be taken to decrease the recurrence rate and burdens of stroke in China.

Proteomics analysis of distinct proteins in carotid atherosclerotic plaques / 中风与神经疾病杂志

@#Objective　We used proteomics technologies in an attempt to differentiate and identify histological proteins that were associated with carotid atherosclerotic plaques and further understanding of the pathogenesis. Methods　Carotid atherosclerotic plaques were obtained from the patients who undergo carotid endarterectomy in the Tianjin Huanhu Hospital. Plaques divided into two groups：stable group and unstable group. We comparatively analyzed the proteome of 10 unstable plaques and 10 stable plaques. The differentially expressed proteins were visualized by two dimensional electrophoresis（2DE）and were analyzed by a coupled label-free and mass spectrometry approach. The protein identification program was used to search the Uniprot. Results　A total of 1240 different proteins were identified by label-free and mass spectrometry. A total of 808 proteins were upregulated，and 432 proteins were downregulated in unstable plaques group compared to stable plaques group. They are referring to signal transduction，lipid transport and metabolism，posttranslational modification，cytoskeleton and Proteolysis. Conclusion　Proteomics analysis can be used to investigated differentially expressed proteins. However，Additional confirmatory studies are required to elucidated their role in the atherosclerotic process.

Sequential bilateral central retinal artery occlusion as the primary manifestation of systemic lupus erythematosus / 中华医学杂志(英文版)

Bilateral central retinal artery occlusion (CRAO) has been rarely reported as the primary manifestation in patients with systemic lupus erythematosus (SLE). The severe retinal vaso-occlusive diseases usually cause devastating and permanent damage to visual function in spite of vigorous treatment. A 42-year-old Chinese woman presented with abrupt bilateral vision loss. The diagnosis of bilateral CRAO was suggested by the ocular presentation and fluorescein angiography. Laboratory studies showed positive results of antinuclear antibody, anti-Ro/SSA anti-La/SSB; decreased levels of C3, C4 complement and normal levels of antiphospholipides antibodies (APAs). Her visual acuity deteriorated despite systemic steroid and immunosuppressant treatment. Severe vaso-occlusive retinopathy may be an earlier manifestation of SLE without elevated level of APAs.

Spectral-domain OCT features of macular edema induced by central retinal vein occlusion / 中华实验眼科杂志

Background Cystoid macular edema(CME) is an important cause of visual impairment of central retinal vein occlusion(CRVO).Spectral-Domain optical coherence tomography(SD-OCT) has increased speed and higher resolution,offering a better chance of understanding the morphological changes and pathogenesis of CME. Objective This study was to survey the morphologic features of macular edema associated with CRVO by SD-OCT. Methods Clinical data of the patients with CRVO diagnosed in Department of Ophthalmology,Peking Union Medical College Hospital from March 2008 to August 2009 were retrospectively analyzed.SD-OCT features of macular edema induced by CRVO were analyzed and recorded.Results The average macular foveal thickness was(527.5±218.2) μm in macular edemas eyes.Main morphological changes included 55 cases(84.6%) of CME,15 cases of(23.1%) serous macular detachment(SMD),and 10 cases(15.4%) of simple macular edema,and these findings occurred at the same time in some eyes.Cystoid spaces in the parafoveal region were seen in the inner nuclear layer,outer plexiform layer and outer nuclear layer,and discontinuous or weak inner segment/outer segment(IS/OS) line was often seen in CME.The incidence of CME associated with incomplete posterior vitreous detachment(PVD) was 14.5%,and that of neural epithelial edema associated with incomplete PVD was 10.0%,showing an insignificant difference between them(χ2=0.000,P=1.000).The average area of SMD was 1838.4μm ×1428.1μm×190.1μm,and the incidence of partial PVD was higher(χ2=4.266,P=0.039).Conclusion SD-OCT can reveal the micro-morphological change of macular zone in macular edema eye.SD-OCT enabled visualization of its spatial extent in each retinal layer and the condition of IS/OS layer.Serous macular edema is related with partial PVD.

A community-based study on relations between metabolic syndrome and carotid atherosclerosis in a middle-aged population / 中华流行病学杂志

Objective To explore the association between metabolic syndromes (MS) and carotid atherosclerosis and to estimate the predictive effects of MS under 3 different definitions.Methods A cross-sectional study was conducted in 2 community-based populations in Beijing,in 2008.1266 subjects (598 men,668 women),aged 45-69,were included in the analyses.MS was defined by the criteria of International Diabetes Federation (IDF),the revised NCEPATPm (ATP Ⅲ-R) and "The Guidelines of Dyslipidemia Control for Chinese Adult" ( "Guidelines" ) in 2007.Results The prevalence rates of MS by the 3 criteria were 39.0%,43.3% and 30.9% respectively.The Kappa value for the measure of the agreement between each pair of the 3 definitions were 0.911,0.719 and 0.730 respectively.The intima-media thickness in common carotid artery (CCA-IMT) was significantly higher (P＜0.001) in all MS groups than in non-MS groups,diagnosed with the 3 criteria independent of age,gender,LDL-C,and current smoking status.After adjustment of age,gender,LDL-C,and current smoking status,the classification of MS significantly increased the risk of prevalence of carotid atberosclerotic plaques,compared to the non-MS group.OR value were 1.499 (95% CI:1.157-1.942) for IDF,1.696 (95% CI:1.314-2.189) for NCEP-R,1.763 (95% CI:1.344-2.312) for "Guideline" respectively.Conclusion Our research findings indicated that,when MS were defined with the 3 definitions,prediction on the risk of sub-clinical atberosclerosis would work beyond some of the conventional cardiovascular risk factors such as smoking,LDL-C.There might exist some differences in gender issue on the strength of association between MS when diagnosed by different criteria and carotid plaque.

Keratorefractive surgery and glaucoma / 国际眼科杂志(Guoji Yanke Zazhi)

Keratorefractive surgery changes the central corneal thickness (CCT) and corneal curvature, which could influence the Goldmann applanation tonometer (GAT) and non-contact tonometer (NCT) measurements of intraocular pressure (IOP), but not dynamic contour tonometer(DCT). During the procedure of LASIK, there is a transient rise of IOP, which increases the risks of optic nerve damage. Meanwhile, the presence of functioning filtering blebs may affect the choice and outcome of refractive surgery, or even becomes a contraindication of surgery. Steroids are typically used after keratorefractive surgery, which could lead to IOP elevation. Hence it is important to monitor IOP after LASIK and to be aware of inaccurate IOP readings due to corneal flap interface fluid. Treating patients with postoperative elevated IOP after keratorefractive surgery is similar to that for patients with glaucoma. This review will address the issues surrounding the safety, relevant complications and implications of keratorefractive surgeries on glaucoma and relevant diagnostic tests.

Epidemiological and clinical characteristics of COVID-19 in Shenzhen, the largest migrant city of China

We conducted a retrospective study among 417 confirmed COVID-19 cases from Jan 1 to Feb 28, 2020 in Shenzhen, the largest migrant city of China, to identify the epidemiological and clinical features in settings of high population mobility. We estimated the median incubation time to be 5.0 days. 342 (82.0%) cases were imported, 161 (38.6%) cases were identified by surveillance, and 247 (59.2%) cases were reported from cluster events. The main symptoms on admission were fever and dry cough. Most patients (91.4%) had mild or moderate illnesses. Age of 50 years or older, breathing problems, diarrhea, and longer time between the first medical visit and admission were associated with higher level of clinical severity. Surveillance-identified cases were much less likely to progress to severe illness. Although the COVID-19 epidemic has been contained in Shenzhen, close monitoring and risk assessments are imperative for prevention and control of COVID-19 in future. Article Summary LineWe characterized epidemiological and clinical features of a large population-based sample of COVID-19 cases in the largest migrant city of China, and our findings could provide knowledge of SARS-CoV-2 transmission in the context of comprehensive containment and mitigation efforts in similar settings.

Insights into the practical effectiveness of RT-PCR testing for SARS-CoV-2 from serologic data, a cohort study

BackgroundVirologic detection of SARS-CoV-2 through Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) has limitations for surveillance. Serologic tests can be an important complementary approach. ObjectiveAssess the practical performance of RT-PCR based surveillance protocols, and the extent of undetected SARS-CoV-2 transmission in Shenzhen, China. DesignCohort study nested in a public health response. SettingShenzhen, China; January-May 2020. Participants880 PCR-negative close-contacts of confirmed COVID-19 cases and 400 residents without known exposure (main analysis). Fifty-seven PCR-positive case contacts (timing analysis). MeasurementsVirological testing by RT-PCR. Measurement of anti-SARS-CoV-2 antibodies in PCR-negative contacts 2-15 weeks after initial testing using total Ab ELISA. Rates of undetected infection, performance of RT-PCR over the course of infection, and characteristics of seropositive but PCR-negative individuals were assessed. ResultsThe adjusted seropositivity rate for total Ab among 880 PCR-negative close-contacts was 4.1% (95%CI, 2.9% to 5.7%), significantly higher than among residents without known exposure to cases (0.0%, 95%CI, 0.0% to 1.0%). PCR-positive cases were 8.0 times (RR; 95% CI, 5.3 to 12.7) more likely to report symptoms than the PCR-negative individuals who were seropositive, but otherwise similar. RT-PCR missed 36% (95%CI, 28% to 44%) of infected close-contacts, and false negative rates appear to be highly dependent on stage of infection. LimitationsNo serological data were available on PCR-positive cases. Sample size was limited, and only 20% of PCR-negative contacts met inclusion criteria. ConclusionEven rigorous RT-PCR testing protocols may miss a significant proportion of infections, perhaps in part due to difficulties timing testing of asymptomatics for optimal sensitivity. Surveillance and control protocols relying on RT-PCR were, nevertheless, able to contain community spread in Shenzhen. Funding sourceBill & Melinda Gates Foundation, Special Foundation of Science and Technology Innovation Strategy of Guangdong Province of China, and Key Project of Shenzhen Science and Technology Innovation Commission, Shenzhen, China