Objective: To investigate the seroprevalence and influencing factors of serum neutralizing antibodies among SARS-CoV-2 infected individuals, so as to provide the evidence for developing the health management and COVID-19 vaccination strategy among SARS-CoV-2 infected individuals. Methods: Recovered SARS-CoV-2 infected individuals from January 1st, 2020 to February 10th, 2021 in Zhejiang Province were recruited in March 2021. Participants' demographics, underlying diseases, date of definitive diagnosis and severity of clinical symptoms were collected using questionnaire surveys, and serum neutralizing antibody against SARS-CoV-2 was detected using a fluorescent immunoassay. In addition, factors affecting the seropositivity of neutralizing antibody against SARS-CoV-2 were identified using a multivariable logistic regression model. Results: A total of 559 SARS-CoV-2 infected individuals were enrolled, including 480 confirmed cases and 79 asymptomatic carriers, with an median (interquartile range) age of 47.00 (22.00) years, and all participants had never received COVID-19 vaccination. The median (interquartile range) duration from diagnosis to serum sampling was 387.00 (11.00) days, and the seroprevalence of neutralizing antibody against SARS-CoV-2 was 83.90%. The serum neutralizing antibody against SARS-CoV-2 was all positive 9 months after diagnosis, and the seroprevalence of neutralizing antibody against SARS-CoV-2 appeared no tendency towards a decline with time within 14 months after diagnosis (P>0.05). Multivariable logistic regression analysis showed that women were 1.892 times (95%CI: 1.169-3.064) more likely to produce serum neutralizing antibodies against SARS-CoV-2 than men, and mild, common and severe/critically ill SARS-CoV-2 infected cases were 2.438 (95%CI: 1.305-4.557), 4.481 (95%CI: 2.318-8.663), and 23.525 (95%CI: 2.990-185.068) times more likely to produce serum neutralizing antibodies against SARS-CoV-2 than asymptomatic carrier, respectively. Conclusions The seroprevalence of neutralizing antibody was 100.00% among SARS-CoV-2 infected individuals within 9 months after diagnosis. Individuals' gender and severity of clinical symptoms correlate with the seroprevalence of neutralizing antibody against SARS-CoV-2.

Objective: To investigate the epidemiological characteristics of influenza outbreaks in Zhejiang Province from 2013 to 2022, so as to provide insights into influenza prevention and control. Methods: Data pertaining to influenza outbreaks reported in Zhejiang Province from 2013 to 2022 were collected from National Influenza Surveillance System in China, including time, region, cases and pathogen types of influenza outbreaks. The temporal, spatial and pathogen distribution of influenza outbreaks were analyzed using a descriptive epidemiological method. Results: A total of 577 influenza outbreaks involving 448 698 individuals were reported in Zhejiang Province from 2013 to 2022, and the overall attack rate was 5.34% (23 974 cases), with no death reported. The lowest attack rate of influenza was 0.26%, and the highest was 80.00%, with a median attack rate of 10.89% (interquartile range, 24.26%). The outbreak had the shortest duration of 1.00 day, and the longest duration of 59.00 days, with a median duration of 9.00 (interquartile range, 11.00) days. There were 387 influenza outbreaks that occurred between November and January of the following year (67.07%), and the three highest numbers of outbreaks were reported in Hangzhou City (310 outbreaks), Wenzhou City (51 outbreaks) and Jinhua City (46 outbreaks). There were 395 outbreaks reported in urban regions (68.46%), 93 in counties and townships (16.12%) and 89 in rural regions (15.42%), and influenza outbreaks predominantly occurred in primary schools (487 outbreaks, 84.40%). In addition, the types of pathogens were alternately prevalent, with influenza B virus (241 outbreaks, 41.77%) and A/H3N2 virus (232 outbreaks, 40.21%) as predominant subtypes. Conclusions Influenza outbreaks mainly occurred in winter in Zhejiang Province from 2013 to 2022, and primary schools were main places of influenza outbreaks, while influenza B virus and A/H3N2 virus were predominant subtypes. It is necessary to reinforce the surveillance and report of influenza-like illness in schools and improve the coverage of influenza vaccination to prevent influenza outbreaks.

Objective : To analyze the epidemiological characteristics and pathogen spectrum of hand，foot mouth disease (HFMD) in Anhui province from 2015 to 2022，and to provide scientific evidence for prevention and control measures of HFMD． Methods : The surveillance data of hand，foot and mouth disease in Anhui province from 2015 to 2022 were analyzed by descriptive epidemiology. Real-time PCR was used to detect and classify HFMD samples. Results : A total of 650 590 HFMD cases were reported in Anhui province from 2015 to 2022，including 1 406 se- vere cases and 17 deaths．The annual reported incidence was 131. 45 /100 000．The epidemic features of“low incidence in odd years and high incidence in even years”were presented from 2015 to 2019．The incidence showed a continuous decline from 2020 to 2022．The monthly distribution showed the characteristics of bimodal epidemic，and the main peak was not obvious in 2020．Hefei，Fuyang，Bozhou，Chuzhou and Suzhou ranked the top five cities in terms of cumulative incidence．The age of onset was mainly distributed in children aged 5 years and below，accounting for 89. 26% of the total cases．The male to female ratio was 1. 48 ∶ 1．A total of 28 657 laboratory-confirmed cases had been reported from 2015 to 2022．EV71 cases accounted for 10. 57% ，Cox A16 cases accounted for 24. 90% ，and other enterovirus cases accounted for 64. 53%．The dominant pathogens showed dynamic changes in different years．Since 2018，the proportion of EV71 decreased significantly，and the proportion of other enteroviruses gradually increased to become the dominant pathogens．Among other enteroviruses，Cox A6 strain was dominant (80. 48% ) ． Conclusion This study suggests that the prevention and control of HFMD in Anhui province should be paid more attention from April to July and from October to December．The focus areas are the cities in northern Anhui and Hefei where the floating population is large．The focus of prevention and control is on children aged 5 years and below．Other enteroviruses have become the dominant pathogens of hand-foot-mouth disease in Anhui province，Cox A6 strain is dominant.

Objective:To investigate the clinical features of patients with anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis misdiagnosed as mental disorder, improve the early diagnosis rate and reduce misdiagnosis.Methods:The clinical data of patients with anti-NMDA receptor encephalitis diagnosed at the First Affiliated Hospital of Zhengzhou University from 2012 to 2018 were collected. Patients misdiagnosed as mental disorders were screened out. Their psychiatric symptom characteristics, disease course characteristics, imaging and laboratory findings, treatment and prognosis were retrospectively analyzed.Results:A total of 121 cases of anti-NMDA receptor encephalitis were collected, and 43 cases of mental disorders were screened out. Sixteen of the 43 patients (37.2%) had prodromal symptoms, and all the patients had psychiatric behavioral abnormalities (100%), including 32 cases (74.4%) of seizures, 13 cases (30.2%) of decreased level of consciousness, 21 cases (48.8%) of involuntary movements, 15 cases (34.9%) of decreased memory, 8 cases (18.6%) of speech dysfunction, and 8 cases (18.6%) of other neurological symptoms (central hyperventilation, autonomic dysfunction). Memory loss was observed in 15 cases (34.9%), speech dysfunction in 8 cases (18.6%), other neurological symptoms (central hypoventilation, autonomic dysfunction) in 8 cases (18.6%), and various symptoms may appear simultaneously or successively in the same patient. Thirty-eight cases had complete resolution of symptoms or only minor physical impairment, and 5 cases had recurrent admissions with mental abnormalities and seizures. The recurrence rate accounted for 11.6% (5/43).Conclusions:The clinical manifestations of anti-NMDA receptor encephalitis are complex and varied. Most of them have mental behavior abnormalities as the first symptom, which is easily misdiagnosed as mental disorder and delayed treatment will lead to prolonged disease course and poor prognosis.

Objective:To investigate the epidemiological characteristics for family clusters of COVID-19 in Zhejiang Province.Methods:The data including cases information of asymptomatic infected cases of family clusters of COVID-19 in Zhejiang Province were collected from Public Health Emergencies Reporting System of China Center for Disease Control and Prevention. Calculate the case number of subsequent cases, index cases, asymptomatic infected cases, exposure cases, and then, compute family secondary attack rate (SIR) and serial interval.Results:A total of 389 cases comprised 149 family index cases and 240 subsequent cases. The clinical symptoms between family index cases and subsequent cases (exclude asymptomatic infected cases ) were similar, fever was the most common symptoms in the two groups 115 (77.18%) and 110（48.67%）respectively, the cases with diarrhea symptoms accounted for the least proportion, which were 7 (4.70%) and 6 (2.65%) respectively. The serial interval between the family index cases and the subsequent cases [ M ( P25, P75)] was 4.00 (2.00, 6.00) days. Family secondary attack rate for subsequent cases was 34.43%, subsequent cases aged between 14 and 60 have the highest SIR (43.42%) compared with other two age groups, the difference was statistically ( P<0.001); the family SIR of the spouses of the family index cases is 68.57%, and are higher than that of parents (29.03%), children (25.00%) and other family members (24.21%), the difference was also statistically ( P<0.001). Conclusion:2019 novel coronavirus has shorter serial interval and higher family SIR, the SIR of spouses is higher than other family members.

Objective:To investigate the epidemiological characteristics for family clusters of COVID-19 in Zhejiang Province.Methods:The data including cases information of asymptomatic infected cases of family clusters of COVID-19 in Zhejiang Province were collected from Public Health Emergencies Reporting System of China Center for Disease Control and Prevention. Calculate the case number of subsequent cases, index cases, asymptomatic infected cases, exposure cases, and then, compute family secondary attack rate (SIR) and serial interval.Results:A total of 389 cases comprised 149 family index cases and 240 subsequent cases. The clinical symptoms between family index cases and subsequent cases (exclude asymptomatic infected cases ) were similar, fever was the most common symptoms in the two groups 115 (77.18%) and 110（48.67%）respectively, the cases with diarrhea symptoms accounted for the least proportion, which were 7 (4.70%) and 6 (2.65%) respectively. The serial interval between the family index cases and the subsequent cases [ M ( P25, P75)] was 4.00 (2.00, 6.00) days. Family secondary attack rate for subsequent cases was 34.43%, subsequent cases aged between 14 and 60 have the highest SIR (43.42%) compared with other two age groups, the difference was statistically ( P<0.001); the family SIR of the spouses of the family index cases is 68.57%, and are higher than that of parents (29.03%), children (25.00%) and other family members (24.21%), the difference was also statistically ( P<0.001). Conclusion:2019 novel coronavirus has shorter serial interval and higher family SIR, the SIR of spouses is higher than other family members.

Objective: Victims with shock-able initial arrest rhythms (ventricular fibrillation or pulse-less ventricular tachycardia, VF/VT) have much better outcomes from out-of-hospital cardiac arrest (OHCA) than those with non-shock-able initial rhythms (pulse-less electrical activities, PEA or asystole). Prompt defibrillation is believed pivotal to terminate lethal shock-able arrest rhythms. In this study, we were to identify those pre-hospital epidemiological factors which were associated with likelihood of shock-able rhythms first recorded when out-of-hospital cardiac arrest occurred. Methods: A multicenter, secondary, retrospective and observational analysis was performed on all adult non-traumatic OHCA in the Resuscitation Outcome Consortium (ROC) PRIMED study from June 2007 through November 2009. Of a total of 17 177 OHCA cases in PRIMED study, 13 421 of them were enrolled in this study when those OHCA patients with DNR order, or initial rhythms unknown, or arrest caused by obvious cause were excluded. We reported their demographics and episode characteristics for all enrolled cases. Multivariable logistic regression was employed to identify factors which were associated with likelihood of VF/VT recorded as shock-able initial rhythms. Results: Among 13 421 adult non-traumatic OHCA cases with initial rhythms recorded, 3 527 (26.3%) of them had shock-able rhythms, while 9 894 (73.7%) patients were in non-shock-able rhythms. Of the OHCA with shock-able arrest rhythms, 1 850(52.5%) obtained return of spontaneous circulation (ROSC) in the field, while 912 (25.9%) survived to hospital discharge. On the other hand, 2489(25.2%) of the OHCA with non-shock-able arrest rhythms obtained ROSC in the field, while 325 (3.3%) of them survived to hospital discharge. Multivariable regression analysis revealed those factors which indicated likelihood of shock-able rhythms recorded were: age(OR: 0.991,95%CI 0.988-0.993), male gender (OR1.887,95%CI1.718-2.073), pre-hospital Emergency Medical System(EMS) response time(OR0.950,95%CI 0.931-0.970), cardiac arrest witnessed by EMS providers(OR1.709,95%CI 1.423-2.054) or bystander(OR3.199,95%CI 2.921-3.504) and those with bystanders CPR (OR1.357,95%CI 1.239-1.487),public place of cardiac arrest (OR2.705,95%CI 2.437-3.003). Conclusions Some demographics and pre-hospital characteristics were proved associated with likelihood of shock-able arrest rhythms first recorded in OHCA victims, which might help develop corresponding strategies to deliver prompt shock on initially shock-able patients and improve their outcomes.

Objective: To observe the change levels of nuclear factor-kappa B (NF-κB) p65 protein in cytoplasm and nuclear, phosphorylation of inhibitor of kappa B (p-IκB) protein and cytochrome C (Cyt-c) , cleaved cysteinyl aspartate specific proteinase-3 (Cleaved caspase-3) , B-cell lymphoma/leukemia-2 (Bcl-2) in cytoplasm in the process of N, N-dimethylformamide (DMF) -induced apoptosis in H9c2 cardiomyocytes, and explore the tentative mechanism of apoptosis. Methods: H9c2 cardiomyocytes were exposed to 200 mmol/L DMF. Western blotting was used to detect the protein expression levels of p65 in cytoplasm and nuclear, p-IκB after exposure for 0, 2, 4, 6, 8, 12 h, and the protein expression levels of Cyt-c, Cleaved caspase-3, Bcl-2 in cytoplasm after exposure for 0, 2, 4, 8, 12, 24 h. Immunofluorescencecytochemistry (IFC) was used to observe the location of Cyt-c after 200 mmol/L DMF exposure for different times. Results: The levels of p65 in cytoplasm and nuclear and p-IκB among groups were statistically significant (F were 7.79, 33.11, 90.25, respectively, all P<0.01) . Compared with the control group, the levels of p65 in cytoplasm of 2, 4, 6 h group were significantly decreased (all P<0.01) ; the levels of p65 in nuclear of 2, 4, 6, 8 h were significantly increased (all P<0.01) ; the levels of p-IκB of 2, 4, 6 h group were significantly increased (all P<0.01) . The levels of Cyt-c, Cleaved caspase-3 and Bcl-2 among groups were statistically significant (F were 51.42, 503.68, 73.37, respectively, all P<0.01) . Compared with the control group, the levels of Cyt-c of 8, 12 h group were significantly increased (both P<0.01) ; the levels of Cleaved caspase-3 of 2, 4, 8, 12, 24 h were significantly increased (all P<0.01) ; the levels of Bcl-2 of 2, 4, 8, 12, 24 h group were significantly decreased (all P<0.01) . IFC showed that Cyt-c was released from the mitochondria to the cytoplasm gradually as the extension of the exposure time. Conclusion NF-κB signaling pathway and mitochondrial pathway are involved in the mechanism of DMF-induced apoptosis in H9c2 cardiomyocytes.

OBJECTIVE: To explore the effect of N,N-dimethylformamide( DMF)-induced inflammatory injury in H9c2 cardiomyocytes and its mechanism. METHODS: H9c2 cardiomyocytes were cultured in vitro and randomly divided into 4different groups: control group,50 mmol / L-group,100 mmol / L-group,200 mmol / L-group. These 4 groups of cells were treated with different DMF concentrations( 0,50,100,200 mmol / L) for 12 hours. The cells were also divided into 6groups and treated with 200 mmol / L DMF at different time points( 0,2,4,6,8,12 h) : control group,2 h-group,4 hgroup,6 h-group,8 h-group and 12 h-group. The level of lactate dehydrogenase( LDH) was detected by colorimetry. The levels of creatine kinase( CK) and isoenzyme of creatine kinase( CK-MB) were detected by ultraviolet spectrometry. The levels of tumor necrosis factor-α( TNF-α),interleukin( IL)-1β,IL-6,and IL-8 were detected by enzyme linked immunosorbent assay. The level of reactive oxygen species( ROS) was detected by fluorescence probe. The location of nuclear factor-kappa B( NF-κB) p65 protein was detected by immunofluorescence cytochemistry( IFC) staining. RESULTS: The levels of LDH,CK and CK-MB in the 50 mmol / L-group,100 mmol / L-group and 200 mmol / L-group were higher than that of the control group( P < 0. 05) and showed a significant dose-effect( P < 0. 05). The levels of LDH,CK and CK-MB in the 6 h-group,8 h-group and 12 h-group were higher than that of the control group( P < 0. 01) and showed a significant time-effect( P < 0. 01). The levels of TNF-α,IL-1β,IL-6 and IL-8 of the 200 mmol / L-group were higher than the control group( P < 0. 05). Compared with the control group,the levels of TNF-α of the 4 h-group,12 h-group were higher( P < 0. 05),the levels of IL-1β of the 2 h-group,4 h-group,6 h-group,8 h-group and 12 h-group were higher( P < 0. 05),the levels of IL-6 of the 2 h-group and 4 h-group were higher( P < 0. 05),the level of IL-8 of the 2 h-group was higher( P < 0. 05). In addition,the levels of TNF-α,IL-1β and IL-6 reached a peak at 4 h-group and the level of IL-8 reached a peak at 2 h-group. The ROS levels of the 2 h-group,4 h-group and 6 h-group were higher than the control group( P < 0. 01),and the level of ROS reached a peak at 2 h-group. Furthermore,IFC staining showed that the fluorescence intensity of NF-κB p65 protein in nucleus of the 2h-group and 4 h-group increased after treatment with DMF,comparing with the control group. CONCLUSION: DMF leads to inflammatory injury in H9c2 cardiomyocytes. ROS and NF-κB might be involved in the process.

Objective To explore the expressions of Bcl-2 and Bax proteins in the neurons of spinal cord after tibial nerve and common peroneal nerve injuries in rats.Methods A total of 90 male SD rats were randomly divided into three groups, the group A was as control group, group B as suture of tibial nerve cut group, and group C as suture of the common peroneal nerve cut group.The L4-6 segment spinal cord of the rats were removed for HE staining and immumohistochemical staining on 3, 7, 14, 28 days after the operation.The number of motor neurons in the spinal anterior horn were calculated.The expressions differences of Bcl-2 and Bax proteins were detected by immuno-histochemistry, and values of Bcl-2/Bax were calculated.Results The number of motor neurons in the anterior horn of spinal cord in group B were less than that in group C on 1, 3, 7, 14, 28 days after the operation (P< 0.01).The expression of Bcl-2 protein in group B and group C showed an upward and then declining trend.It decreased to the lowest on the postoperative 3 d in group B and 7 d in group C, respectively.The expressions of Bax protein in group B and C showed an upward and then declining trend, and it increased to the highest on the postoperative 3 d in groups B and C.The values of Bcl-2/Bax in groups B and C were showed an decreased and then increased trend and it was lower in group B than group C on the postoperative 3, 7, 14, 28 d(P< 0.01).Conclusion Injuries of tibial nerve and common peroneal nerve of the rats would lead the apoptosis of motor neurons in the spinal cord, but compared with the injury of common peroneal nerve, tibial nerve injury would lead less apoptosis of motor neurons.