Objective: To monitor and analyze the epidemiological characteristics of influenza in schools and understand the disease burden of students, and to provide a scientific reference for instructing the prevention of influenza in schools. Methods: A school influenza surveillance sentinel to conduct influenza like case (ILI) surveillance and outbreak surveillance. Through network, we understood the burden of flu disease among students. Descriptive epidemiology was used to analyze influenza like case surveillance and questionnaire survey data. Results: Surveillance confirmed that from the 42th week of 2019 to the 1st week of 2020, the cumulative reported ILI of 3 school influenza surveillance sites in Jinan accounted for 7.91% (ILI%) of the total number of surveillance personnel during the same period, with the highest ILI% (24.19%) of kindergarten children, ILI% gradually decreased with the increase of grade, and teachers were the lowest. The reporting of ILI was concentrated in the 49th to 52nd week of 2019, during which the reported influenza like cases accounted for 84.81% of the total number of ILI reported during the surveillance period. Two influenza outbreaks were monitored. The pathogens were H3N2 and B (Victoria). The epidemics mainly occurred in the lower grades of elementary school. A survey of 2 297 students found that 577 people had fever and respiratory symptoms since October 2019. Among them, 85.26% of them went to the hospital, 32.75% of those who used anti influenza drugs such as oseltamivir, and 64.81% of those who used antibiotics. 42.63% received infusion therapy, 3.99% were hospitalized, and the average cost of inpatients was 6 686 yuan. The sick students were absent from school for an average of 3.77 days, and the parents of the sick children missed work for an average of 4.26 days. Conclusion Surveillance of influenza like cases in schools is an important way to proactively discover influenza epidemic trends and outbreaks, and to accurately grasp the characteristics of influenza epidemics in schools. The key populations affected by influenza are kindergarten children and lower grades of primary school students. Suffering from influenza has caused a heavy disease burden on students and children in kindergartens, and is also an important factor that causes student absenteeism and parents to miss work.

Objective To analyze the epidemiological characteristics and spatiotemporal clustering of scarlet fever in Jinan, from 2014-2019, and to provide a basis for scarlet fever prevention and control. Methods The case data of scarlet fever in Jinan during 2013-2019 were extracted from the Chinese National Notifiable Infectious Disease Reporting System. Descriptive epidemiology and spatiotemporal rearrangement scanning methods were used to analyze the epidemiological characteristics and spatiotemporal distribution of scarlet fever. The RR values of scarlet fever in different towns (streets) were calculated, and the contour map of RR value was drawn. Results A total of 9 715 cases of scarlet fever were reported in Jinan from 2014 to 2019. During this period, the number of cases and the incidence rate showed a gradual increase, with two seasonal peaks in the winter and spring each year. Spatiotemporal clustering analysis detected a total of eight spatiotemporal aggregation areas, and the strongest one was in Licheng and Lixia Districts, from March 2017 to December 2019 (RR=3.45, LLR=577.88, P<0.001). The relative risk maps in each year from 2014 to 2019 were similar, and the areas with the highest risk were located in the central area of Jinan. Conclusion From 2014 to 2019, scarlet fever is highly prevalent in the central area of Jinan, with obvious spatial and temporal clustering. There are clustering areas in the central, southwest and eastern areas of Jinan, and there was a tendency for the disease to spread to Zhangqiu in the east and Pingyin in the southwest.

The outbreak of coronavirus disease (COVID-19) caused by SARS-CoV-2 virus continually lead to worldwide human infections and deaths. Currently, there is no specific viral protein-targeted therapeutics. Viral nucleocapsid protein is a potential antiviral drug target, serving multiple critical functions during the viral life cycle. However, the structural information of SARS-CoV-2 nucleocapsid protein remains unclear. Herein, we have determined the 2.7 Å crystal structure of the N-terminal RNA binding domain of SARS-CoV-2 nucleocapsid protein. Although the overall structure is similar as other reported coronavirus nucleocapsid protein N-terminal domain, the surface electrostatic potential characteristics between them are distinct. Further comparison with mild virus type HCoV-OC43 equivalent domain demonstrates a unique potential RNA binding pocket alongside the -sheet core. Complemented by binding studies, our data provide several atomic resolution features of SARS-CoV-2 nucleocapsid protein N-terminal domain, guiding the design of novel antiviral agents specific targeting to SARS-CoV-2.

Objective To investigate the feasibility of using optimized protocol of iodine contrast agent with fixed injection time in triple-rule-out CT examination of acute chest pain patients. Methods A prospective study was conducted. The patients who underwent triple-rule-out CT examination of acute chest pain at the Second Hospital of Shanxi Medical University from September 2017 to June 2018 were enrolled. According to the patient's body mass index (BMI), they were divided into BMI ≤ 23 kg/m2 group and BMI > 23 kg/m2 group. The patients in each group were subdivided into two subgroups according to the random number table, and they were given two iodine contrast injection protocols with fixed injection time (14 s). Protocol 1 was performed with 55 mL of total iodinated contrast media: iodinated contrast media was first injected at 5.0 mL/s for 8 s, followed by the same contrast media injection at 2.5 mL/s for 6 s, finally followed by injection of 40 mL of saline at a rate of 2.5 mL/s. Protocol 2 with 60 mL of total iodinated contrast media: iodinated contrast media was first injected at 5.0 mL/s for 10 s, followed by the same contrast media injection at 2.5 mL/s for 4 s, finally followed by injection of 40 mL of saline at a rate of 2.5 mL/s. The primary and objective evaluation was conducted on the image quality of the patients' blood vessels in different segments. The primary score, CT value and contrast-to-noise ratio (CNR) of the pulmonary artery, coronary artery, aorta and total effective radiation dose for the examination were recorded. Results A total of 92 patients were enrolled in the analysis. There were 44 patients in BMI≤ 23 kg/m2 group, in which 22 patients received in protocol 1 and protocol 2, 48 patients in BMI > 23 kg/m2 group, in which 24 patients in protocol 1 and protocol 2, respectively. There was no significant difference in the effective radiation dose between the two subgroups receiving different injection protocols in different BMI groups (mSv: 6.7±1.1 vs. 6.5±0.8 between protocol 1 and protocol 2 in BMI ≤ 23 kg/m2 group; 7.8±1.0 vs. 8.0±1.1 between protocol 1 and protocol 2 in BMI > 23 kg/m2 group, both P > 0.05). In BMI ≤ 23 kg/m2 group, the CT value, CNR and primary scores of pulmonary artery images in patients receiving protocol 2 were significantly higher than those receiving protocol 1 [CT value (HU): 584±110 vs. 472±86 for main pulmonary artery, 561±93 vs. 467±78 for left pulmonary artery, 555±91 vs. 472±83 for right pulmonary artery; CNR: 24.2±7.5 vs. 18.7±4.6 for main pulmonary artery, 23.2±6.8 vs. 18.6±4.8 for left pulmonary artery, 22.9±6.7 vs. 18.8±4.7 for right pulmonary artery; primary score:4.0 (4.0, 4.0) vs. 3.5 (3.0, 4.0), all P < 0.05]; and there was no statistically significant difference in the primary or objective evaluation of coronary artery or aortic image quality between the two protocols. In BMI > 23 kg/m2 group, the CT value, CNR and primary scores of coronary artery and aortic images in patients receiving protocol 2 were significantly higher than those receiving protocol 1 [CT value (HU): 369±63 vs. 315±61 for proximal right coronary artery (RCA), 388±63 vs. 323±63 for proximal left coronary artery (LCA), 328±83 vs. 272±51 for ascending aorta, 348±82 vs. 272±49 for aortic arch; CNR: 15.0±4.6 vs. 12.3±4.7 for proximal RCA, 15.7±3.8 vs. 12.8±5.2 for proximal LCA, 13.2±5.3 vs. 10.4±4.1 for ascending aorta, 14.1±5.3 vs. 10.4±3.9 for aortic arch; primary score: 4.0 (3.0, 4.0) vs. 3.0 (3.0, 4.0) for coronary, 4.0 (3.0, 4.0) vs. 3.0 (2.0, 4.0) for aorta; all P < 0.05]; and there was no statistically significant difference in the primary or objective evaluation of pulmonary artery image quality between the two protocols. Conclusions The effective radiation dose of triple-rule-out CT examination of acute chest pain is relatively low. The low-dose iodine contrast agent application program with fixed injection time can meet the needs of clinical diagnosis of triple-rule-out CT examination of acute chest pain patients. For patients with BMI ≤ 23 kg/m2, both protocols 1 and 2 can obtain excellent image quality; in order to avoid the influence of superior vena cava artifacts, protocol 1 is recommended. For patients with BMI > 23 kg/m2, application protocol 2 can obtain stable, excellent image quality that is more suitable for clinical applications.

Objective To investigate the iodine nutritional status of pregnant women in Jinan City,which may provide a basis for scientific supplementation of iodine.Methods Ten counties (districts) in Jinan City were divided into five areas as east,west,south,north and middle in 2018.At least one township (street) was selected from each area,and 20 pregnant women were selected from each township (street).Personal information was collected through standardized questionnaires,and household salt samples and urine samples of pregnant women were collected.Salt iodine and urinary iodine were detected by the "General Test Method in Salt IndustryDetermination of Iodine" (GB/T 13025.7-2012) and "Method for Determination of Iodine in Urine by As3+-Ce4+ Catalytic Spectrophotometry" (WS/T 107-2006),respectively.Results A total of 1 169 pregnant women's household salt samples were collected,the median of salt iodine was 22.6 mg/kg.The coverage rate of iodized salt was 90.5％ (1 058/1 169),the qualified rate of iodized salt was 75.8％ (802/1 058),and the consumption rate of qualified iodized salt was 68.6％ (802/1 169).A total of 1 169 urine samples of pregnant women were tested,the median of urinary iodine was 141.9 μg/L,indicating the urinary iodine of pregnant women was insufficient (＜ 150 μg/L).Conclusions The iodine nutrition of pregnant women is slightly inadequate in Jinan City.It is necessary to strengthen the measures in prevention and control of iodine deficiency,and promote the health education measures in pregnant women to improve their iodine deficiency status.

Objective To investigate the antimicrobial resistance profile of the clinical isolates collected from selected hospitals across China. Methods Twenty-nine general hospitals and five children's hospitals were involved in this program. Antimicrobial susceptibility testing was carried out according to a unified protocol using Kirby-Bauer method or automated systems. Results were interpreted according to CLSI 2017 breakpoints. Results A total of 190 610 clinical isolates were collected from January to December 2017, of which gram negative organisms accounted for 70.8％ (134 951/190 610) and gram positive cocci 29.2％ (55 649/190 610). The prevalence of methicillin-resistant strains was 35.3％ in S. aureus (MRSA) and 80.3％ in coagulase negative Staphylococcus (MRCNS) on average. MR strains showed much higher resistance rates to most of the other antimicrobial agents than MS strains. However, 91.6％ of MRSA strains were still susceptible to trimethoprim-sulfamethoxazole, while 86.2％ of MRCNS strains were susceptible to rifampin. No staphylococcal strains were found resistant to vancomycin. E. faecalis strains showed much lower resistance rates to most of the drugs tested (except chloramphenicol) than E. faecium. Vancomycin-resistant Enterococcus (VRE) was identified in both E. faecalis and E. faecium. The identified VRE strains were mainly vanA, vanB or vanM type based on phenotype or genotype. The proportion of PSSP or PRSP strains in the non-meningitis S.pneumoniae strains isolated from children decreased but the proportion of PISP strains increased when compared to the data of 2016. Enterobacteriaceae strains were still highly susceptible to carbapenems. Overall, less than 10％ of these strains (excluding Klebsiella spp.) were resistant to carbapenems. The prevalence of imipenem-resistant K. pneumoniae increased from 3.0％ in 2005 to 20.9％ in 2017, and meropenem-resistant K. pneumoniae increased from 2.9％ in 2005 to 24.0％ in 2017, more than 8-fold increase. About 66.7％ and 69.3％ of Acinetobacter (A. baumannii accounts for 91.5％) strains were resistant to imipenem and meropenem, respectively. Compared with the data of year 2016, P. aeruginosa strains showed decreasing resistance rate to carbapenems. Conclusions Bacterial resistance is still on the rise. It is necessary to strengthen hospital infection control and stewardship of antimicrobial agents. The communication between laboratorians and clinicians should be further improved in addition to surveillance of bacterial resistance.

Objective To analyze the resistance proifle of bacterial strains isolated from geriatric patients in 17 hospitals across China from 2005 to 2014.Methods A total of 17 representative general hospitals were involved in this program. Bacterial susceptibility testing was carried out by means of a uniifed protocol using Kirby-Bauer method and MIC determination. The results were analyzed according to CLSI 2014 breakpoints.Results The proportion of the strains isolated from geriatric patients among all the clinical isolates increased with time from 30.0% in 2005 to 32.7% in 2014. A total of 159 888 clinical isolates were collected from geriatric patient during the period from 2005 to 2014, about 33.1% of the whole patient population. Gram negative organisms and gram positive cocci accounted for 77.1% (123 229/159 888) and 22.9% (36 659/159 888), respectively. Majority (92.8%, 148 376/159 888) of the isolates were from inpatients and more than half (55.2%, 88 201/159 888) of the isolates were from sputum or other respiratory tract specimens. Methicillin-resistant strains inS. aureus (MRSA) and coagulase negativeStaphylococcus (MRCNS) accounted for an average of 67.1% and 75.9%, respectively. The resistance rates of methicillin-resistant strains to β-lactams and other antimicrobial agents were much higher than those of methicillin-susceptible strains. No staphylococcal strains were found resistant to vancomycin, teicoplanin or linezolid. Some strains ofE. faecalis (0.4%) andE. faecium (4.6%) were resistant to vancomycin, which was higher than average national level (0.3%, 3.2%). Vancomycin-resistant strains ofE. faecalisandE. faecium were mainly VanA type and VanB type based on their phenotype. The prevalence of penicillin-susceptibleS. pneumoniae strains was 78.2%, slightly lower than the 95.0% in Chinese adults in year 2014. The prevalence of ESBLs-producing strains was 67.5% inE. coli, 40.4% inKlebsiella (K. pneumoniae andK. oxytoca) and 34.3% inProteus mirabilis isolates on average. The strains ofEnterobacteriaceae were still highly susceptible to carbapenems (<10% resistant), followed by amikacin and the beta-lactam and beta-lactamase inhibitor combinations. Overall, 35.9% and 33.0% of theP. aeruginosa strains were resistant to imipenem and meropenem. More than 50% of theA. baumannii strains were resistant to imipenem and meropenem. The prevalence of extensively drug-resistant (XDR)P. aeruginosa (4.0%-1.8%) was higher than the average national level (2.1%-1.6%). The prevalence of XDR A. baumannii (19.2%-15.5%) and XDREnterobacteriaceae (0.1%-1.0%) was lower than the average national level (21.4%-19.7% and 0.3%-3.2%).Conclusions The proportion of clinical isolates from geriatric patients is different from average national level at the same period. The isolates from geriatric patients are more likely from inpatients, respiratory tract specimens and more likely non-fermentative gram-negative bacilli compared to average national level. The proportion of fastidious bacteria andEnterobacteriaceae species is generally lower than average national level. MRSA, VRE, ESBLs-producing strains and XDRP. aeruginosa are more prevalent in geriatric patients than in general Chinese patient population. This study suggests that surveillance of antimicrobial resistance for the clinical isolates from geriatric patients is very important for rational antimicrobial therapy.

Objective To investigate the distribution and changing resistance proifle ofSalmonella isolates in hospitals across China during the period from January 2005 to December 2014.Methods Seventeen general hospitals and two children’s hospitals were involved in this program. Antimicrobial susceptibility testing was carried out by means of a unified protocol using Kirby-Bauer method or MIC determination. The results were analyzed according to CLSI 2014 breakpoints.Results The proportion ofSalmonella isolates increased with time from 0.2% in 2005 to 0.7% in 2014. A total of 3 478Salmonella strains were collected from 19 hospitals. The proportion ofSalmonella typhimurium andSalmonella enteritidis was 27.4% and 24.4%, respectively. During the 10-year period, theSalmonella strains showed highest resistance rate to ampicillin (33.3%-64.8%), but low resistance to cefoperazone-sulbactam (0-5.3%) and ciprofloxacin (2.4%-14.3%).S. typhimurium showed higher resistance rate thanS. typhi,S. paratyphi andS. enteritidis. About 76.8% and 50.5% ofS. typhimurium were resistant to ampicillin and trimethoprim-sulfamethoxazole. The average prevalence of multi-drug resistantSalmonellawas 3.9% in the ten-year period, the highest (7.5%) was in 2005, the lowest (1.5%) in 2013.Conclusions During the period from 2004 to 2015, majority of theSalmonella isolates in hospitals across China wasS. typhimurium andS. enteritidis. Ampicillin and trimethoprim-sulfamethoxazole are no longer appropriate for empirical treatment ofS. typhimurium infection due to high resistance rate.Salmonella isolates are relatively more susceptible to third-generation cephalosporins and quinolones. Ongoing monitoring is necessary to identify multi-drug resistant strains ofSalmonella.

Objective To understand the changing resistance proifle ofProteus,Serratia,Citrobacter,Morganella andProvidencia in hospitals across China according to the data from CHINET Antimicrobial Resistance Surveillance Program 2005-2014.Methods Antimicrobial susceptibility was tested by using Kirby-Bauer method or automatic minimum inhibitory concentration determination according to a uniifed protocol.Results A total of 21 663 clinical isolates were collected from January 2005 to December 2014. The proportion ofProteus andSerratia isolates increased with time from 1.41% in 2005 to 2.09% in 2014, and from 0.99% in 2005 to 1.28% in 2014 among all the isolates. No change was found for the proportion ofCitrobacter,Morganella, orProvidencia. Less than 10% of theProteus isolates were resistant to cefoperazone-sulbactam, piperacillin-tazobactam, ceftazidime, cefoxitin, amikacin and tigecycline. Less than 10% of theSerratia isolates were resistant to cefoperazone-sulbactam, piperacillin-tazobactam, amikacin and tigecycline. Less than 20% of theCitrobacter isolates were resistant to cefoperazone-sulbactam, piperacillin-tazobactam, cefepime, amikacin and tigecycline. Less than 10% of theMorganella isolates were resistant to cefoperazone-sulbactam, piperacillin-tazobactam, cefepime, amikacin and tigecycline. Less than 20% of theProvidencia isolates were resistant to cefoperazone-sulbactam, piperacillin-tazobactam, cefepime, cefoxitin and tigecycline.Conclusions The antibiotic resistance ofProteus,Serratia, Citrobacter,Morganella andProvidencia isolates in hospitals across China is growing during the period from 2005 to 2014. Strengthening infection control and rational antibiotic use are effective to slow the growth of drug resistance.

Objective To investigate the distribution and antibiotic resistance proifle of clinicalEnterobacter isolates using the data from CHINET during the period from 2005 through 2014.Methods A total of 20 558 clinical strains ofEnterobacter spp. were collected from 2005 to 2014 in CHINET Antimicrobial Resistance Surveillance Program. Antimicrobial susceptibility testing was performed with Kirby-Bauer or minimum inhibitory concentration method. The results were analyzed according to CLSI 2014 breakpoints.ResultsEnterobacter cloacae andEnterobacter aerogenes accounted for 71.1% (14 617/20558) and 20.1% (4 129/20 558) of all theEnterobacterisolates, respectively. The proportion ofEnterobacter spp. increased with time from 3.5% in 2005 to 4.3% in 2014. The main source of the isolates was respiratory tract, accounting for 55.2% (11 358/20 558). More than 90% of theEnterobacterisolates were resistant to cefazolin and cefoxitin, but less than 30% of the strains were resistant to cefepime, piperacillin-tazobactam, cefoperazone-sulbactam, amikacin, gentamicin, ciprolfoxacin, meropenem, imipenem and ertapenem. TheEnterobacterisolates showed a trend of declining resistance to most antibiotics except ertapenem and meropenem. The resistance proifle ofEnterobacterisolates varied with departments where they were isolated. The strains from ICU and Department of Surgery were relatively more resistant to antibiotics. The prevalence of multi-drug resistant (MDR) strains was decreasing, but the prevalence of carbapenem-resistantEnterobacter (CRE, resistant to any of imipenem, meropenem or ertapenem) was increasing. The MDR and CRE strains were primarily isolated from ICU and Department of Surgery. At least 30% of the MDREnterobacter strains were resistant to any of the antimicrobial agents tested except meropenem, imipenem and ertapenem and at least 35% of the CRE strains were resistant to any of the antimicrobial agents tested except amikacin and ciprolfoxacin.Conclusions TheEnterobacter isolates in CHINET Antimicrobial Resistance Surveillance Program showed decreasing resistance to most of the antimicrobial agents tested since 2011, but the prevalence of CRE strains increased progressively. Effective measures should be carried out to prevent the spread of CRE strains in hospitals.