Phylogenetic and antigenic analysis of HA gene of influenza virus B (Victoria) in Beijing during 2021-2022 surveillance season / 中华微生物学和免疫学杂志

Objective:To investigate the phylogenetic and antigenic characteristics of hemagglutinin (HA) gene of influenza B/Victoria lineage (BV) viruses in Beijing during the 2021-2022 influenza surveillance season, and to analyze whether the circulating BV viruses match the vaccine strain.Methods:Pharyngeal swab specimens from influenza like-illness (ILI) cases in the 2021-2022 influenza surveillance season were collected from surveillance network labs in Beijing and cultured in MDCK cells and chicken embryo to isolate BV viruses. Nucleic acids of the viruses were extracted, and the HA gene was amplified and sequenced. The nucleotide and amino acid sequence identity of the HA gene was analyzed using MEGA5.0 software. A phylogenetic tree of HA gene was constructed using the maximum likelihood method. The N-glycosylation sites in HA were predicted online. Three-dimensional structure of HA was constructed using SWISS-MODEL homologous modeling. Hemagglutination inhibition (HI) test was performed to analyze the antigenicity of BV viruses.Results:A total of 402 BV viruses were collected and 58 strains with full-length HA gene sequences were chosen for further analysis. Compared with the HA gene of this year′s vaccine strain (B/Washington/02/2019), there were 27 amino acid mutations, 11 of which were located in four different antigenic determinants. The phylogenetic analysis revealed that three subgroups of 1A.3, 1A.3a1, and 1A.3a2 co-circulated in Beijing with 54 strains (54/58, 93.10%) clustered to the Clade 1A.3a2, two strains (2/58, 3.45%) clustered to the Clade 1A.3a1, and two strains (2/58, 3.45%) in the same subgroup (Clade 1A.3) as the vaccine component BV strain in 2021-2022. Compared with the vaccine strain (B/Washington/02/2019), two BV strains had an additional N-glycosylation site at residue 197, while the other 56 strains showed no change in N-glycosylation sites. Antigenic analysis showed that 35 BV strains (35/58, 60.34%) were antigenically similar to the vaccine strain and 23 strains (23/58, 39.66%) were low-response strains.Conclusions:Three subgroups of BV viruses co-circulated in Beijing during the 2021-2022 influenza surveillance season. The predominant subgroup was Clade 1A.3a2 (93.10%), showing a certain genetic distance with the vaccine strain (B/Washington/02/2019). Nearly 40% (39.66%) of the viruses were low-response strains. This study indicated that continuous monitoring of the variations of influenza epidemic strains and timely providing laboratory basis for screening vaccine component strains were the basic technical guarantee for coping with influenza pandemic.

SARS-CoV-2 containment was achievable during the early stage of the pandemic: a retrospective modelling study of the Xinfadi outbreak in Beijing

Prior to the emergence of the Omicron variant, many cities in China had been able to maintain a "Zero-COVID" policy. They were able to achieve this without blanket city-wide lockdown and through widespread testing and an extensive set of nonpharmaceutical interventions (NPIs), such as mask wearing, contact tracing, and social distancing. We wanted to examine the effectiveness of such a policy in containing SARS-CoV-2 in the early stage of the pandemic. Therefore, we developed a fully stochastic, spatially structured, agent-based model of SARS-CoV-2 ancestral strain and reconstructed the Beijing Xinfadi outbreak through computational simulations. We found that screening for symptoms and among high-risk populations served as methods to discover cryptic community transmission in the early stage of the outbreak. Effective contact tracing could greatly reduce transmission. Targeted community lockdown and temporal mobility restriction could slow down the spatial spread of the virus, with much less of the population being affected. Population-wide mass testing could further improve the speed at which the outbreak is contained. Our analysis suggests that the containment of SARS-CoV-2 ancestral strains was certainly possible. Outbreak suppression and containment at the beginning of the pandemic, before the virus had the opportunity to undergo extensive adaptive evolution with increasing fitness in the human population, could be much more cost-effective in averting the overall pandemic disease burden and socioeconomic cost.

Assessing the feasibility of sustaining a 'Zero-COVID' policy in China in the era of highly transmissible variants

We developed a spatially structured, fully stochastic, individual-based SARS-CoV-2 transmission model to evaluate the feasibility of sustaining SARS-CoV-2 local containment in mainland China considering currently dominant Omicron variants, Chinas current immunization level, and non-pharmaceutical interventions (NPIs). We also built a statistical model to estimate the overall disease burden under various hypothetical mitigation scenarios. We found that due to high transmissibility, neither Omicron BA.1 or BA.2 could be contained by Chinas pre-Omicron NPI strategies which were successful prior to the emergence of the Omicron variants. However, increased intervention intensity, such as enhanced population mobility restrictions and multi-round mass testing, could lead to containment success. We estimated that an acute Omicron epidemic wave in mainland China would result in significant number of deaths if China were to reopen under current vaccine coverage with no antiviral uptake, while increasing vaccination coverage and antiviral uptake could substantially reduce the disease burden. As Chinas current vaccination has yet to reach high coverage in older populations, NPIs remain essential tools to maintain low levels of infection while building up protective population immunity, ensuring a smooth transition out of the pandemic phase while minimizing the overall disease burden.

Analysis of emm genotypes and drug susceptibility characteristic variations of Group A Streptococcus in children in Beijing / 中华实用儿科临床杂志

Objective:To clarify the M protein ( emm gene) types and drug susceptibility characteristic variations of Group A Streptococcus (GAS) in children in Beijing. Methods:The GAS strains isolated from throat swab samples of children diagnosed with scarlet fever and pharyngeal infection in scarlet fever etiology surveillance sentinel hospitals in 16 districts of Beijing in 2018, 2019 and 2021 were analyzed retrospectively.PCR amplification and sequencing were used for emm genotyping, and the minimum inhibitory concentrations (MIC) of 10 antibiotics were determined by the broth microdilution method.The data were analyzed using χ2 test and Fisher′ s exact method between groups. Results:A total of 557 GAS strains were collected, and 11 emm genotypes ( emm1, emm3, emm4, emm6, emm11, emm12, emm22, emm75, emm89, emm128, and emm212) were detected.Of 557 strains, 238 trains were of emm1 type (42.73%), 271 strains were of emm12 type (48.65%) and 48 strains were of other emm types (8.62%). The detection rates of emm1, emm12 and other emm type genes in 2018, 2019, and 2021 were [37.50% (105/280 strains), 57.14% (160/280 strains), 5.36% (15/280 strains)], [49.05% (129/263 strains), 39.54% (104/263 strains), 11.41% (30/263 strains)], and [28.57% (4/14 strains), 50.00% (7/14 strains), 21.43% (3/14 strains)], respectively.In children infected with emm12 in 2018 and 2019, there were more children under 6 years old than children over 6 years old (62.50% vs.46.88%, 46.36% vs.30.36%) (χ 2=7.182, 6.973; all P<0.05). Drug susceptibility testing results suggested that 225 randomly selected GAS strains were all 100.00% sensitive to 7 antibiotics including Penicillin, Levofloxacin, Meropenem, Linezolid, Cefotaxime, Cefepime and Vancomycin.The rates of resistance to Erythromycin, Tetracycline and Clindamycin were [88.57% (93/105 strains), 87.62% (92/105 strains), 86.67% (91/105 strains)], and [94.34% (100/106 strains), 94.34% (100/106 strains), 87.74% (93/106 strains)] in 2018 and 2019, respectively.The test strains were 100.00% (14/14 strains) resistant to the above 3 antibiotics in 2021.MIC 50 and MIC 90 values of Penicillin in 2018, 2019, and 2021 were (0.03 mg/L, 0.03 mg/L), (0.03 mg/L, 0.06 mg/L), and (0.06 mg/L, 0.06 mg/L), respectively.Among 225 GAS strains, 207 strains had drug resistance and were resistant to more than one drug.Specifically, 94.69% (196/207 strains) were resistant to Erythromycin, Tetracycline and Clindamycin.About 4.35% (9/207 strains) were resistant to both Erythromycin and Clindamycin.A total of 0.97% (2/207 strains) were resistant to Erythromycin and Tetracycline. Conclusions:The emm genotypes of GAS in children in Beijing are diverse in 2018, 2019 and 2021.The dominant genotypes are emm12 and emm1, and emm12 is the main epidemiological type.GAS strains maintain highly resistant to Erythromycin, Clindamycin and Tetracycline, and sensitive to Penicillin and other antibiotics.However, MIC 50 and MIC 90 of Penicillin shows an ascending trend.

Effect of exosomes from adult human liver-derived stem cells on concanavalin A-induced acute liver injury in mice / 临床肝胆病杂志

Objective To investigate the protective effect of adult human liver-derived stem cell exosomes (HLSC-exo) intravenously injected at different time points against acute liver injury induced by concanavalin A (ConA) in mice. Methods HLSC-exo was extracted by differential centrifugation. Western blot was used to measure the expression of the marker proteins CD9 and CD63, and nanoparticle tracking analysis was used to investigate particle size distribution. A total of 56 male C57BL/6 mice were randomly divided into blank control group, ConA model group, and HLSC-exo treatment group. The ConA model group and the HLSC-exo treatment group were further divided into 3-, 6-, and 12-hour subgroups according to the interval between phosphate buffer or HLSC-exo injection and ConA injection. The serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), tumor necrosis factor-α (TNF-α), and interleukin-10 (IL-10) were measured, and the gross morphology and histopathology of the liver were compared between groups. A one-way analysis of variance was used for comparison of continuous data between multiple groups, and the least significant difference t -test was used for further comparison between two groups. Results HLSC-exo was a membranous vesicle with a diameter of 90-110 nm, with a clear saucer-like structure under an electron microscope and marked expression of its specific marker proteins CD9 and CD63. In the blank control group, the levels of ALT and AST were 31.81±6.74 U/L and 69.75±8.30 U/L, respectively. Compared with the blank control group, the 3-, 6-, and 12-hour ConA model groups had significant increases in the levels of ALT and AST (all P < 0.001); compared with the 3-and 6-hour ConA model groups, the 3-and 6-hour HLSC-exo treatment groups had significant reductions in the levels of ALT and AST (225.58±115.59 U/L vs 1989.32±347.67 U/L, 1174.71±203.30 U/L vs 2208.33±349.96 U/L, 303.53±126.68 U/L vs 2534.27±644.72 U/L, 1340.70±262.56 U/L vs 2437.13±288.13 U/L, all P < 0.001); compared with the 6-hour HLSC-exo treatment group, the 3-hour HLSC-exo treatment group had significantly greater reductions ( P < 0.001). In the blank group, the levels of IL-10 and TNF-α were 313.51±10.97 pg/ml and 476.05±7.31 pg/ml, respectively. Compared with the blank control group, the 3-, 6-, and 12-hour ConA model groups had a significant reduction in the level of IL-10 (all P < 0.001); compared with the 3-and 6-hour ConA model groups, the 3-and 6-hour HLSC-exo treatment groups had a significant increase in the level of IL-10(331.61±10.46 pg/ml vs 266.20±8.15 pg/ml, 288.13±10.74 pg/ml vs 264.41±9.12 pg/ml, both P < 0.001); compared with the 6-hour HLSC-exo treatment group, the 3-hour HLSC-exo treatment group had a significantly greater increase ( P < 0.001). Compared with the blank control group, the 3-, 6-, and 12-hour ConA model groups had a significant increase in the level of TNF-α (all P < 0.001); compared with the 3-and 6-hour ConA model groups, the 3-and 6-hour HLSC-exo treatment groups had a significant reduction in the level of TNF-α (478.26±12.99 pg/ml vs 551.31±17.70 pg/ml, 515.58±7.18 pg/ml vs 556.21±11.15 pg/ml, both P < 0.001); compared with the 6-hour HLSC-exo treatment group, the 3-hour HLSC-exo treatment group had a significantly greater reduction ( P < 0.001). Compared with the 3-and 6-hour ConA model groups in terms of the gross morphology and histopathology of the liver, the 3-and 6-hour HLSC-exo treatment groups had a significant reduction in the degree of hepatocyte necrosis, and the 3-hour HLSC-exo treatment group had a basically complete lobular structure, with sporadic spotty necrosis; the 12-hour HLSC-exo treatment group had no significant improvement in hepatocyte necrosis compared with the 12-hour ConA model group. Conclusion Intravenous injection of adult HLSC-exo can alleviate acute liver injury induced by ConA in mice, and injection at 3 hours in advance has the most significant protective effect. Regulation of cytokines is one of the important mechanisms for HLSC-exo to alleviate liver injury.

Construction of a new patient-derived xenograft model of human liver cancer in mice with normal immunity / 临床肝胆病杂志

Objective To establish a new patient-derived xenograft (PDX) model of human liver cancer by inoculating the complex of human primary liver cancer cells and a novel microcarrier (microcarrier 6) into mice with normal immune function. Methods Primary liver cancer cells were isolated and extracted from the fresh human liver cancer tissue of five patients and were then co-cultured with microcarrier 6 to construct a three-dimensional tumor cell culture model in vitro . According to the type of graft, 75 male C57BL/6 mice were divided into cell control group, microcarrier control group, and experimental group (each sample corresponded to three groups, with 15 groups in total and 5 mice in each group). The liver cancer cell-microcarrier complex was implanted into the mice by subcutaneous inoculation, and tumor formation time, tumor formation rate, and histopathological manifestations were observed. The Fisher's exact test was used for comparison of categorical data between two groups. Results As for the liver cancer cells from the five patients, tumor formation was observed in the mice corresponding to three patients. In these three experiments, tumor formation was not observed in the control groups and was only observed in the experimental groups, and 12 of the 15 mice in the experimental groups had successful tumor formation, with a tumor formation rate as high as 80%, which was significantly different from that in the cell control groups and the microcarrier control groups (all P < 0.05). The tumor formation time was 5-7 days; the xenograft tumor grew rapidly, and HE staining showed nested or flaky cells with obvious heteromorphism, with the presence of pathological mitosis; immunohistochemical staining showed positive CK8/18, Hep, and Gpc-3, which was in accordance with the characteristics of human liver cancer cells. Conclusion This experiment successfully establishes a new PDX model of human liver cancer based on the complex of microcarrier 6 and human primary liver cancer cells in mice with normal immunity. This model can be used to better elucidate the mechanism of the development and progression of liver cancer in the body with normal immunity, and besides, it also provides a new animal model with higher value for the precise treatment of liver cancer.

Analysis of clinical characteristics of 43 patients with pulmonary mycosis diagnosed by pathology / 中华危重病急救医学

Objective:To observe the etiological distribution, clinical presentations and imaging features of pulmonary mycosis that is diagnosed by pathology.Methods:The etiological distribution, clinical presentations and imaging features of patients with pulmonary mycosis, who were collected in the Affiliated Hospital of Jining Medical University from January 2018 to July 2020, were retrospectively analyzed. The diagnosis of all the patients were confirmed by pathological examination, of lung or bronchi tissue that were obtained through operation, bronchoscope or percutaneous lung puncture biopsy.Results:There were 26 patients' (60.47%, 26/43) pathological specimens were obtained by operation, 14 cases (32.56%, 14/43) were obtained by bronchoscope, and 3 cases (6.98%, 3/43) were obtained by percutaneous lung puncture biopsy. Of the 43 patients who were diagnosed pulmonary mycosis by pathology, 27 patients (62.79%, 27/43) suffered from pulmonary aspergillosis, 11 patients (25.58%, 11/43) suffered from pulmonary cryptococcosis, 3 patients (6.98%, 3/43) suffered from pulmonary mucormycosis, and 2 patients (4.65%, 2/43) suffered from pulmonary candidiasis. There were 27 patients (62.79%, 27/43) with pulmonary fungal disease complicating risk factors of fungal infection, including diabetes mellitus (23.26%,10/43), malignant tumor (16.28%, 7/43), bronchiectasis (9.30%, 4/43), hepatitis B virus (HBV) carrier (6.98%, 3/43), taking glucocorticoids (4.65%, 2/43), pulmonary tuberculosis (4.65%, 2/43), and chemotherapy following colon carcinoma operation (2.33%, 1/43). The common clinical presentations included cough (55.81%, 24/43), expectoration (48.84%, 21/43), hemoptysis (37.21%, 16/43), fever (20.93%, 9/43), gasping (18.60%, 8/43), chest pain (16.28%, 7/43), and hoarseness (3.13%, 1/43). Imaging features of chest included lung nodes in 20 cases (46.51%, 20/43), vascular welt sign in 12 cases (27.91%, 12/43), exudative process in 10 cases (23.26%, 10/43), lung mass or consolidation in 8 cases (18.60%, 8/43), cavitary lesions in 7 cases (16.28%, 7/43), thicken bronchus wall and narrow lumina in 6 cases (13.95%, 6/43), air crescent in 5 cases (11.63%, 5/43).Conclusions:The pulmonary aspergillosis and cryptococcosis are mainly in pulmonary mycosis diagnosed by pathology. The common complications are diabetes mellitus and malignant tumor. The common clinical presentations are cough, expectoration, and hemoptysis. The main imaging features of chest are lung nodes and vascular welt sign can be found in most of pulmonary cryptococcosis.

Multimodal ultrasonic diagnosis of breast fibromatosis originating from breast parenchyma / 中国医师杂志

Objective:To analyze the imaging characteristics of invasive fibromatosis from breast parenchyma, and to explore the clinical value of multimodal ultrasound.Methods:The two-dimensional, color Doppler and elastic imaging sonographic manifestations and pathological features of 12 cases of breast invasive fibromatosis included in the Affiliated Hospital of Jining Medical College from October 2015 to October 2020 were studied retrospectively.Results:Two dimensional ultrasound showed that 12 cases of breast invasive fibromatosis grew in parallel, with different sizes, unclear boundary and no complete capsule. The edge morphology of 7 cases (7/12) showed crab foot like changes; The tumor showed solid heterogeneous hypoechoic, punctate hyperechoic in 3 cases (3/12), and echo attenuation behind the tumor in 3 cases (3/12); The blood flow in the tumor was mainly grade 1-2 (9/12). Twelve tumors were examined quantitatively by virtual touch tissue quantifification. The shear wave velocity was (3.08±0.75)m/s. The diagnostic accuracy of multimodal ultrasound in invasive fibromatosis of breast (10/12) was significantly higher than that of conventional ultrasound (3/12, χ 2=8.224, P=0.004). The gross manifestation of the tumor: the section was gray or gray yellow, with unclear boundary and no capsule; Microscopic findings: fascicular fibroblasts and myofibroblasts proliferated, accompanied by varying degrees of glassy degeneration, acellular atypia, nuclear division and necrosis. Conclusions:Conventional ultrasound is difficult to distinguish invasive fibromatosis and malignant tumor of breast, and its ultrasonic manifestations are closely related to pathological features. The combined application of multimodal ultrasound can significantly improve the diagnostic coincidence rate of the disease and has high clinical application value.

A population-based seroprevalence survey of severe acute respiratory syndrome coronavirus 2 infection in Beijing, China

BACKGOUNDThe spread of Coronavirus Disease 2019 (COVID-19) had been controlled in China. The seroprevalence of COVID-19 in Beijing has not been evaluated. METHODSIn April, residents in Beijing were randomly enrolled. Blood samples were collected and antibodies to SARS- CoV-2 were tested by two colloidal gold kits. All colloidal gold positive serums were then tested by Micro- neutralization assay. RESULTSNone of 2,184 residents participated was tested positive by micro-neutralization assay. The seroprevalence of COVID-19 in Beijing was estimated < 0.17%. CONCLUSIONSThe seroprevalence of COVID-19 was low in April suggesting that community-wide spread was prevented in Beijing.

Human coronavirus data from four clinical trials of masks and respirators.

There are few published data on the efficacy of masks or respirators against coronavirus infections. This is an important research question to inform the response to the COVID-19 epidemic. The transmission modes of human coronaviruses are similar, thought to be by droplet, contact, and sometimes airborne routes. There are several randomized clinical trials of masks and respirators, but most used clinical endpoints or tested only for influenza. In four trials that we conducted, we tested for human coronaviruses, but only composite viral endpoints were reported in the trials. We reviewed and analyzed the coronavirus data from four of our trials. Laboratory-confirmed coronavirus infections were identified in our community household trial (one case), health worker trials (eight cases), and trial of mask use by sick patients (19 cases). No coronavirus infections were transmitted in households to parents who wore P2 or surgical masks, but one child with coronavirus infection transmitted infection to a parent in the control arm. No transmissions to close contacts occurred when worn by sick patients with coronavirus infections. There was a higher risk of coronavirus infection in HCWs who wore a mask compared to a respirator, but the difference was not statistically significant. These are the only available clinical trial data on coronavirus infections associated with mask or respirator use. More clinical trials are needed to assess the efficacy of respiratory protection against coronavirus infections.

Neutralizing Antibodies Responses to SARS-CoV-2 in COVID-19 Inpatients and Convalescent Patients

BackgroundCOVID-19 is a pandemic with no specific antiviral treatments or vaccines. The urgent needs for exploring the neutralizing antibodies from patients with different clinical characteristics are emerging. MethodsA total of 117 blood samples were collected from 70 COVID-19 inpatients and convalescent patients. The presence of neutralizing antibody was determined with a modified cytopathogenic assay based on live SARS-CoV-2. The dynamics of neutralizing antibody levels at different with different clinical characteristics were analyzed. ResultsThe seropositivity rate reached up to 100.0% within 20 days since onset, and remained 100.0% till day 41-53. The total GMT was 1:163.7 (95% CI, 128.5 to 208.6), and the antibody level was highest during day 31-40 since onset, and then decreased slightly. Individual differences in changes of antibody levels were observed among 8 representative convalescent patients. In multivariate GEE analysis, patients at age of 31-60 and 61-84 had a higher antibody level than those at age of 16-30 ({beta}=1.0518, P=0.0152; {beta}=1.3718, P=0.0020). Patients with a worse clinical classification had a higher antibody titer ({beta}=0.4639, P=0.0227). ConclusionsThe neutralizing antibodies were detected even at the early stage of disease, and a significant response showed in convalescent patients. Moreover, changes on antibody levels ware individual specific.

Highly accurate and sensitive diagnostic detection of SARS-CoV-2 by digital PCR

BACKGROUNDThe outbreak of COVID-19 caused by a novel Coronavirus (termed SARS-CoV-2) has spread to over 140 countries around the world. Currently, reverse transcription quantitative qPCR (RT-qPCR) is used as the gold standard for diagnostics of SARS-CoV-2. However, the positive rate of RT-qPCR assay of pharyngeal swab samples are reported to vary from 30[~]60%. More accurate and sensitive methods are urgently needed to support the quality assurance of the RT-qPCR or as an alternative diagnostic approach. METHODSWe established a reverse transcription digital PCR (RT-dPCR) protocol to detect SARS-CoV-2 on 194 clinical pharyngeal swab samples, including 103 suspected patients, 75 close contacts and 16 supposed convalescents. RESULTSThe limit of blanks (LoBs) of the RT-dPCR assays were [~]1.6, [~]1.6 and [~]0.8 copies/reaction for ORF 1ab, N and E genes, respectively. The limit of detection (LoD) was 2 copies/reaction. For the 103 fever suspected patients, the sensitivity of SARS-CoV-2 detection was significantly improved from 28.2% by RT-qPCR to 87.4% by RT-dPCR. For close contacts, the suspect rate was greatly decreased from 21% down to 1%. The overall sensitivity, specificity and diagnostic accuracy of RT-dPCR were 90%, 100% and 93 %, respectively. In addition, quantification of the viral load for convalescents by RT-dPCR showed that a longer observation period was needed in the hospital for elderly patients. CONCLUSIONRT-dPCR could be a confirmatory method for suspected patients diagnosed by RT-qPCR. Furthermore, RT-dPCR was more sensitive and suitable for low viral load specimens from the both patients under isolation and those under observation who may not be exhibiting clinical symptoms.

Early evaluation of the Wuhan City travel restrictions in response to the 2019 novel coronavirus outbreak

Respiratory illness caused by a novel coronavirus (COVID-19) appeared in China during December 2019. Attempting to contain infection, China banned travel to and from Wuhan city on 23 January and implemented a national emergency response. Here we evaluate the spread and control of the epidemic based on a unique synthesis of data including case reports, human movement and public health interventions. The Wuhan shutdown slowed the dispersal of infection to other cities by an estimated 2.91 days (95%CI: 2.54-3.29), delaying epidemic growth elsewhere in China. Other cities that implemented control measures pre-emptively reported 33.3% (11.1-44.4%) fewer cases in the first week of their outbreaks (13.0; 7.1-18.8) compared with cities that started control later (20.6; 14.5-26.8). Among interventions investigated here, the most effective were suspending intra-city public transport, closing entertainment venues and banning public gatherings. The national emergency response delayed the growth and limited the size of the COVID-19 epidemic and, by 19 February (day 50), had averted hundreds of thousands of cases across China. One sentence summaryTravel restrictions and the national emergency response delayed the growth and limited the size of the COVID-19 epidemic in China.

Analysis of the prevalence and risk factors of goiter among children aged 8 to 10 years old in Beijing in 2018 / 中华地方病学杂志

Objective:To analyze the prevalence of goiter among children aged 8 to 10 years old in Beijing and study the influencing factors of goiter in children.Methods:In 16 districts of Beijing, each district was divided into 5 sampling districts according to east, west, south, north and middle locations in 2018. One town/street was selected from each sampling district, one primary school was selected from each town/street, and 40 non-boarding students aged 8 to 10 years old were selected from each primary school. The size of thyroid was measured by B-ultrasound method, the volume of thyroid was calculated and whether goiter or not was determined according to the "Diagnostic Criteria for Endemic Goiter". Random urine samples were collected, urinary iodine was detected by arsenic-cerium catalytic spectrophotometry. Height and weight were measured, body mass index (BMI) was calculated, and the correlation of thyroid volume with height and weight was analyzed.Results:A total of 3 268 children were surveyed, in which 154 children with goiter; the goiter rate was 4.7%. The goiter rate in girls [5.7% (93/1 641)] was higher than that in boys [3.7% (61/1 627), χ 2 = 6.694, P < 0.05]. The goiter rates of children aged 8, 9 and 10 years old were 4.3% (15/346), 5.5% (85/1 534) and 3.9% (54/1 388), respectively, there was no significant difference between the ages (χ 2 = 4.544, P > 0.05). The median of urinary iodine in children was 175.3 μg/L, which was in an iodine appropriate level. The thyroid volumes of children aged 8, 9 and 10 years old were positively correlated with height and weight ( r = 0.143, 0.225, 0.323, 0.338, 0.321, 0.346, P < 0.01). Conclusion:The goiter rate of children in Beijing is high, children's thyroid volume is greatly affected by height and weight, and it is recommended to consider the influence of height and weight when study the diagnostic criteria of children's goiter.

The Influence of Facial Asymmetry on Stress Distributions in Temporomandibular Joints for Patients with Mandibular Prognathism / 医用生物力学

Objective To explore the effects of facial asymmetry on stress distributions in temporomandibular joints (TMJs) for patients with mandibular prognathism. Methods Eight 3D maxillofacial models were established in MIMICS based on cone-beam CT of 4 mandibular prognathism patients with asymmetry and 4 mandibular prognathism patients without asymmetry. Muscle forces and boundary conditions corresponding to the unilateral occlusion (unilateral molar chewing) were applied on the models in ABAQUS. The maximum and the minimum principal stresses of TMJ were chosen for analysis. Results There were significant differences in the maximum and minimum principal stresses at the condyles between the mandibular prognathism patients with and without facial asymmetry under unilateral occlusions (P<0-05). Compared with patients without facial asymmetry, the stresses on the condyle in patients with asymmetry increased by 2-3 times, and the stresses on articular fossa increased by 5-7 times. Among the mandibular prognathism patients with asymmetry, the stresses of the ipsilateral TMJ in patients with temporomandibular disorder (TMD) were significantly higher than those in patients without TMD. Conclusions Facial asymmetry increased the stresses of the articular fossa and condyle in patients with mandibular prognathism. TMD would cause greater stresses in ipsilateral TMJ of the mandibular prognathism patient with asymmetry. Therefore, different treatment strategies should be considered for mandibular prognathism with facial asymmetry.

Pathogenic surveillance and related factors on bacillary dysentery in Beijing, 2008-2017 / 中华流行病学杂志

Objective To analyze the pathogenic surveillance programs and related factors on bacillary dysentery in Beijing,2008-2017,to provide evidence for the practices of diagnosis,treatment and prevention of the disease.Methods Analysis was conducted on surveillance data of bacillary dysentery,collected from the surveillance areas of national bacillary dysentery in Beijing.Shigella positive rate of stool samples were used as the gold standard while detection rate of Shigella,diagnostic accordance rate and resistance were computed on data from the surveillance programs.Chi-square test was used to compare the rates and unconditional logistic regression was used to analyze the related factors of Shigella infection.Results Both the reported incidence rate on bacillary dysentery and detection rate of Shigella in diarrhea patients showed significantly decreasing trend,from 2008 to 2017.The accordance rate of bacillary dysentery was only 7.80％ (111/1 423).Shigella sonnei was the most frequently isolated strain (73.95％,159/215) followed by Shigella flexnery.Results from the multivariate logistic regression of Shigella positive rate revealed that among those patients who were routine test of stool positive vs.routine test of stool positive (OR=1.863,95％CI:1.402-2.475),onset from July to October vs.other months' time (OR=7.271,95％CI:4.514-11.709) temperature ≥38 ℃ vs.temperature ＜38 ℃ (OR=4.516,95％CI:3.369-6.053) and age from 6 to 59 years old vs.other ages (OR =1.617,95 ％ CI:1.085-2.410),presenting higher positive detection rates of Shigella from the stool tests.The resistant rates on ampicillin and nalidixic acid were 97.57％ (201/206) and 94.90％ (186/196),both higher than on other antibiotics.The resistant rates on ciprofloxacin (16.33％,32/196),ofloxacin (9.57％,11/115) and on amoxilin (15.05％,31/206) were relatively low.The resistant rate appeared higher on Shigellaflexnery than on Shigella sonnei.The proportion of strains with resistance on 3 more drugs,was 30.00％ (21/70).Conclusions The diagnostic accordance rate of bacillary dysentery in Beijing was low,with severe resistance of Shigella.Our findings suggested that clinicians should take multiple factors into account in their practices about epidemiological history,clinical symptom and testing results for diarrhea patients.

Systematic review on the characteristics of acute gastroenteritis outbreaks caused by sapovirus / 中华流行病学杂志

Objective To understand the epidemiological and etiological characteristics of outbreaks on acute gastroenteritis caused by sapovirus (SaⅤ) worldwide.Methods Literature about the outbreaks on acute gastroenteritis caused by SaⅤ were retrieved from the databases including WanFang,CNKI,PubMed and Web of Science after evaluation.Time,geography,setting and population distributions of outbreaks,transmission mode,SaⅤ genotype and clinical characteristics of the patients were analyzed.Results A total of 34 papers about SaⅤ were included,involving 146 outbreaks occurred between October 1976 and April 2016.In these papers,138 outbreaks were reported on the related months.All these outbreaks occurred in northern hemisphere.SaⅤ outbreaks occurred all year around,but mainly in cold season,the incidence was highest in December (25 outbreaks) and lowest in in August (2 outbreaks).Most outbreaks were reported by Japan,followed by Canada,the United States of America and the Netherlands.There were 141 outbreaks for which the occurring settings were reported,child-care settings were most commonly reported setting (48/141,34.04％),followed by long-term care facility (41/141,29.08％) and hospital (16/141,11.35％).Clinical symptoms of 1 704 cases in 31 outbreaks were reported,with the most common symptom was diarrhea (1 331/1 704,78.12％),followed by nausea (829/1 198,69.20％),abdominal pain (840/1 328,63.25％),vomiting (824/1 704,48.36％) and fever (529/1 531,34.53％).Genotypes of SaⅤ were determined for 119 outbreaks.GⅠ (51/119,42.86％) and GⅣ (45/119,37.82％) were predominant.The outbreaks of G Ⅳ SaⅤ increased suddenly in 2007,and the outbreaks of G Ⅰ SaⅤ mainly occurred in 2008 and during 2011-2013.Conclusions SaⅤ outbreaks were reported mainly by developed countries,with most outbreaks occurred in cold season,in child-care settings and long term care facility.G Ⅰ and GⅣ were the most common genotypes of SaⅤ.Prevention and control of SaⅤ outbreak in China seemed relatively weak,and it is necessary to conduct related training and to strengthen the SaⅤ outbreak surveillance in areas where service is in need.

Pathogenic surveillance and related factors on bacillary dysentery in Beijing, 2008-2017 / 中华流行病学杂志

Objective To analyze the pathogenic surveillance programs and related factors on bacillary dysentery in Beijing,2008-2017,to provide evidence for the practices of diagnosis,treatment and prevention of the disease.Methods Analysis was conducted on surveillance data of bacillary dysentery,collected from the surveillance areas of national bacillary dysentery in Beijing.Shigella positive rate of stool samples were used as the gold standard while detection rate of Shigella,diagnostic accordance rate and resistance were computed on data from the surveillance programs.Chi-square test was used to compare the rates and unconditional logistic regression was used to analyze the related factors of Shigella infection.Results Both the reported incidence rate on bacillary dysentery and detection rate of Shigella in diarrhea patients showed significantly decreasing trend,from 2008 to 2017.The accordance rate of bacillary dysentery was only 7.80％ (111/1 423).Shigella sonnei was the most frequently isolated strain (73.95％,159/215) followed by Shigella flexnery.Results from the multivariate logistic regression of Shigella positive rate revealed that among those patients who were routine test of stool positive vs.routine test of stool positive (OR=1.863,95％CI:1.402-2.475),onset from July to October vs.other months' time (OR=7.271,95％CI:4.514-11.709) temperature ≥38 ℃ vs.temperature ＜38 ℃ (OR=4.516,95％CI:3.369-6.053) and age from 6 to 59 years old vs.other ages (OR =1.617,95 ％ CI:1.085-2.410),presenting higher positive detection rates of Shigella from the stool tests.The resistant rates on ampicillin and nalidixic acid were 97.57％ (201/206) and 94.90％ (186/196),both higher than on other antibiotics.The resistant rates on ciprofloxacin (16.33％,32/196),ofloxacin (9.57％,11/115) and on amoxilin (15.05％,31/206) were relatively low.The resistant rate appeared higher on Shigellaflexnery than on Shigella sonnei.The proportion of strains with resistance on 3 more drugs,was 30.00％ (21/70).Conclusions The diagnostic accordance rate of bacillary dysentery in Beijing was low,with severe resistance of Shigella.Our findings suggested that clinicians should take multiple factors into account in their practices about epidemiological history,clinical symptom and testing results for diarrhea patients.

Systematic review on the characteristics of acute gastroenteritis outbreaks caused by sapovirus / 中华流行病学杂志

Objective To understand the epidemiological and etiological characteristics of outbreaks on acute gastroenteritis caused by sapovirus (SaⅤ) worldwide.Methods Literature about the outbreaks on acute gastroenteritis caused by SaⅤ were retrieved from the databases including WanFang,CNKI,PubMed and Web of Science after evaluation.Time,geography,setting and population distributions of outbreaks,transmission mode,SaⅤ genotype and clinical characteristics of the patients were analyzed.Results A total of 34 papers about SaⅤ were included,involving 146 outbreaks occurred between October 1976 and April 2016.In these papers,138 outbreaks were reported on the related months.All these outbreaks occurred in northern hemisphere.SaⅤ outbreaks occurred all year around,but mainly in cold season,the incidence was highest in December (25 outbreaks) and lowest in in August (2 outbreaks).Most outbreaks were reported by Japan,followed by Canada,the United States of America and the Netherlands.There were 141 outbreaks for which the occurring settings were reported,child-care settings were most commonly reported setting (48/141,34.04％),followed by long-term care facility (41/141,29.08％) and hospital (16/141,11.35％).Clinical symptoms of 1 704 cases in 31 outbreaks were reported,with the most common symptom was diarrhea (1 331/1 704,78.12％),followed by nausea (829/1 198,69.20％),abdominal pain (840/1 328,63.25％),vomiting (824/1 704,48.36％) and fever (529/1 531,34.53％).Genotypes of SaⅤ were determined for 119 outbreaks.GⅠ (51/119,42.86％) and GⅣ (45/119,37.82％) were predominant.The outbreaks of G Ⅳ SaⅤ increased suddenly in 2007,and the outbreaks of G Ⅰ SaⅤ mainly occurred in 2008 and during 2011-2013.Conclusions SaⅤ outbreaks were reported mainly by developed countries,with most outbreaks occurred in cold season,in child-care settings and long term care facility.G Ⅰ and GⅣ were the most common genotypes of SaⅤ.Prevention and control of SaⅤ outbreak in China seemed relatively weak,and it is necessary to conduct related training and to strengthen the SaⅤ outbreak surveillance in areas where service is in need.

Analysis on influencing factors for acute gastroenteritis outbreaks caused by norovirus in Beijing, 2014-2018 / 中华流行病学杂志

Objective@#To analyze the influencing factors of acute gastroenteritis outbreaks caused by norovirus in Beijing from 2014 to 2018.@*Methods@#Data of acute gastroenteritis events caused by norovirus in Beijing from April 2014 to March 2018 were collected. Unconditional logistic regression model was conducted to identify the risk factors of the outbreaks.@*Results@#A total of 765 acute gastroenteritis epidemics caused by norovirus were reported in Beijing, in which 85.88% (657/765) were cluster events and 14.12% (108/765) were outbreaks. Among the outbreaks, 70.37% (76/108) were reported in 2017; 84.26% (91/108) were reported in winter and spring; 88.89% (96/108) were reported in kindergartens, primary or secondary schools; 81.48% (88/108) were through person-to-person transmission; 93.52% (101/108) were caused by norovirus GⅡ infection. The risk of outbreaks in suburban and out suburb area were 1.84 times (95%CI: 1.13-3.02) and 3.78 times (95%CI: 1.62-8.82) as high as that in urban area, respectively. The risks of outbreaks in primary, secondary schools and other institutions were 6.26 times (95%CI: 3.53-11.10), 14.98 times (95%CI: 6.23-36.01) and 8.71 times (95%CI: 3.07-24.71) as high as that in kindergartens, respectively. The risk of outbreak in which patients having lower hospital visiting rate than the median rate of all events was 2.29 times than that in the context of having higher hospital visiting rate (95%CI:1.42-3.68). The risk of foodborne outbreak was 14.55 times as high as that transmitted through person-to-person (95%CI: 3.15-67.07).@*Conclusion@#Measures such as strengthening the prevention and control of norovirus outbreaks in suburbs, primary schools, secondary schools and other institutions, promoting patients to visit the hospital actively, improving the management of foodborne events and kitchen workers should be taken to reduce the incidence of acute gastroenteritis outbreaks caused by norovirus.