While effectiveness of monovalent inactivated SARS-CoV-2 vaccines on preventing infection and severe disease has been well-characterized, their effectiveness on reducing infectivity of infected individuals and thereby blocking onward transmission to close contacts remains poorly understood. Leveraging contact-tracing data obtained during the Delta outbreaks in Guangzhou (May–June 2021) and Yangzhou (July–August 2021), as well as the Omicron outbreak in Guangzhou (April 2022), we used individual-based Bayesian transmission models to estimate vaccine effectiveness on reducing susceptibility (VES) and infectivity (VEI) across various contact settings, adjusting for tertiary transmission, case importation, and exposure history. Results: Based on 323 primary cases and 53,895 close contacts, we find no evidence for VES (comparing 0, 1, and ≥2 doses) but significant VEI (comparing ≤1 vs. ≥2 doses) against both Delta and Omicron variants. Compared to ≤1 dose of inactivated monovalent vaccines, ≥2 doses are associated with 45% (95% Credible Interval [CrI]: 15%, 66%) lower infectivity for the Delta variant and 54% (95% CrI: 34%–80%) for the Omicron variant respectively. Household and entertainment are associated with the highest baseline transmission risks. The most susceptible age group is older adults (60+ years) during the Delta outbreaks but children (0–19 years) during the Omicron outbreak. First-generation monovalent inactivated vaccines offer sustainable community-level protection against novel variants by reducing infectivity of infected individuals, representing a critical but understudied component of the herd immunity. Inactivated COVID-19 vaccines are known to prevent severe disease, but their ability to reduce how contagious infected people are remains poorly understood. Using detailed contact-tracing data from Delta and Omicron outbreaks in Guangzhou and Yangzhou, China (2021-2022), we used statistical models to estimate vaccine effects on both susceptibility to infection and infectivity of infected individuals. We found that while inactivated vaccines provided minimal protection against getting infected, they substantially reduced onward transmission by 45% for Delta and 54% for Omicron among individuals with two or more doses. Households and entertainment showed the highest transmission risk. These findings indicate that first-generation inactivated vaccines can suppress community transmission by reducing how infectious vaccinated cases are. Tsang, Jing, et al. use individual-based Bayesian transmission models with contact-tracing data from Delta and Omicron outbreaks in China. They find that first-generation monovalent inactivated vaccines provide minimal protection against infection but reduce onward transmission by 45-54%.

Urothelial carcinomas (UCs) are the fourth most common male malignancies. However, currently implemented detection methods for UC are usually invasive and/or show passable sensitivity and specificity. An accurate, practical, and effective approach is urgently needed for UC clinical detection. Based on the observation that PCDHGB7 was hypermethylated in UC, we developed a bisulfite-free quantitative polymerase chain reaction (qPCR)-based PCDHGB7 evaluation to enable urine for UC noninvasive detection. A total of 887 urine samples from UC/benign diseases of the urinary system (BUD) patients between 2022 and 2023 were included. All collected samples were divided into training and validation sets in a 2:1 ratio based on the order of patient enrollment. Results showed that hypermethylated PCDHGB7 exhibited excellent sensitivity of 87.3% (95% CI: 80.7%-92.3%) and specificity of 91.0% (95% CI: 84.8%-95.3%) in efficiently distinguishing UC from BUD patients in the validation set, which is highly consistent with its performance in the training set. Moreover, PCDHGB7 hypermethylation showed promising potential in identifying sessile UC tumors or cases that might be missed in clinical detection and outperformed standard urine cytology in detecting bladder cancer (82.1% vs. 34.5%), ureter cancer (78.1% vs. 34.4%), and renal pelvis cancer (90.9% vs. 22.7%). Overall, bisulfite-free qPCR-based PCDHGB7 evaluation in urine provided a noninvasive, easy-to-perform, and effective way for UC early detection.

High metastatic propensity of osteosarcoma leads to its therapeutic failure and poor prognosis. Although nuclear activation miRNAs (NamiRNAs) are reported to activate gene transcription via targeting enhancer and further promote tumor metastasis, it remains uncertain whether NamiRNAs regulate osteosarcoma metastasis and their exact mechanism. Here, we found that extracellular vesicles of the malignant osteosarcoma cells (143B) remarkably increased the migratory abilities of MNNG cells representing the benign osteosarcoma cells by two folds, which attributed to their high miR-1246 levels. Specially, miR-1246 located in nucleus could activate the migration gene expression (such as MMP1) to accelerate MNNG cell migration through elevating the enhancer activities via increasing H3K27ac enrichment. Instead, MMP1 expression was dramatically inhibited after Argonaute 2 (AGO2) knockdown. Notably, in vitro assays demonstrated that AGO2 recognized the hybrids of miR-1246 and its enhancer DNA via PAZ domains to prevent their degradation from RNase H and these protective roles of AGO2 may favor the gene activation by miR-1246 in vivo. Collectively, our findings suggest that miR-1246 could facilitate osteosarcoma metastasis through interacting with enhancer to activate gene expression dependent on AGO2, highlighting the nuclear AGO2 as a guardian for NamiRNA-targeted gene activation and the potential of miR-1246 for osteosarcoma metastasis therapy.

Foliar diseases of agricultural crops seriously affect the yield and quality of crops, but the number of corresponding crop foliar disease image samples is limited, which leads to training difficulties. In order to solve this problem, this paper innovatively proposes a transfer learning-based method that uses the pre-trained model trained on a large-scale dataset for feature extraction and parameter adjustment, and transfers the knowledge on the large-scale dataset to a small-sample dataset for training and classification of cassava leaf disease. The experimental results confirmed that the method effectively overcame the problem of small samples, significantly improved the identification accuracy of cassava leaf diseases, and provided a powerful tool for the diagnosis and analysis of cassava leaf diseases.

Background Implementation of high-risk human papillomavirus (hrHPV) screening has greatly reduced the incidence and mortality of cervical cancer. However, a triage strategy that is effective, noninvasive, and independent from the subjective interpretation of pathologists is urgently required to decrease unnecessary colposcopy referrals in hrHPV-positive women. Methods A total of 3251 hrHPV-positive women aged 30–82 years (median = 41 years) from International Peace Maternity and Child Health Hospital were included in the training set ( n = 2116) and the validation set ( n = 1135) to establish Cervical cancer Methylation (CerMe) detection. The performance of CerMe as a triage for hrHPV-positive women was evaluated. Results CerMe detection efficiently distinguished cervical intraepithelial neoplasia grade 2 or worse (CIN2 +) from cervical intraepithelial neoplasia grade 1 or normal (CIN1 −) women with excellent sensitivity of 82.4% (95% CI = 72.6 ~ 89.8%) and specificity of 91.1% (95% CI = 89.2 ~ 92.7%). Importantly, CerMe showed improved specificity (92.1% vs. 74.9%) in other 12 hrHPV type-positive women as well as superior sensitivity (80.8% vs. 61.5%) and specificity (88.9% vs. 75.3%) in HPV16/18 type-positive women compared with cytology testing. CerMe performed well in the triage of hrHPV-positive women with ASC-US (sensitivity = 74.4%, specificity = 87.5%) or LSIL cytology (sensitivity = 84.4%, specificity = 83.9%). Conclusions PCDHGB7 hypermethylation-based CerMe detection can be used as a triage strategy for hrHPV-positive women to reduce unnecessary over-referrals. Trial registration ChiCTR2100048972. Registered on 19 July 2021.

microRNAs (miRNAs) are short non-coding RNAs that have been increasingly recognized for their significant roles in the progression of cancer. Distinct miRNAs exhibit diverse functions attributed to variations in their sequences. As a result of possessing highly homologous seed sequences, these miRNAs target overlapping or similar gene sets, thus performing analogous roles. However, different from this sight, our study discovered that miR-135a-5p and miR-135b-5p, despite differing by only one nucleotide, exhibit distinct functional roles. Using non-small cell lung cancer (NSCLC) as a paradigm, our findings unveiled the downregulation of miR-135a-5p and upregulation of miR-135b-5p within NSCLC through TCGA database. Consequently, we further investigated their functional differences in A549 cells. Overexpression of miR-135b-5p enhanced the proliferation and migration capabilities of A549 cells, whereas miR-135a-5p transfection exhibited the opposite effect. We demonstrated that the activation of specific enhancers serves as a crucial mechanism underlying the disparate functions exerted by miR-135a-5p and miR-135b-5p in the context of NSCLC, consequently instigating a shift from inhibition to activation in NSCLC progression. Finally, we validated through animal experiments that miR-135b-5p promoted tumor progression, while miR-135a-5p exerted inhibitory effects on NSCLC development. This study offers a novel perspective for researchers to elucidate functional disparities exhibited by highly homologous miRNAs (miR-135a-5p and miR-135b-5p) in the context of NSCLC, along with the transition from inhibitory to progressive states in NSCLC. This study provides a solid foundation for future investigations into the functional roles of highly homologous miRNAs in pathological situation.

Background The strong invasiveness and rapid expansion of dengue virus (DENV) pose a great challenge to global public health. However, dengue epidemic patterns and mechanisms at a genetic scale, particularly in term of cross-border transmissions, remain poorly understood. Importation is considered as the primary driver of dengue outbreaks in China, and since 1990 a frequent occurrence of large outbreaks has been triggered by the imported cases and subsequently spread to the western and northern parts of China. Therefore, this study aims to systematically reveal the invasion and diffusion patterns of DENV-1 in Guangdong, China from 1990 to 2019.Methods These analyses were performed on 179 newly assembled genomes from indigenous dengue cases in Guangdong, China and 5152 E gene complete sequences recorded in Chinese mainland. The genetic population structure and epidemic patterns of DENV-1 circulating in Chinese mainland were characterized by phylogenetics, phylogeography, phylodynamics based on DENV-1 E-gene-based globally unified genotyping framework.Results Multiple serotypes of DENV were co-circulating in Chinese mainland, particularly in Guangdong and Yunnan provinces. A total of 189 transmission clusters in 38 clades belonging to 22 subgenotypes of genotype I, IV and V of DENV-1 were identified, with 7 Clades of Concern (COCs) responsible for the large outbreaks since 1990. The epidemic periodicity was inferred from the data to be approximately 3 years. Dengue transmission events mainly occurred from Great Mekong Subregion-China (GMS-China), Southeast Asia (SEA), South Asia Subcontinent (SASC), and Oceania (OCE) to coastal and land border cities respectively in southeastern and southwestern China. Specially, Guangzhou was found to be the most dominant receipting hub, where DENV-1 diffused to other cities within the province and even other parts of the country. Genome phylogeny combined with epidemiological investigation demonstrated a clear local consecutive transmission process of a 5C1 transmission cluster (5C1-CN4) of DENV-1 in Guangzhou from 2013 to 2015, while the two provinces of Guangdong and Yunnan played key roles in ongoing transition of dengue epidemic patterns. In contextualizing within Invasion Biology theories, we have proposed a derived three-stage model encompassing the stages of invasion, colonization, and dissemination, which is supposed to enhance our understanding of dengue spreading patterns.Conclusions This study demonstrates the invasion and diffusion process of DENV-1 in Chinese mainland within a global genotyping framework, characterizing the genetic diversities of viral populations, multiple sources of importation, and periodic dynamics of the epidemic. These findings highlight the potential ongoing transition trends from epidemic to endemic status offering a valuable insight into early warning, prevention and control of rapid spreading of dengue both in China and worldwide.

Background More than half of the global population lives in areas at risk of dengue (DENV) transmission. Developing an efficient risk prediction system can help curb dengue outbreaks, but multiple variables, including mosquito-based surveillance indicators, still constrain our understanding. Mosquito or oviposition positive index (MOI) has been utilized in field surveillance to monitor the wild population density of Aedes albopictus in Guangzhou since 2005. Methods Based on the mosquito surveillance data using Mosq-ovitrap collection and human landing collection (HLC) launched at 12 sites in Guangzhou from 2015 to 2017, we established a MOI-based model of the basic dengue reproduction number ( R 0 ) using the classical Ross-Macdonald framework combined with a linear mixed-effects model. Results During the survey period, the mean MOI and adult mosquito density index (ADI) using HLC for Ae. albopictus were 12.96 ± 17.78 and 16.79 ± 55.92, respectively. The R 0 estimated from the daily ADI (ADI D ) showed a significant seasonal variation. A 10-unit increase in MOI was associated with 1.08-fold (95% CI 1.05, 1.11) ADI D and an increase of 0.14 (95% CI 0.05, 0.23) in the logarithmic transformation of R 0 . MOI-based R 0 of dengue varied by month and average monthly temperature. During the active period of Ae. albopictus from April to November in Guangzhou region, a high risk of dengue outbreak was predicted by the MOI-based R 0 model, especially from August to October, with the predicted R 0 > 1. Meanwhile, from December to March, the estimates of MOI-based R 0 were < 1. Conclusions The present study enriched our knowledge about mosquito-based surveillance indicators and indicated that the MOI of Ae. albopictus could be valuable for application in estimating the R 0 of dengue using a statistical model. The MOI-based R 0 model prediction of the risk of dengue transmission varied by month and temperature in Guangzhou. Our findings lay a foundation for further development of a complex efficient dengue risk prediction system. Graphical Abstract

Abstract Background Urothelial carcinoma (UC) is the second most common urological malignancy. Despite numerous molecular markers have been evaluated during the past decades, no urothelial markers for diagnosis and recurrence monitoring have shown consistent clinical utility. Methods The methylation level of tissue samples from public database and clinical collected were analyzed. Patients with UC and benign diseases of the urinary system (BUD) were enrolled to establish TAGMe (TAG of Methylation) assessment in a training cohort (n = 567) using restriction enzyme-based bisulfite-free qPCR. The performance of TAGMe assessment was further verified in the validation cohort (n = 198). Urine samples from 57 UC patients undergoing postoperative surveillance were collected monthly for six months after surgery to assess the TAGMe methylation. Results We identified TAGMe as a potentially novel Universal-Cancer-Only Methylation (UCOM) marker was hypermethylated in multi-type cancers and investigated its application in UC. Restriction enzyme-based bisulfite-free qPCR was used for detection, and the results of which were consistent with gold standard pyrosequencing. Importantly, hypermethylated TAGMe showed excellent sensitivity of 88.9% (95% CI: 81.4–94.1%) and specificity of 90.0% (95% CI: 81.9–95.3%) in efficiently distinguishing UC from BUD patients in urine and also performed well in different clinical scenarios of UC. Moreover, the abnormality of TAGMe as an indicator of recurrence might precede clinical recurrence by three months to one year, which provided an invaluable time window for timely and effective intervention to prevent UC upstaging. Conclusion TAGMe assessment based on a novel single target in urine is effective and easy to perform in UC diagnosis and recurrence monitoring, which may reduce the burden of cystoscopy. Trial registration ChiCTR2100052507. Registered on 30 October 2021

目的 了解2021年广州市新冠病毒接触风险人员的新冠病毒加强疫苗接种意愿现状及影响因素,为疫苗普及提供依据.方法 于2021年8月对广州市新冠病毒接触风险人群进行问卷调查,采用Logistic回归分析其接种加强疫苗意愿的影响因素.结果 共调查3703人,其中高风险与中等风险分别为181人和3522人,其加强疫苗接种意愿较高(分别占87.8％与87.9％).Logistic回归分析显示,高风险组接种意愿影响因素为月收入、抑郁状态、对新冠疫苗效果的信心;中等风险组影响因素为教育水平、工作类型、既往接种新冠剂次、对新冠疫苗效果的信心、社会责任(P<0.05).结论 广州市新冠病毒接触风险人群加强疫苗接种意愿较高,在后续疫苗推广中,需了解不同人员的特征,加强疫苗知识宣传,增强居民对疫苗效果的信心.

AbstractBackgroundThe number of human rabies cases caused by pet dogs in Guangzhou has been decreasing after years of comprehensive interventions. Consequently, attacks by stray dogs become a major issue in rabies control.ObjectivesTo share our experience of successfully dealing with rabies to provide some inspiration for prevention and control in countries and regions affected by it.MethodsA multidisciplinary One Health response was initiated to control this outbreak. Rabies virus was detected by PCR in the brain tissue of the associated stray dog. The sequences were aligned with reference sequences downloaded from GenBank using ClustalX. The maximum likelihood method implemented in MEGA 5.0 software package was used in a phylogenetic analysis of the aligned sequences.ResultsTwelve patients with exposure to the stray dog were identified in the field investigation. Rabies vaccines and immunoglobulin were administered to all patients within 48 h. After 1 year of follow‐up, no exposed patients showed symptoms. Maximum likelihood analysis of the nucleotide sequences obtained from the PCR products indicated that the rabies virus in the dog was closely related to isolates from neighbouring provinces of Guangdong as well as those from surrounding countries of China.ConclusionsMultidisciplinary One Health intervention is effective not only in the control of rabies but also in rapid emergency responses to attacks by rabid stray dogs.

Background: Leptospirosis, which is an easily overlooked zoonotic disease, was once widespread in Guangzhou, China. However, due to the implementation of control measures, the number of cases is decreasing. Based on the characteristics of leptospirosis cases in Guangzhou, China, between 1955 and 2020, we describe the changes and achievements in prevention and control management strategies over that period.Methods: The development of the leptospirosis control system in Guangzhou occurred over three periods: Period I: 1955-1978; Period II: 1979-2000; and Period III: 2001-2020. Data about leptospirosis cases were obtained from the Guangzhou Center for Disease Control and Prevention (CDC) and national health departments. The demographic characteristics of leptospirosis patients were analyzed using descriptive statistics.Results: During Period I, only the Guangzhou CDC and medical institutions at every level participated in the leptospirosis control system. During Period II, additional types of organizations, including local CDCs, countryside committees, community committees, and the Patriotic Health Movement Commission, were involved in the control system. Additionally, strong links were established between different organizations. After entering Period III, an increasing number of departments joined the cooperation, and the management of human patients was expanded to include the management of host animals, and thus, the prevalence of leptospirosis was monitored and controlled in various ways. The leptospirosis control system in Guangzhou has been further improved. From 1955 to 2020, a total of 2501 leptospirosis cases were recorded in Guangzhou, and the number of cases decreased significantly over time, from 1608 (Period I) to 744 (Period II) and then to 149 (Period III).Conclusion: The improvements of the leptospirosis control system in Guangzhou that occurred over decades were associated with a marked decrease in the number of leptospirosis cases. Guangzhou's experience can provide guidance for other countries or cities around the world facing similar challenges.

Objective To understand the change of incidence of notifiable communicable diseases in Guangzhou during the epidemic of COVID-19 in 2020. Methods The data in this study were collected from the National Communicable Disease Reporting Information System. We applied descriptive analysis to compare the incidence of reported notifiable communicable diseases in Guangzhou for COVID-19 in four different time stages in 2020 and 2015-2019. R 3.5.0 software was used for statistical analysis. Results The incidence rate of reported notifiable communicable diseases in four different time stages in Guangzhou was 272.38/10~5, 51.16/10~5, 130.34/10~5 and 664.25/10~5 in 2020, respectively. The incidence rates increased by 187.76%,-30.37%,-57.64% and-41.85% respectively, compared with the average level in 2015-2019, especially the incidence rate of class C communicable diseases. All kinds of different transmission communicable diseases of class A and B decreased significantly after starting the first-level response. However, it decreased slowly in the second and third level response except for natural focal communicable diseases and vector-borne diseases. The incidence rate of acute communicable diseases such as influenza decreased significantly after the first-level response and decreased faster after the second-level response. However, the incidence rate of chronic communicable diseases such as HIV/AIDS, syphilis and hepatitis B decreased after the first-level response, but declined narrowed after the second and third level response. Conclusions The incidence rate of reported notifiable communicable diseases has changed significantly before and after the epidemic of COVID-19, especially that of acute communicable diseases such as influenza, and even in the late stage of the epidemic.

Background Aedes albopictus is an invasive vector of serious Aedes-borne diseases of global concern. Habitat management remains a critical factor for establishing a cost-effective systematic strategy for sustainable vector control. However, the community-based characteristics of Ae. albopictus habitats in complex urbanization ecosystems are still not well understood.Methods A large-scale investigation of aquatic habitats, involving 12 sites selected as representative of four land use categories at three urbanization levels, was performed in Guangzhou, China during 2015-2017. The characteristics and dynamics of these Ae. albopictus habitats were assessed using habitat-type composition, habitat preference, diversity indexes and the Route index (RI), and the temporal patterns of these indexes were evaluated by locally weighted scatterplot smoothing models. The associations of RI with urbanization levels, land use categories and climatic variables were inferred using generalized additive mixed models.Results A total of 1994 potential habitats and 474 Ae. albopictus-positive habitats were inspected. The majority of these habitats were container-type habitats, with Ae. albopictus showing a particularly higher habitat preference for plastic containers, metal containers and ceramic vessels. Unexpectedly, some non-container-type habitats, especially ornamental ponds and surface water, were found to have fairly high Ae. albopictus positivity rates. Regarding habitats, the land use category residential and rural in Jiangpu (Conghua District, Guangzhou) had the highest number of Ae. albopictus habitats with the highest positive rates. The type diversity of total habitats (H-total) showed a quick increase from February to April and peaked in April, while the H-total of positive habitats (H-positive) and RIs peaked in May. RIs mainly increased with the monthly average daily mean temperature and monthly cumulative rainfall. We also observed the accumulation of diapause eggs in the winter and diapause termination in the following March.Conclusions Ecological heterogeneity of habitat preferences of Ae. albopictus was demonstrated in four land use categories at three urbanization levels. The results reveal diversified habitat-type compositions and significant seasonal variations, indicating an ongoing adaptation of Ae. albopictus to the urbanization ecosystem. H-positivity and RIs were inferred as affected by climatic variables and diapause behavior of Ae. albopictus, suggesting that an effective control of overwintering diapause eggs is crucial. Our findings lay a foundation for establishing a stratified systematic management strategy of Ae. albopictus habitats in cities that is expected to complement and improve community-based interventions and sustainable vector management.

Objective To study prevalence characteristics and change pattern of dominant virus strain of influenza epidemics in Guangzhou city and to provide evidence for formulating region-specific prevention and control measures. Methods Weekly influenza surveillance data of Guangzhou city, Guangdong province from 2015 to 2022 were collected from China Influenza Surveillance Information System. The positive rate series of influenza virus and its pathogen subtype were decomposed into trend/season/remainder component by using the seasonal-trend decomposition procedure based on locally weighted regression. By calculating covariance, the contribution rate of the obtained components to the fluctuation of positive rate was analyzed. Results Of 39 198 surveillance specimens sampled in the city during the 8-year period, 3 632 (9.27%) were positive for influenza virus nucleic acid. Trend series analysis showed that the positive rate fluctuated from 4.57% to 16.07%, with an increasing trend, during 2015 – 2019 and varied with a U-shape trajectory during 2020 – 2022. Winter-spring and spring-summer peaks of the positive rate were observed in season series analysis and the remainder component analysis revealed the highest fluctuation range of 48.96% for the positive rate in 2022. The positive rate of influenza A (H3N2) presented a similar season series to that of influenza B (Victoria), with winter and summer peaks, but the summer peaks of influenza A (H3N2) was later than that of influenza B (Victoria); the peak shape and prevalence duration (single peaks mainly in winter-spring season) of influenza A (H1N1) pdm09 positivity were similar to those of influenza B (Yamagata). In general, the remainder component was the main contributor to the fluctuation of the total positive rate, accounting for 59.16% of overall fluctuation (covariance of remainder component versus that of original series: 80.81/136.60), followed by season and trend component, accounting for 25.19% (34.41/136.60) and 15.68% (21.38/136.60) of overall fluctuation, respectively. Conclusion There were virus subtype-specific differences in seasonal peak and prevalence duration of influenza infection and random fluctuation exerted a greater effect than long-term trend and seasonal variation on influenza epidemic pattern in Guangzhou city.

The SARS-CoV-2 B.1.617.2 (Delta) variant flared up in late May in Guangzhou, China. Transmission characteristics of Delta variant were analysed for 153 confirmed cases and two complete transmission chains with seven generations were fully presented. A rapid transmission occurred in five generations within 10 days. The basic reproduction number (R0) was 3.60 (95% confidence interval: 2.50-5.30). After redefining the concept of close contact, the proportion of confirmed cases discovered from close contacts increased from 43% to 100%. With the usage of a yellow health code, the potential exposed individuals were self-motivated to take a nucleic acid test and regained public access with a negative testing result. Facing the massive requirement of screening, novel facilities like makeshift inflatable laboratories were promptly set up as a vital supplement and 17 cases were found, with 1 pre-symptomatic. The dynamic adjustment of these three interventions resulted in the decline of Rt from 5.00 to 1.00 within 9 days. By breaking the transmission chain and eliminating the transmission source through extending the scope of the close-contact tracing, health-code usage and mass testing, the Guangzhou Delta epidemic was effectively contained.

Little evidence exists concerning the associations of greenspace with childhood lipid profiles and dyslipidemias, especially in developing countries and regions. We aimed to investigate the associations of greenspace surrounding schools with lipid levels and dyslipidemia prevalence among Chinese children and teenagers. We obtained baseline information and health data of 10,408 children and teenagers (aged 6-18 years) who studied from 94 schools in China. We measured levels of four blood lipids: triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C). Dyslipidemias were defined using standard recommendations. Greenness surrounding schools were assessed using two satellite-based greenness indices, Normalized Difference Vegetation Index (NDVI) and Soil Adjusted Vegetation Index (SAVI) at 300-, 500-, and 1000-m circular buffers based on each school's latitude and longitude. We used random forest model combined with meteorological and remote sensing data to estimate air pollution levels surrounding each school. We used generalized linear mixed models to estimate the associations of greenness with lipid levels and dyslipidemias prevalence. We also performed sub-group and mediation analyses. An interquartile range (IQR) increase in NDVI500m was significantly associated with a 0.064 mmol/L (95% confidence interval [CI]: 0.083, -0.045) and 0.049 mmol/L (95% CI: 0.065, -0.033) decreased TC and LDL-C levels, respectively, as well as a 0.13-fold (95% CI: 0.01, 0.23) and 0.17-fold (95% CI: 0.01, 0.30) decreased odds of hypercholesterolemia and hyperbetalipoproteinemia, respectively. Associations were stronger in students aged <= 12 years and born to parents having lower education levels compared to their counterparts. Particle with aerodynamic diameter <= 2.5 mu m (PM2.5) mediated 61.5% and 16.7% of the association of greenness with TG and LDL-C levels, respectively. In summary, higher school-based greenness exposure was beneficially associated with lipid levels among Chinese children and adolescents, and part of the association can be explained by lowed PM2.5 levels.

Objective: To assess the incidence of dengue fever and E gene evolution of dengue virus in Guangzhou in 2020 and understand the local epidemiological characteristics of dengue fever and spreading of dengue virus. Methods: The information of dengue fever cases in Guangzhou in 2020 was collected from Notifiable Infectious Disease System of Chinese Center for Disease Control and Prevention Information System. Serum samples from the cases were detected by real-time PCR. The E gene was sequenced and analyzed. Maximum likelihood phylogenetic trees were constructed using software MEGA 5.05. The statistical analysis was conducted using software SPSS 20.0. Results: A total of 33 dengue fever cases were reported in Guangzhou in 2020, including 31 (93.94%) imported cases and 2 (6.06%) local cases. Compared with the data during 2016 to 2019, the number of cases, overall incidence and local incidence all decreased with statistically significant differences (all P<0.05). The imported cases from Southeast Asia constituted 90.32% (28/31) of imported cases. The E gene sequences and the phylogenetic trees of imported and local cases demonstrated close relationship with the virus sequences from Southeast Asian, and they were less homologous with the sequences of dengue virus isolated in Guangzhou in previous years. Conclusions: The incidence of dengue in Guangzhou in 2020 was significantly affected by the imported cases, especially those from Southeast Asian countries. The study result demonstrated that dengue fever was not endemic in Guangzhou and it was caused by imported ones.