Objective:To analyze the molecular epidemiological characteristics of norovirus (NoV) outbreaks in Qingdao.Methods:Anus swab specimens were collected during NoV outbreaks from 2016 to 2020 and detected by real-time RT-PCR. Full length of RNA-dependent RNA polymerase (RdRp) and VP1 gene were amplified by RT-PCR for sequencing, evolutionary analysis, and homology modeling.Results:A total of 65 NoV outbreaks were reported, with 59 outbreaks occurring in kindergartens and primary/secondary schools, showing a double peak epidemic pattern, with peaks occurring from March to May and from October to December. A GⅡ.P16 outbreak in Qingdao first appeared in March 2017 and became the predominant strains from 2017 to 2020(67.9%, 38/56), including two genotypes: GⅡ.2[P16] (97.4%, 37/38) and GⅡ.4 Sydney[P16] (2.6%, 1/38). The GⅡ.2[P16] strains isolated were closely related to the 2010-2012 GⅡ.2[P16] strains, from whichi they probably evolved. The GⅡ.2[P16] Qingdao strains shared five common substitutions, namely D173E (motif F), V175I (motif F), S293T, K357Q (motif D), and T360A (motif D). The RdRp nucleotide consistency between GⅡ.2[P16] and GⅡ.4 Sydney[P16] was greater than 95%, and there were mainly four amino acid differences, namely K54R, V125A, A312T, and K457R.The evolutionary variation of GⅡ.2[P16] VP1 was minimal, with only a few amino acid substitutions taking place. The main functional variations of GⅡ.4 Sydney[P16] VP1 included R297H (epitope A), D310N (NERK motif), D372N (epitope A), and R373H (positive selection site).Conclusions:GⅡ.P16 NoV is the predominant epidemic strain of ad norovirus outbreaks in Qingdao from 2016 to 2020, and continuous monitoring of its epidemic trend and in-depth study of its evolutionary mechanism are necessary.

Objective:To analyze the molecular epidemiological characteristics of norovirus (NoV) outbreaks in Qingdao.Methods:Anus swab specimens were collected during NoV outbreaks from 2016 to 2020 and detected by real-time RT-PCR. Full length of RNA-dependent RNA polymerase (RdRp) and VP1 gene were amplified by RT-PCR for sequencing, evolutionary analysis, and homology modeling.Results:A total of 65 NoV outbreaks were reported, with 59 outbreaks occurring in kindergartens and primary/secondary schools, showing a double peak epidemic pattern, with peaks occurring from March to May and from October to December. A GⅡ.P16 outbreak in Qingdao first appeared in March 2017 and became the predominant strains from 2017 to 2020(67.9%, 38/56), including two genotypes: GⅡ.2[P16] (97.4%, 37/38) and GⅡ.4 Sydney[P16] (2.6%, 1/38). The GⅡ.2[P16] strains isolated were closely related to the 2010-2012 GⅡ.2[P16] strains, from whichi they probably evolved. The GⅡ.2[P16] Qingdao strains shared five common substitutions, namely D173E (motif F), V175I (motif F), S293T, K357Q (motif D), and T360A (motif D). The RdRp nucleotide consistency between GⅡ.2[P16] and GⅡ.4 Sydney[P16] was greater than 95%, and there were mainly four amino acid differences, namely K54R, V125A, A312T, and K457R.The evolutionary variation of GⅡ.2[P16] VP1 was minimal, with only a few amino acid substitutions taking place. The main functional variations of GⅡ.4 Sydney[P16] VP1 included R297H (epitope A), D310N (NERK motif), D372N (epitope A), and R373H (positive selection site).Conclusions:GⅡ.P16 NoV is the predominant epidemic strain of ad norovirus outbreaks in Qingdao from 2016 to 2020, and continuous monitoring of its epidemic trend and in-depth study of its evolutionary mechanism are necessary.

After the promulgation and implementation of the Vaccine Administration Law of the People’s Republic of China， the compensation of suspected adverse reactions in China is to be reformed and innovated. There have been attempts at compensation through government finance and insurance， but there has been no precedent for a fund of vaccine-related compensation in China， which means that this could be a new method of solving disputes of compensation for vaccine-related incidences and enhancing public confidence in vaccination. It is suggested that under the current system， we can select a province as a pilot to explore the fund compensation mechanism. The fund comes from special financial allocation， special taxation of vaccine enterprises， fund investment income， charitable donation and other channels. Through a special fund management organization， the independent identification and compensation process can be realized， so as to shorten the current compensation procedure， improve the amount of compensation， ultimately protect the interests of all parties， and promote the steady development of vaccination.

Objective:To investigate the whole genome characteristics of coxsackievirus A4 (CVA4) circulating in Qingdao city.Methods:Four CVA4 isolates circulating in Qingdao city during 2013 to 2015 were selected. Whole genome sequences of these strains were amplified by one-step reverse transcription-polymerase chain reaction (RT-PCR). Sequence alignment and phylogenetic analysis were performed using MEGA7.0 software package. Genetic recombination analysis was performed using similarity plots 3.5.1 software package.Results:Phylogenetic analysis showed that based on the sequences of the whole genome and P1, P2 and P3 regions, HS312/QD/CHN/2013 and HS605/QD/CHN/2014 strains together with the early domestic isolates belonged to the same clade, while FY218/QD/CHN/2015 strain and CV-A4/P1033/2013/China strain collected in Wenzhou in 2013 formed another clade in each phylogenetic tree. HS144/QD/CHN/2014 strain belonged to the same clade as HS312/QD/CHN/2014, HS605/QD/CHN/2014 and the early domestic CVA4 isolates in the phylogenetic tree based on the P1 region, but formed a separate clade in the phylogenetic trees based on the whole genome, P2 region and P3 region. Genetic recombination analysis revealed that there was genetic recombination between HS144/QD/CHN/2014 strain and the CVA2 strain of CV-A2/P373/2013/China isolated in mainland China in 2013 in the region of 2C-3D (5 081-7 301); FY218/QD/CHN/2015 and CV-A4/P1033/2013/China strains were highly homologous and recombination signal sequences were detected in the region of 2A-2B (3 821-4 161) between the two strains and the CVA2 strain of CV-A2/P373/2013/China.Conclusions:The CVA4 isolates circulating in Qingdao city presented obvious genetic diversity at the genome-wide level.

Objective: To analyze the molecular epidemiology of norovirus (NoV) genotype GⅡ.15 in Qingdao City. Methods: One thousand four hundred and twelve stool samples were collected from suspected NoV infected patients and detected by real-time polymerase chain reaction (PCR). Open reading frame (ORF)1-ORF2 and VP1 gene were amplified by reverse transcription (RT)-PCR and sequenced for genotyping, evolutionary analysis and homology modeling. Results: Seven cases of GⅡ.15 type were detected including four sporadic cases and one outbreak.The VP1 gene was highly homologous and had little variation compared with early strain J23/US/1999. The differences of amino acids between strains in Qingdao City were mainly asparagine/asparticacid(N/D)300 and proline/serine(P/S)302.Homology modeling suggested that VP1 of GⅡ.15 strain was composed of S domain and P domain (P1 subdomain included 224-276 and 431-555, P2 subdomain included 277-430). S domain contained eight anti-parallel β-sandwiches and two α-helixes, and P1 subdomain contained one α-helix and seven β-strands, and the P2 subdomain folded into a compact barrel-like structure consisting of six β-strands.Argnine (R)-glycine (G)-valine (V)-motif (289-291) and three specific loci including glutarnine (Q)313, asparagine (N)349 and Q389 were located in the P2 subdomain, with NGR-motif (265-267) located at 22nd upstream of RGV-motif.Site I (SNR-alanine(A)- histidine(H)357-361), Site Ⅱ (D388) and Site Ⅲ (G454, G455) were the main characteristic sites of histo-blood group antigens (HBGA) binding interface, which may be similar to the binding pattern of GⅡ.4 type VA387 and HBGA. Conclusion Although GⅡ.15 type NoV evolves very slowly, it may still have the risk to become an epidemic strain, which needs to be monitored and further studied.

Objective: To investigate the etiology spectrum of hand foot and mouth disease (HFMD) and to analyze the molecular characteristics of Coxsackievirus A10 and A6 in Qingdao in 2014. Methods: Throat swabs of HFMD cases were tested for total enteroviruses (EVs), EV-A71, CV-A16, CV-A10 and CV-A6 by multiplex real time RT-PCR. Other EV serotypes were identified through the sequences of partial VP1 gene. The full-length of VP1 gene of CV-A10 and CV-A6 were amplified and sequenced. The sequences were phylogenetically analyzed using MEGA 5.0 software package. Results: A total of 1727 HFMD patients were detected in 2014 and 11serotypes of enteroviruses were identified. EV-A71(38.0%, 410/1078), CV-A16(28.8%, 311/1078), CV-A10(14.1%, 152/1078)and CV-A6(3.2%, 34/1078)were the most dominant pathogen in 2014 in Qingdao. Proportions of CV-A10 in enterovirus infected children varied dramatically in different ages(χ²=15.19, P=0.001), showing a downtrend with age. Proportion of CV-A10 in inpatients was much higher than that in outpatients(χ²=49.1, P <0.001), while 60% of those inpatients showed nervous system damage symptoms, with pathological reflex or disappearance of physiological reflex. Phylogenetic analysis of complete VP1 sequences showed that all CV-A10 strains identied in this study belonged to genotype C, 71.7% of which located in branch C5; all CV-A6 strains belonged to genotype D while 83.3% of which located in branch D5. Conclusions EV-A71, CV-A16, CV-A10 and CV-A6 were the prevalent pathogens of HFMD in Qingdao in 2014. CV-A10 was more frequently detected in lower age group with HFMD, which can cause damage to nervous system. Strains of branch C5 in genotype C were the dominant strains of CV-A10 circulated in Qingdao in 2014 while strains of branch D5 in genotype D were the major strains of CV-A6.

Carcinoma of pancreatic body and tail is a high invasive disease with a low resectability rate.It was once believed that celiac axis infiltration usually contraindicated resection.Distal pancreatectomy with en bloc celiac axis resection (DP-CAR) is described as a new treatment method of this disease.In recent years,more and more literatures have reported this operation,but they were case reports or small sample retrospective study,the results of which differed according to the different treatments and perioperative managements in different centers.The advantages and disadvantages of DP-CAR are still controversial.Research progress of DP-CAR is reviewed in this article.

Objective To investigate the molecular epidemiological characteristics of hemaggluti-nin (HA) and neuraminidase (NA) of influenza B viruses (IBV) isolated in Qingdao from 2011 to 2018. Methods A total of 12236 samples of influenza-like cases in Qingdao from 2011 to 2018 were collected to extract viral RNAs. All samples were screened for influenza A viruses ( IAV) and IBV by one-step multiplex real-time RT-PCR. Lineages of IBV were identified. One hundred and eighty-two strains of IBV were select-ed to amplify HA and NA genes by RT-PCR and then analyzed by sequencing. Phylogenetic analysis and variation analysis of genes and amino acids were carried out. Results IBV was detected almost every year in Qingdao from 2011 to 2018. The positive rate was only slightly lower than that of IAV ( 4. 99％ vs 6. 21％). B/Victoria linkage had two prominent epidemic years (2011-2012, 2015-2016), while B/Yama-gata linkage had three (2013-2014, 2014-2015, 2017-2018). Most of the infected people were children un-der 10 years old, and the people infected with the two lineages had similar age characteristics. Phylogenetic analysis of HA genes showed clusters in Victoria clades of 1A and 1B and Yamagata clades of 2 and 3. IBV of Yamagata lineage had more amino acid mutation sites than those of Victoria lineage in HA genes with grea-ter genetic diversity. The B/Yamagata strains had 12 amino acid mutations and the B/Victoria strains had seven in four major epitopes. In the receptor binding sites, two amino acid mutations were detected in the B/Yamagata strains and three in the B/Victoria strains. In Qingdao, 26 strains of IBV were intra-lineage reas-sortments, mostly of the B/Victoria lineage, and 23 strains were inter-lineage reassortments, mostly between HA-B/Yamagata and NA-B/Victoria strains. A possible resistant strain to NA inhibitor was found. Conclu-sions The significance of IBV in seasonal influenza should not be neglected. Amino acid substitution, in-sertion/deletion and gene reassortment were the main strategies for the natural evolution of IBV. Influenza surveillance was of great importance and influenza vaccine strains needed to be updated in time.

Objective: To illuminate the gene characteristics and clinical characterization of Coxsackievirus B5 (CV-B5) strains isolated from patients with sevre hand, foot and mouth disease (HFMD) in Qingdao city. Methods: A total of 1 844 patients of HFMD were consecutively admitted to Qingdao Women and Children's Hospital from 2013 to 2014. Information of the study population described above was collected retrospectively. The samples were collected from at least 1 site (throat swab, cerebrospinal fluid), which viral nucleic acid extracted and the entire VP1 gene sequences of CV-B5 isolates were amplified and sequenced, then the homology and phylogeny analysis were conducted by MEGA7.0. The prototype Faulkner strain and other VP1 amino acid sequences were derived from the GenBank database. Results: A total of 8 CV-B5 positive cases were obtained, including 4 males and 4 females; 6 severe hospitalized cases and 2 outpatients. The age of 6 hospitalized patients ranged from 3 to 48 months, with a median of 26 months. For the six inpatients, fever, convulsions vomiting, diarrhea and rash were the main clinical manifestation, and all combined with viral encephalitis. Compared with the prototype strain Faulkner, in the VP1 region,the nucleotide and the amino acid homologies was 77.3%-78.8% and 95.5%-97.0% respectively. Five out of the six severe cases with substitution of serine (S) to asparagine (N) at amino acid site 95 in the VP1 region. The sequences of 8 CV-B5 strains were classified into genogroup D. Conclusion Hand, foot and mouth disease associated with CV-B5 virus infection can result in nervous system involvement and the main complication was viral encephalitis. The CV-B5 strains associated with severe hand, foot and mouth disease had high nucleotide homology and present a certain regional aggregation.

Gastric resection can cause a multifactorial clinical manifestations of dyspepsia,such as flatulence,diarrhea,weight loss,and fat diarrhea.Exocrine pancreatic insufficiency (EPI) is one of the possible mechanisms of fat maldigestion following gastric surgery,the main causes may be related to rapid gastric emptying;asynchrony between gastric emptying and bilio-pancreatic secretion due to new tracts of various reconstructions;bacterial overgrowth after gastrectomy and so on.Oral pancreatic enzyme replacement therapy (PERT) is the mainstay of treatment for EPI,due to lack of available evidence so far,the efficacy and safety of pancreatic enzyme substitution in patients following gastric resection remains unclear and cannot be generally recommended.This review will sum up the revelant studies addressing EPI and PERT after gastric resection in recent years,and summarizes the mechanisms,clinical diagnostic methods and PERT treatment perscription of EPI after gastrectomy to improve the cognition of clinicans.