Facilitating fine-grained intra-urban dengue forecasting by integrating urban environments measured from street-view images

Background

Dengue fever (DF) is a mosquito-borne infectious disease that has threatened tropical and subtropical regions in recent decades. An early and targeted warning of a dengue epidemic is important for vector control. Current studies have primarily determined weather conditions to be the main factor for dengue forecasting, thereby neglecting that environmental suitability for mosquito breeding is also an important factor, especially in fine-grained intra-urban settings. Considering that street-view images are promising for depicting physical environments, this study proposes a framework for facilitating fine-grained intra-urban dengue forecasting by integrating the urban environments measured from street-view images.

Methods

The dengue epidemic that occurred in 167 townships of Guangzhou City, China, between 2015 and 2019 was taken as a study case. First, feature vectors of street-view images acquired inside each township were extracted by a pre-trained convolutional neural network, and then aggregated as an environmental feature vector of the township. Thus, townships with similar physical settings would exhibit similar environmental features. Second, the environmental feature vector is combined with commonly used features (e.g., temperature, rainfall, and past case count) as inputs to machine-learning models for weekly dengue forecasting.

Results

The performance of machine-learning forecasting models (i.e., MLP and SVM) integrated with and without environmental features were compared. This indicates that models integrating environmental features can identify high-risk urban units across the city more precisely than those using common features alone. In addition, the top 30% of high-risk townships predicted by our proposed methods can capture approximately 50–60% of dengue cases across the city.

Conclusions

Incorporating local environments measured from street view images is effective in facilitating fine-grained intra-urban dengue forecasting, which is beneficial for conducting spatially precise dengue prevention and control.

Antibody seroprevalence in the epicenter Wuhan, Hubei, and six selected provinces after containment of the first epidemic wave of COVID-19 in China

BACKGROUND

China implemented containment measures to stop SARS-CoV-2 transmission in response to the COVID-19 epidemic. After the first epidemic wave, we conducted population-based serological surveys to determine extent of infection, risk factors for infection, and neutralization antibody levels to assess the real infections in the random sampled population.

METHODS

We used a multistage, stratified cluster random sampling strategy to conduct serological surveys in three areas - Wuhan, Hubei Province outside Wuhan, and six provinces selected on COVID-19 incidence and containment strategy. Participants were consenting individuals >1 year old who resided in the survey area >14 days during the epidemic. Provinces screened sera for SARS-CoV-2-specific IgM, IgG, and total antibody by two lateral flow immunoassays and one magnetic chemiluminescence enzyme immunoassay; positive samples were verified by micro-neutralization assay.

FINDINGS

We enrolled 34,857 participants (overall response rate, 92%); 427 were positive by micro-neutralization assay. Wuhan had the highest weighted seroprevalence (4•43%, 95% confidence interval [95%CI]=3•48%-5•62%), followed by Hubei-ex-Wuhan (0•44%, 95%CI=0•26%-0•76%), and the other provinces (<0•1%). Living in Wuhan (adjusted odds ratio aOR=13•70, 95%CI= 7•91-23•75), contact with COVID-19 patients (aOR=7•35, 95%CI=5•05-10•69), and age over 40 (aOR=1•36, 95%CI=1•07-1•72) were significantly associated with SARS-CoV-2 infection. Among seropositives, 101 (24%) reported symptoms and had higher geometric mean neutralizing antibody titers than among the 326 (76%) without symptoms (30±2•4 vs 15±2•1, p<0•001).

INTERPRETATION

The low overall extent of infection and steep gradient of seropositivity from Wuhan to the outer provinces provide evidence supporting the success of containment of the first wave of COVID-19 in China. SARS-CoV-2 infection was largely asymptomatic, emphasizing the importance of active case finding and physical distancing. Virtually the entire population of China remains susceptible to SARS-CoV-2; vaccination will be needed for long-term protection.

FUNDING

This study was supported by the Ministry of Science and Technology (2020YFC0846900) and the National Natural Science Foundation of China (82041026, 82041027, 82041028, 82041029, 82041030, 82041032, 82041033).

Intra-host variation and evolutionary dynamics of SARS-CoV-2 populations in COVID-19 patients

BACKGROUND

Since early February 2021, the causative agent of COVID-19, SARS-CoV-2, has infected over 104 million people with more than 2 million deaths according to official reports. The key to understanding the biology and virus-host interactions of SARS-CoV-2 requires the knowledge of mutation and evolution of this virus at both inter- and intra-host levels. However, despite quite a few polymorphic sites identified among SARS-CoV-2 populations, intra-host variant spectra and their evolutionary dynamics remain mostly unknown.

METHODS

Using high-throughput sequencing of metatranscriptomic and hybrid captured libraries, we characterized consensus genomes and intra-host single nucleotide variations (iSNVs) of serial samples collected from eight patients with COVID-19. The distribution of iSNVs along the SARS-CoV-2 genome was analyzed and co-occurring iSNVs among COVID-19 patients were identified. We also compared the evolutionary dynamics of SARS-CoV-2 population in the respiratory tract (RT) and gastrointestinal tract (GIT).

RESULTS

The 32 consensus genomes revealed the co-existence of different genotypes within the same patient. We further identified 40 intra-host single nucleotide variants (iSNVs). Most (30/40) iSNVs presented in a single patient, while ten iSNVs were found in at least two patients or identical to consensus variants. Comparing allele frequencies of the iSNVs revealed a clear genetic differentiation between intra-host populations from the respiratory tract (RT) and gastrointestinal tract (GIT), mostly driven by bottleneck events during intra-host migrations. Compared to RT populations, the GIT populations showed a better maintenance and rapid development of viral genetic diversity following the suspected intra-host bottlenecks.

CONCLUSIONS

Our findings here illustrate the intra-host bottlenecks and evolutionary dynamics of SARS-CoV-2 in different anatomic sites and may provide new insights to understand the virus-host interactions of coronaviruses and other RNA viruses.

The moving epidemic method applied to influenza surveillance in Guangdong, China

OBJECTIVES

The moving epidemic method (MEM) has been well used for assessing seasonal influenza epidemics in temperate regions. This study used the MEM to establish epidemic threshold for influenza in Guangdong, a subtropical province in China.

METHODS

Influenza virology surveillance data from 2011/2012 to 2017/2018 seasons in Guangdong were used with the MEM to calculate the epidemic thresholds and timeously detect the 2018/2019 influenza season epidemic. The weekly positive proportion of influenza A(H1N1)pdm09, A(H3N2), B/Victoria-lineage and B/Yamagata-lineage were separately adapted to calculate the subtype-specific epidemic thresholds. The performance of MEM was evaluated using a cross-validation procedure.

RESULTS

For the 2018/2019 influenza season, the epidemic threshold of a weekly positive proportion was 15.08%. Epidemic detection for the 2018/2019 season was 1 week in advance. Influenza A(H1N1)pdm09, B/Yamagata-lineage and B/Victoria-lineage prevailed during winter and spring and their epidemic thresholds were 5.12%, 4.53% and 4.38%, respectively. Influenza A(H3N2) was active in the summer, with an epidemic threshold of 11.99%.

CONCLUSIONS

Using influenza virology surveillance data stratified by types of influenza virus, the MEM was effectively used in Guangdong, China. This study provided a practical way for subtropical regions to establish local influenza epidemic thresholds.

[Clinical outcomes of COVID-19 cases and influencing factors in Guangdong province]

Objective: To analyze the clinical courses and outcomes of COVID-19 cases and the influencing factors in Guangdong province and provide basis for the formulation or adjustment of medical care and epidemic control strategy for COVID-19. Methods: We collected demographic data, medical histories, clinical courses and outcomes of 1 350 COVID-19 patients reported in Guangdong as of 4 March 2020 via epidemiological investigation and process tracking. Disease severity and clinical course characteristics of the patients and influencing factors of severe illness were analyzed in our study. Results: Among 1 350 cases of COVID-19 cases in Guangdong, 72 (5.3%) and 1 049 (77.7%) were mild and ordinary cases, 164 (12.1%) were severe cases, 58 (4.3%) were critical cases and 7 (0.5%) were fatal. The median duration of illness were 23 days (P(25), P(75): 18, 31 days) and the median length of hospitalization were 20 days (P(25), P(75): 15,27 days). For severe cases, the median time of showing severe manifestations was on the 12(th) day after onset (P(25), P(75): 9(th) to 15(th) days), and the median time of severe manifestation lasted for 8 days (P(25), P(75): 4, 14 days). Among 1 066 discharged/fetal cases, 36.4% (36/99) and 1.0% (1/99) of the mild cases developed to ordinary cases and severe cases respectively after admission; and 5.2% (50/968) and 0.6% (6/968) of the ordinary cases developed to severe cases, and critical cases respectively after admission. In severe cases, 11.4% developed to critical cases (10/88). The influencing factors for severe illness or worse included male (aHR=1.87, 95%CI: 1.43-2.46), older age (aHR=1.67, 95%CI: 1.51-1.85), seeking medical care on day 2-3 after onset (aHR=1.73, 95%CI: 1.20-2.50) pre-existing diabetes (aHR=1.75, 95%CI: 1.12-2.73) and hypertension (aHR=1.49, 95%CI: 1.06-2.09). Conclusions: The course of illness and length of hospitalization of COVID-19 cases were generally long and associated with severity of disease clinical outcomes. The severe cases were mainly occurred in populations at high risk. In the epidemic period, classified management of COVID-19 cases should be promoted according to needs for control and prevention of isolation and treatment for the purpose of rational allocation of medical resources.

Dengue fever transmission between a construction site and its surrounding communities in China

BACKGROUND

Due to an increase in mosquito habitats and the lack facilities to carry out basic mosquito control, construction sites in China are more likely to experience secondary dengue fever infection after importation of an initial infection, which may then increase the number of infections in the neighboring communities and the chance of community transmission. The aim of this study was to investigate how to effectively reduce the transmission of dengue fever at construction sites and the neighboring communities.

METHODS

The Susceptible-Exposed-Infectious/Asymptomatic-Recovered (SEIAR) model of human and SEI model of mosquitoes were developed to estimate the transmission of dengue virus between humans and mosquitoes within the construction site and within a neighboring community, as well between each of these. With the calibrated model, we further estimated the effectiveness of different intervention scenarios targeting at reducing the transmissibility at different locations (i.e. construction sites and community) with the total attack rate (TAR) and the duration of the outbreak (DO).

RESULTS

A total of 102 construction site-related and 131 community-related cases of dengue fever were reported in our area of study. Without intervention, the number of cases related to the construction site and the community rose to 156 (TAR: 31.25%) and 10,796 (TAR: 21.59%), respectively. When the transmission route from mosquitoes to humans in the community was cut off, the number of community cases decreased to a minimum of 33 compared with other simulated scenarios (TAR: 0.068%, DO: 60 days). If the transmission route from infectious mosquitoes in the community and that from the construction site to susceptible people on the site were cut off at the same time, the number of cases on the construction site dropped to a minimum of 74 (TAR: 14.88%, DO: 66 days).

CONCLUSIONS

To control the outbreak of dengue fever effectively on both the construction site and in the community, interventions needed to be made both within the community and from the community to the construction site. If interventions only took place within the construction site, the number of cases on the construction site would not be reduced. Also, interventions implemented only within the construction site or between the construction site and the community would not lead to a reduction in the number of cases in the community.

Overexpression of DJ-1 expression protects cardiomyocyte apoptosis induced by ischemia reperfusion

Since this article has been suspected of research misconduct and the corresponding authors did not respond to our request to prove originality of data and figures, "Overexpression of DJ-1 expression protects cardiomyocyte apoptosis induced by ischemia reperfusion, by L.-H. Xin, W.-J. Liu, T. Song, L. Zhang, published in Eur Rev Med Pharmacol Sci 2019; 23 (4): 1722-1729-DOI: 10.26355/eurrev_201902_17134-PMID: 30840297" has been withdrawn. The Publisher apologizes for any inconvenience this may cause. https://www.europeanreview.org/article/17134.

Probable Evidence of Fecal Aerosol Transmission of SARS-CoV-2 in a High-Rise Building

BACKGROUND

The role of fecal aerosols in the transmission of severe acute respiratory syndrome coronavirus 2 has been suspected.

OBJECTIVE

To investigate the temporal and spatial distributions of 3 infected families in a high-rise apartment building and examine the associated environmental variables to verify the role of fecal aerosols.

DESIGN

Epidemiologic survey and quantitative reverse transcriptase polymerase chain reaction analyses on throat swabs from the participants; 237 surface and air samples from 11 of the 83 flats in the building, public areas, and building drainage systems; and tracer gas released into bathrooms as a surrogate for virus-laden aerosols in the drainage system.

SETTING

A high-rise apartment building in Guangzhou, China.

PARTICIPANTS

9 infected patients, 193 other residents of the building, and 24 members of the building's management staff.

MEASUREMENTS

Locations of infected flats and positive environmental samples, and spread of virus-laden aerosols.

RESULTS

9 infected patients in 3 families were identified. The first family had a history of travel to the coronavirus disease 2019 (COVID-19) epicenter Wuhan, whereas the other 2 families had no travel history and a later onset of symptoms. No evidence was found for transmission via the elevator or elsewhere. The families lived in 3 vertically aligned flats connected by drainage pipes in the master bathrooms. Both the observed infections and the locations of positive environmental samples are consistent with the vertical spread of virus-laden aerosols via these stacks and vents.

LIMITATION

Inability to determine whether the water seals were dried out in the flats of the infected families.

CONCLUSION

On the basis of circumstantial evidence, fecal aerosol transmission may have caused the community outbreak of COVID-19 in this high-rise building.

PRIMARY FUNDING SOURCE

Key-Area Research and Development Program of Guangdong Province and the Research Grants Council of Hong Kong.

Risk factors associated with COVID-19 infection: a retrospective cohort study based on contacts tracing

This study aimed to estimate the attack rates, and identify the risk factors of COVID-19 infection. Based on a retrospective cohort study, we investigated 11,580 contacts of COVID-19 cases in Guangdong Province from 10 January to 15 March 2020. All contacts were tested by RT-PCR to detect their infection of SARS-COV-2. Attack rates by characteristics were calculated. Logistic regression was used to estimate the risk factors of infection for COVID-19. A total of 515 of 11,580 contacts were identified to be infected with SARS-COV-2. Compared to young adults aged 20-29 years, the infected risk was higher in children (RR: 2.59, 95%CI: 1.79-3.76), and old people aged 60-69 years (RR: 5.29, 95%CI: 3.76-7.46). Females also had higher infected risk (RR: 1.66, 95%CI: 1.39-2.00). People having close relationship with index cases encountered higher infected risk (RR for spouse: 20.68, 95%CI: 14.28-29.95; RR for non-spouse family members: 9.55, 95%CI: 6.73-13.55; RR for close relatives: 5.90, 95%CI: 4.06-8.59). Moreover, contacts exposed to index case in symptomatic period (RR: 2.15, 95%CI: 1.67-2.79), with critically severe symptoms (RR: 1.61, 95%CI: 1.00-2.57), with symptoms of dizzy (RR: 1.58, 95%CI: 1.08-2.30), myalgia (RR: 1.49, 95%CI: 1.15-1.94), and chill (RR: 1.42, 95%CI: 1.05-1.92) had higher infected risks. Children, old people, females, and family members are susceptible of COVID-19 infection, while index cases in the incubation period had lower contagiousness. Our findings will be helpful for developing targeted prevention and control strategies to combat the worldwide pandemic.

The time-varying transmission dynamics of COVID-19 and synchronous public health interventions in China

Objectives

We aimed to estimate the time-varying transmission dynamics of COVID-19 in China, Wuhan City, and Guangdong province, and compare to that of severe acute respiratory syndrome (SARS).

Methods

Data on COVID-19 cases in China up to 20 March 2020 was collected from epidemiological investigations or official websites. Data on SARS cases in Guangdong Province, Beijing, and Hong Kong during 2002–3 was also obtained. We estimated the doubling time, basic reproduction number (R₀), and time-varying reproduction number (R_t) of COVID-19 and SARS.

Results

As of 20 March 2020, 80,739 locally acquired COVID-19 cases were identified in mainland China, with most cases reported between 20 January and 29 February 2020. The R₀ value of COVID-19 in China and Wuhan was 5.0 and 4.8, respectively, which was greater than the R₀ value of SARS in Guangdong (R₀ = 2.3), Hong Kong (R₀ = 2.3), and Beijing (R₀ = 2.6). At the start of the COVID-19 epidemic, the R_t value in China peaked at 8.4 and then declined quickly to below 1.0 in one month. With SARS, the R_t curve saw fluctuations with more than one peak, the highest peak was lower than that for COVID-19.

Conclusions

COVID-19 has much higher transmissibility than SARS, however, a series of prevention and control interventions to suppress the outbreak were effective. Sustained efforts are needed to prevent the rebound of the epidemic in the context of the global pandemic.

Kinetics of viral load and antibody response in relation to COVID-19 severity

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent for coronavirus 2019 (COVID-19) pneumonia. Little is known about the kinetics, tissue distribution, cross-reactivity, and neutralization antibody response in patients with COVID-19. Two groups of patients with RT-PCR-confirmed COVID-19 were enrolled in this study: 12 severely ill patients in intensive care units who needed mechanical ventilation and 11 mildly ill patients in isolation wards. Serial clinical samples were collected for laboratory detection. Results showed that most of the severely ill patients had viral shedding in a variety of tissues for 20-40 days after onset of disease (8/12, 66.7%), while the majority of mildly ill patients had viral shedding restricted to the respiratory tract and had no detectable virus RNA 10 days after onset (9/11, 81.8%). Mildly ill patients showed significantly lower IgM response compared with that of the severe group. IgG responses were detected in most patients in both the severe and mild groups at 9 days after onset, and remained at a high level throughout the study. Antibodies cross-reactive to SARS-CoV and SARS-CoV-2 were detected in patients with COVID-19 but not in patients with MERS. High levels of neutralizing antibodies were induced after about 10 days after onset in both severely and mildly ill patients which were higher in the severe group. SARS-CoV-2 pseudotype neutralization test and focus reduction neutralization test with authentic virus showed consistent results. Sera from patients with COVID-19 inhibited SARS-CoV-2 entry. Sera from convalescent patients with SARS or Middle East respiratory syndrome (MERS) did not. Anti-SARS-CoV-2 S and N IgG levels exhibited a moderate correlation with neutralization titers in patients' plasma. This study improves our understanding of immune response in humans after SARS-CoV-2 infection.

Transmission of pathogen-laden expiratory droplets in a coach bus

Droplet dispersion carrying viruses/bacteria in enclosed/crowded buses may induce transmissions of respiratory infectious diseases, but the influencing mechanisms have been rarely investigated. By conducting high-resolution CFD simulations, this paper investigates the evaporation and transport of solid-liquid mixed droplets (initial diameter 10 μm and 50 μm, solid to liquid ratio is 1:9) exhaled in a coach bus with 14 thermal manikins. Five air-conditioning supply directions and ambient relative humidity (RH = 35 % and 95 %) are considered. Results show that ventilation effectiveness, RH and initial droplet size significantly influence droplet transmissions in coach bus. 50 μm droplets tend to evaporate completely within 1.8 s and 7 s as RH = 35 % and 95 % respectively, while 0.2 s or less for 10 μm droplets. Thus 10 μm droplets diffuse farther with wider range than 50 μm droplets which tend to deposit more on surfaces. Droplet dispersion pattern differs due to various interactions of gravity, ventilation flows and the upward thermal body plume. The fractions of droplets suspended in air, deposited on wall surfaces are quantified. This study implies high RH, backward supply direction and passengers sitting at nonadjacent seats can effectively reduce infection risk of droplet transmission in buses. Besides taking masks, regular cleaning is also recommended since 85 %-100 % of droplets deposit on object surfaces.

Dengue Fever Outbreaks Caused by Varied Serotype Dengue Virus - Guangdong Province, China, 2019

What is already known about this topic?

Dengue fever (DF) outbreaks affect hundreds of millions of people worldwide and have increased significantly in Guangdong Province in 2019.

What is added by this report?

This paper described briefly DF outbreaks were attributed to several types of dengue virus (DENV) including DENV-1, DENV-2, and DENV-3 in 2019 in Guangdong, tracked the sources of viruses through phylogenetic analysis and epidemiological investigation, and primarily revealed the epidemiological links among the outbreaks.

What are the implications for public health practice?

The introduction of DENV from DF endemic areas increased pressure on the prevention and control of DF in Guangdong. Early detection of suspected cases and typing and genotyping of circulating viruses should be prioritized and enhanced to promptly assess the likelihood of local transmission, of introduction, and of subsequent sustained local transmission of the virus to implement optimal prevention and control strategies and measures.

Clinical, immunological and virological characterization of COVID-19 patients that test re-positive for SARS-CoV-2 by RT-PCR

BACKGROUND

Some COVID-19 cases test positive again for SARS-CoV-2 RNA following negative test results and discharge, raising questions about the meaning of virus detection. Better characterization of re-positive cases is urgently needed.

METHODS

Clinical data were obtained through Guangdong's COVID-19 surveillance network. Neutralization antibody titre was determined using microneutralization assays. Potential infectivity of clinical samples was evaluated by cell inoculation. SARS-CoV-2 RNA was detected using three different RT-PCR kits and multiplex PCR with nanopore sequencing.

FINDINGS

Among 619 discharged COVID-19 cases, 87 re-tested as SARS-CoV-2 positive in circumstances of social isolation. All re-positive cases had mild or moderate symptoms at initial diagnosis and were younger on average (median, 28). Re-positive cases (n = 59) exhibited similar neutralization antibodies (NAbs) titre distributions to other COVID-19 cases (n = 218) tested here. No infectious strain could be obtained by culture and no full-length viral genomes could be sequenced from re-positive cases.

INTERPRETATION

Re-positive SARS-CoV-2 cases do not appear to be caused by active reinfection and were identified in ~14% of discharged cases. A robust NAb response and potential virus genome degradation were detected in almost all re-positive cases, suggesting a substantially lower transmission risk, especially through respiratory routes.

[Analysis on the cluster epidemic of coronavirus disease 2019 in Guangdong Province]

Objective: Analysis of clustering characteristics of coronavirus disease 2019 (COVID-19) in Guangdong Province. Methods: The COVID-19 cases in Guangdong Province onset from January 1 to February 29, 2020 were collected from Chinese information system for disease control and prevention and Emergency Public Reporting System. Obtain the epidemiological survey data of the cluster epidemic situation, and clarify the scale of cluster epidemic situation, the characteristics of the index cases, family and non-family subsequent cases. Calculate serial interval according to the onset time of the index cases and subsequent cases, secondary attack rate based on the close contacts tracking results, the characteristics of different cases in the clustered epidemic were compared. Results: A total of 283 cluster were collected, including 633 index cases, 239 subsequent cases. Families are mainly clustered, the total number involved in each cluster is in the range of 2-27, M (P₂₅, P₇₅) are 2.0 (2.0, 4.0). During January 15 to February 29, the secondary attack rate is 2.86% (239/8 363) in Guangdong Province, the family secondary attack rate was 4.84% (276/3 697), and the non-family secondary attack rate was 1.32% (61/4 632). According to the reporting trend of the number of cases in Guangdong Province, it can be divided into four stages, the rising stage, the high platform stage, the descending stage and the low level fluctuation period. The secondary attack rate of the four stages were 3.5% (140/3 987), 2.3% (55/2 399), 2.6% (37/1 435), 1.3% (7/542), respectively. The difference was statistically significant (P=0.003). Conclusion: COVID-19 cluster mainly occurs in families in Guangdong Province. The scale of the clustered epidemic was small; the serial interval was short; and the overall secondary attack rate was low.

Overexpression of DJ-1 expression protects cardiomyocyte apoptosis induced by ischemia reperfusion

OBJECTIVE

Phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway plays an important role in regulating cell survival, apoptosis and oxidative stress (OS). Phosphatase and tensin homolog deleted on chromosome ten (PTEN) can negatively regulate PI3K/AKT signaling pathway. DJ-1 is also a key negative regulator of PTEN. DJ-1-PTEN/PI3K/AKT signaling pathway regulates ischemia reperfusion (I-R). This study investigated the role of DJ-1 in affecting myocardial I-R injury.

MATERIALS AND METHODS

The rat myocardial I-R injury model was established. Expression of DJ-1 and PTEN in myocardial tissue was detected. The reactive oxidative species (ROS) content was detected using flow cytometry. Caspase-3 activity, malondialdehyde (MDA) content, and superoxide dismutase (SOD) activities were determined by ultraviolet spectrophotometry. Rat cardiomyocytes H9C2 were cultured in vitro and divided into control group, I-R group, I-R+pIRES2-NC group, and I-R+pIRES2-DJ-1 group. Levels of DJ-1, PTEN and phosphorylated AKT (p-AKT) were detected. Cell apoptosis and ROS content were evaluated using flow cytometry.

RESULTS

Compared with sham group, caspase-3 activity, MDA content, and PTEN expression were significantly increased, while SOD activity and DJ-1 levels were significantly reduced in myocardial tissue of I-R group (p<0.05). Compared with the control, I-R treatment markedly induced H9C2 cell apoptosis, decreased DJ-1 and p-AKT expression, and enhanced ROS production and PTEN expression. DJ-1 overexpression apparently down-regulated PTEN expression, elevated p-AKT level, and attenuated apoptosis and ROS production in H9C2 cells (p<0.05).

CONCLUSIONS

Abnormal expression of DJ-1 plays a regulatory role in the process of myocardial I-R injury. Over-expression of DJ-1 can reduce myocardial cell I-R damage sensitivity by inhibiting PTEN expression, enhancing the activity of PI3K/AKT signaling pathway, reducing ROS production, and alleviating apoptosis.

[Clinical effects of free thinned deep inferior epigastric artery perforator flap in repairing extensive soft tissue defects in extremities]

Objective: To explore the feasibility and clinical effects of using free thinned deep inferior epigastric artery perforator flap to repair extensive soft tissue defects in extremities. Methods: From April 2010 to January 2014, 12 patients with extensive soft tissue defect in extremities after trauma, including 10 males and 2 females, aged 21 to 48 years, 6 patients with defect in the back of wrist and 6 patients with defect in ankle were admitted to the Department of Bone Microsurgery of Xi'an Honghui hospital. After debridement, the size of soft tissue defect ranged from 15.0 cm×4.5 cm to 28.0 cm×11.0 cm. The free thinned deep inferior epigastric artery perforator flap was designed, cut and transferred for reconstruction, with size of 15.0 cm×5.0 cm to 29.0 cm×12.0 cm. The flap thickness ranged from 4.0 to 6.5 cm before defatting, and was 0.6 to 0.9 cm after defatting. All the donor sites of flaps were closed directly by suturing. The flap survival and the appearance and function of flap and donor site were observed during follow-up. Results: All the flaps survived smoothly after surgery. During follow-up of 10 to 42 months, the flaps showed no bloat in appearance, no further flap revision or defatting procedures were required, the distance of static 2-point discrimination was 11 to 17 mm (14.5 mm on average). The abdominal function of patients was not affected, and no postoperative abdomen hernia or ulceration was noted. Conclusions: The free thinned deep inferior epigastric artery perforator flap is thin and suitable for repairing extensive soft tissue defects in extremities with very good outcomes.

Active case finding with case management: the key to tackling the COVID-19 pandemic

COVID-19 was declared a pandemic by WHO on March 11, 2020, the first non-influenza pandemic, affecting more than 200 countries and areas, with more than 5·9 million cases by May 31, 2020. Countries have developed strategies to deal with the COVID-19 pandemic that fit their epidemiological situations, capacities, and values. We describe China's strategies for prevention and control of COVID-19 (containment and suppression) and their application, from the perspective of the COVID-19 experience to date in China. Although China has contained severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and nearly stopped indigenous transmission, a strong suppression effort must continue to prevent re-establishment of community transmission from importation-related cases. We believe that case finding and management, with identification and quarantine of close contacts, are vitally important containment measures and are essential in China's pathway forward. We describe the next steps planned in China that follow the containment effort. We believe that sharing countries' experiences will help the global community manage the COVID-19 pandemic by identifying what works in the struggle against SARS-CoV-2.

Frontal fibrosing alopecia shows robust T helper 1 and Janus kinase 3 skewing

BACKGROUND

Frontal fibrosing alopecia (FFA) is a scarring alopecia with unclear pathogenesis and a progressive course. The disease has a major impact on patients' quality of life and there is a lack of effective treatment to halt disease progression.

METHODS

We profiled lesional and nonlesional scalp biopsies collected in 2017 from patients with FFA (n = 12) compared with scalp biopsies from patients with alopecia areata (AA) (n = 8) and controls (n = 8) to evaluate gene and protein expression, including the primary outcome (CXCL9). We determined significant differences between biomarkers using a two-sided Student's t-test adjusting P-values by false discovery rate.

RESULTS

Significant increases were seen in CD8+ cytotoxic T cells, CD11c+ dendritic cells, CD103+ and CD69+ tissue-resident memory T cells in FFA and AA vs. control scalp (P < 0·05), with corresponding significantly upregulated granzyme B mRNA, particularly in FFA (P < 0·01). In AA, cellular infiltrates were primarily concentrated at the bulb, while in FFA these were mainly localized at the bulge. FFA demonstrated significant upregulation of T helper 1/intereferon (IFN) (IFN-γ, CXCL9/CXCL10), the Janus kinase/signal transducers and activators of transcription (JAK-STAT) pathway (STAT1, JAK3) and fibrosis-related products (vimentin, fibronectin; P < 0·05), with no concomitant downregulation of hair keratins and the T-regulatory marker, forkhead box P3, which were decreased in AA. The stem cell markers CD200 and K15 demonstrated significantly reduced expression only in FFA (P < 0·05).

CONCLUSIONS

These data suggest that follicular damage and loss of stem cells in FFA may be mediated through immune attack in the bulge region, with secondary fibrosis and reduced but still detectable stem cells. JAK/STAT-targeting treatments may be able to prevent permanent follicular destruction and fibrosis in early disease stages.

Genomic Epidemiology of SARS-CoV-2 in Guangdong Province, China

Coronavirus disease 2019 (COVID-19) is caused by SARS-CoV-2 infection and was first reported in central China in December 2019. Extensive molecular surveillance in Guangdong, China's most populous province, during early 2020 resulted in 1,388 reported RNA-positive cases from 1.6 million tests. In order to understand the molecular epidemiology and genetic diversity of SARS-CoV-2 in China, we generated 53 genomes from infected individuals in Guangdong using a combination of metagenomic sequencing and tiling amplicon approaches. Combined epidemiological and phylogenetic analyses indicate multiple independent introductions to Guangdong, although phylogenetic clustering is uncertain because of low virus genetic variation early in the pandemic. Our results illustrate how the timing, size, and duration of putative local transmission chains were constrained by national travel restrictions and by the province's large-scale intensive surveillance and intervention measures. Despite these successes, COVID-19 surveillance in Guangdong is still required, because the number of cases imported from other countries has increased.

Tracking echovirus eleven outbreaks in Guangdong, China: a metatranscriptomic, phylogenetic, and epidemiological study

In April 2019, a suspect cluster of enterovirus cases was reported in a neonatology department in Guangdong, China, resulting in five deaths. We aimed to investigate the pathogen profiles in fatal cases, the circulation and transmission pattern of the viruses by combining metatranscriptomic, phylogenetic, and epidemiological analyses. Metatranscriptomic sequencing was used to characterize the enteroviruses. Clinical and environmental surveillance in the local population was performed to understand the prevalence and genetic diversity of the viruses in the local population. The possible source(s), evolution, transmission, and recombination of the viruses were investigated by incorporating genomes from the current outbreak, from local retrospective surveillance, and from public databases. Metatranscriptomic analysis identified Echovirus 11 (E11) in three fatal cases. Seroprevalence of neutralization antibody to E11 was 35 to 44 per cent in 3–15 age groups of general population, and the viruses were associated with various clinical symptoms. From the viral phylogeny, nosocomial transmissions were identified and all E11 2019 outbreak strains were closely related with E11 strains circulating in local population 2017–19. Frequent recombination occurred among the 2019 Guangdong E11 outbreak strains and various genotypes in enterovirus B species. This study provides an example of combining advanced genetic technology and epidemiological surveillance in pathogen diagnosis, source(s), and transmission tracing during an infectious disease outbreak. The result highlights the hidden E11 circulation and the risk of viral transmission and infection in the young age population in China. Frequent recombination between Guangdong-like strains and other enterovirus genotypes also implies the prevalence of these emerging E11 strains.

Avian Influenza Virus Detection Rates in Poultry and Environment at Live Poultry Markets, Guangdong, China

We report the use of environmental samples to assess avian influenza virus activity in chickens at live poultry markets in China. Results of environmental and chicken samples correlate moderately well. However, collection of multiple environmental samples from holding, processing, and selling areas is recommended to detect viruses expected to have low prevalence.

Fasudil alleviates hepatic fibrosis in type 1 diabetic rats: involvement of the inflammation and RhoA/ROCK pathway

OBJECTIVE

Rho-associated kinases (ROCKs) are recognized to be involved in many pathophysiological processes caused by hyperglycemia. We performed experiments to evaluate the effects of fasudil, the Rho/ROCK inhibitor, on preventing hepatic fibrosis in type 1 diabetic rats and to elucidate the underlying mechanisms.

MATERIALS AND METHODS

Sprague-Dawley (SD) rats were randomly divided into five groups: normal control (NC), untreated diabetic (DM), low-dose fasudil-treated (L-Fas), high-dose fasudil-treated (H-Fas) and captopril-treated (Cap) groups. Streptozotocin was injected to establish the diabetes model. Alanine aminotransferase (ALT), aspartate aminotransferase (AST) and inflammatory factors such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), were analyzed. Hematoxylin and eosin (HE) and Masson's trichrome staining were used for histological observations. The expression of transforming growth factor-β (TGF-β1), metalloproteinase-9 (MMP-9)/tissue inhibitor of metalloproteinase-1 (TIMP-1), collagen type Iα (Coll α1), nuclear factor-kappa B (NF-κB) and ROCK-1 were measured to investigate the mechanisms involved in fibrosis.

RESULTS

The DM group exhibited hepatic fibrosis with remarkable liver damage and inflammation reaction by the activation of the NF-κB pathway. Treatment with fasudil or captopril suppressed not only the inflammation reaction but also the accumulation of the extracellular matrix due to the downregulation of TGF-β1 and MMP-9/TIMP-1, which induces the amelioration of the liver fibrosis with diabetes. Furthermore, fasudil significantly attenuated the activation of ROCK-1 and NF-κB in the livers of diabetic rats.

CONCLUSIONS

These results suggest that fasudil exert anti-inflammation actions and markedly decrease the accumulation of extracellular matrix. Fasudil is a good candidate agent for treating hepatic fibrosis in diabetes.

Examining the Effect of the Environment and Commuting Flow from/to Epidemic Areas on the Spread of Dengue Fever

Environment and human mobility have been considered as two important factors that drive the outbreak and transmission of dengue fever (DF). Most studies focus on the local environment while neglecting environment of the places, especially epidemic areas that people came from or traveled to. Commuting is a major form of interactions between places. Therefore, this research generates commuting flows from mobile phone tracked data. Geographically weighted Poisson regression (GWPR) and analysis of variance (ANOVA) are used to examine the effect of commuting flows, especially those from/to epidemic areas, on DF in 2014 at the Jiedao level in Guangzhou. The results suggest that (1) commuting flows from/to epidemic areas affect the transmission of DF; (2) such effects vary in space; and (3) the spatial variation of the effects can be explained by the environment of the epidemic areas that commuters commuted from/to. These findings have important policy implications for making effective intervention strategies, especially when resources are limited.

Detection of hepatitis E virus genotypes 3 and 4 in donkeys in northern China

BACKGROUND

Hepatitis E virus (HEV) is the causative agent of acute self-limiting hepatitis in humans in developing countries. Hepatitis E virus RNA was first detected in donkeys in Spain, but little is known about the possible presence of HEV in donkeys in China.

OBJECTIVES

To investigate the prevalence of HEV in donkeys in northern China.

STUDY DESIGN

Investigation of the prevalence of HEV in donkeys using serological, molecular and phylogenetic approaches.

METHODS

A total of 401 donkey serum specimens were tested for serological and molecular detection of HEV via enzyme-linked immunosorbent assay and quantitative reverse transcription polymerase chain reaction. The amplified products were cloned in pMD18-T vector and sequenced. The alignment and phylogenetic analysis of partial HEV ORF2 genes were compared with the corresponding sequences of the obtained HEV representative strains.

RESULTS

Serological results showed that 49 donkeys (12.22%, 95% CI: 9.18-15.83%) were positive for anti-HEV-specific antibodies, and 17 donkeys (4.24%, 95% CI: 2.49-6.70%) were positive for HEV viral RNA. On the basis of sequence alignment and phylogenetic analysis, all isolated HEV strains belonged to genotype 3 (HEV-3) or HEV-4, sharing more than 76.2-96.3% identities with 67 other HEV representative strains of HEV-1 to HEV-8.

MAIN LIMITATIONS

Further studies about the prevalence of HEV in organs or faecal samples from donkeys are needed to evaluate the possible role of HEV reservoir and to determine the risk factors associated with the transmission of this zoonotic virus in donkeys in China.

CONCLUSIONS

This is the first report documenting the molecular analysis of donkey HEV strains worldwide and the serological evidence of HEV infection in donkeys in northern China. The results suggest that young donkeys are more susceptible to HEV infection compared with older donkeys. Further investigation is required to determine whether donkeys should be considered reservoirs for zoonotic HEV. The Summary is available in Chinese - see Supporting information.

Poor survival after resection of early gastric cancer: extremes of survivorship analysis reveal distinct genomic profile

A subset of patients with early gastric cancer demonstrate early recurrence and poor survival despite margin-negative resection. This study used an extremes-of-survivorship approach to identify an association between TP53 hotspot mutations co-occurring with loss of heterozygosity and unexpectedly poor survival in early gastric cancer. This distinct genomic profile may be a novel biomarker of poor survival in patients with completely resected early gastric cancer, and warrants large-scale validation. Promising, validation needed.

Study on the relationship between changes of immune cells and TNF-α in peripheral blood of patients with multidrug-resistant and extensively drug-resistant tuberculosis

OBJECTIVE

To investigate the relationship between changes in CD4- and CD8-positive immune cells and TNF-α in the peripheral blood of patients affected by multidrug-resistant and extensively drug-resistant tuberculosis.

PATIENTS AND METHODS

179 patients suffering from tuberculosis treated in the Chest Hospital of Hebei from April 2010 to December 2015 were selected for the study. There were 47 cases affected by drug-resistant tuberculosis and 132 cases affected by non-drug-resistant tuberculosis. The control group included 183 healthy subjects examined during the same period. ELISA was used to compare and analyze serum levels of TNF-α, CD4- and CD8-positive cell levels, and CD4/CD8 ratio in the two groups.

RESULTS

CD4- and CD8-positive cell count, CD4/CD8 ratio, and serum TNF-a were significantly higher in patients with drug-resistant tuberculosis compared with healthy controls and the non-drug-resistant tuberculosis patients (p < 0.05). There was a positive correlation between TNF-α level and CD4/CD8 ratio (r=0.892, p < 0.05). Before treatment, the differences in the levels of TNF-a in the different groups of drug-resistant patients were insignificant (p >0.05). After treatment, the levels of TNF-a in the different groups of drug-resistant patients were decreased, except for patients with extensively drug-resistant tuberculosis, whose levels were significantly decreased compared with before treatment (t = 0.648, p>0.05). The differences in the levels of TNF-α in the other groups of patients before and after treatment were statistically significant (t = 8.497, 6.258, 5.346, p < 0.05, fully sensitive tuberculosis single drug-resistant tuberculosis, multidrug-resistant tuberculosis, respectively).

CONCLUSIONS

The level of TNF-α plays a critical role in the evaluation of the severity of patients with drug-resistant tuberculosis and it has a clinical value.

Epidemiology, evolution and transmission of human metapneumovirus in Guangzhou China, 2013-2017

Human metapneumovirus (hMPV), first identified in 2001, is a major viral respiratory pathogen that worldwide reported. Fundamental questions concerning the dynamics of viral evolution and transmission at both regional and global scales remain unanswered. In this study, we obtained 32 G gene and 51 F gene sequences of hMPV in Guangzhou, China in 2013–2017. Temporal and spatial phylogenetic analyses were undertaken by incorporating publicly available hMPV G gene (978) and F gene (767) sequences. The phylogenetic results show different global distribution patterns of hMPV before 1990, 1990–2005, and 2006–2017. A sharply increasing hMPV positive rate (11%) was detected in Guangzhou 2017, mainly caused by the B1 lineage of hMPV. A close phylogenetic relation was observed between hMPV strains from China and Japan, suggesting frequent hMPV transmissions between these regions. These results provide new insights into hMPV evolution, transmission, and spatial distribution and highlight Asia as a new epicenter for viral transmission and novel variant seeding after the year 2005. Conducting molecular surveillance of hMPV in Asian countries is critical for understanding the global circulation of hMPV and future vaccine design.

The oral Janus kinase/spleen tyrosine kinase inhibitor ASN002 demonstrates efficacy and improves associated systemic inflammation in patients with moderate-to-severe atopic dermatitis: results from a randomized double-blind placebo-controlled study

BACKGROUND

ASN002 is an oral dual inhibitor of Janus kinase and spleen tyrosine kinase, which are involved in the pathogenesis of atopic dermatitis (AD) through their regulatory role on T helper (Th)1, Th2 and Th17/Th22 pathways.

OBJECTIVES

The objectives of this study were to evaluate the efficacy, safety, pharmacokinetics and effects on systemic biomarkers of ASN002 in patients with moderate-to-severe AD. Methods A total of 36 patients with moderate-to-severe AD were randomized (3 : 1) to ASN002 or placebo in the phase Ib study. Three dosage cohorts were studied over a 28-day period (20 mg, 40 mg and 80 mg once daily).

RESULTS

ASN002 was superior to placebo for the proportion of patients achieving Eczema Area and Severity Index (EASI) 50 (20 mg 20%, P = 0·93; 40 mg 100%, P = 0·003; 80 mg 83%, P = 0·03; placebo 22%), EASI 75 (20 mg 0%, P = 0·27; 40 mg 71%, P = 0·06; 80 mg 33%, P = 0·65; placebo 22%) and in change from baseline in pruritus (20 mg -1·3 ± 2·1, P = 0·81; 40 mg -3·1 ± 2·7, P = 0·27; 80 mg -4·7 ± 2·1, P = 0·01; placebo -1·6 ± 1·8). Adverse events were generally mild and similar across all groups. ASN002 showed dose-dependent plasma exposure with low interpatient variability, significantly downregulated several serum biomarkers involved in Th1, Th2 and Th17/Th22 immunity, and decreased the atherosclerosis-associated biomarker E selectin/SELE.

CONCLUSIONS

In patients with moderate-to-severe AD, ASN002 showed strong efficacy with rapid onset of action and associated improvements in systemic inflammation.

NKAP plays an oncogenic function partly through AKT signaling pathway in hepatocellular carcinoma

NF-kB activating protein (NKAP) is a highly conserved protein involved in transcriptional repression, immune cell development, maturation, T cell acquisition of functional competency and maintenance of hematopoiesis. Here we first explore the function of NKAP in hepatocellular carcinoma (HCC). We found that NKAP was highly expressed in HCC tissues and associated with a poor patient survival. CCK8 assay showed that NKAP knockdown significantly decreased cell viability of HuH7 and Hep3B HCC cell lines. Cell invasion, tested by transwell assays, was significantly inhibited by NKAP knockdown in HuH7 and Hep3B cells (P<0.05). Percentage of cell apoptosis was significantly increased by NKAP knockdown in HuH7 cells (6.5% to 12.5%) and in Hep3B cells (8.3% to 27.3%). Furthermore, western blot results indicated that NKAP silence upregulated the expression of pro-apoptotic proteins Bax and Caspase3-P17 while downregulated anti-apoptotic protein Bcl2. Finaly, AKT signaling pathway was evaluated to reveal the underlying mechanism of NKAP in HCC cells. It was suggested that NKAP knockdown decreased the phosphorylation level of AKT and the expression of its downstream members p70S6K and Cyclin D1. Furthermore, we demonstrated that NKAP knockdown also played an oncogenic role in human gastric cancer AGS and MKN45 cells. In conclusion, for the first time our study reveals that NKAP promotes the proliferation and invasion in HCC cell lines at least partly through AKT signaling pathway.