Analysis of hemagglutinin-neuraminidase gene characteristics of human parainfluenza virus type 3 among children with acute respiratory tract infection in Qingdao city / 中华预防医学杂志

The purpose was to discuss the infection status of human parainfluenza virus type 3 (HPIV-3) in children with acute respiratory tract infection(ARTI) in Qingdao, Shandong province, and to analyze the gene characteristics of HPIV-3 hemagglutinin-neuraminidase protein (HN). This study was a cross-sectional study. A total of 1 674 throat swab samples were collected randomly from children with ARTI, in the three hospitals (Qingdao Women and Children's Hospital, West Coast Branch of Affiliated Hospital of Qingdao University, Laoshan Branch of Affiliated Hospital of Qingdao University) from January 2018 to December 2019. Multiplex real-time fluorescence RT-PCR was performed to screen HPIV-3 positive specimens. For HPIV-3 positive specimens, nested PCR was used to amplify the full-length HN gene of HPIV-3. The HN gene was sequenced and compared with the representative strains of HPIV-3 in GenBank, and the phylogenetic tree was established. As results, this study collected 1 674 samples, in which there were 90 HPIV-3 positive samples showed and the detection rate was 5.37%. Among positive specimens, the number of samples from children under 6 years old was 88, accounting for 97.78%. HPIV-3 positive cases were mainly distributed in spring and summer. The full-length sequences of 44 HPIV-3 HN genes were obtained by nested PCR method. Sequence alignment and evolutionary analysis showed that the HPIV-3HN gene belonged to the C3a and C3b branches of C3 genotype, with 30 strains of subtype C3a and 14 strains of subtype C3b. The nucleotide and amino acid homology of the amplified 44 strains of the HPIV-3 HN gene in Qingdao were 97.0%-100.0% and 98.5%-100.0%, respectively. In conclusion, from 2018 to 2019, the C3a and C3b branches of HPIV-3 C3 genotype were circulating prevalent in Qingdao, Shandong province. HN gene variation rate was low, but showed certain regional characteristics in evolution.

Etiology spectrum of virus in acute upper respiratory infection in children from 2017 to 2018 in Qingdao / 中华疾病控制杂志

Objective To understand the prevalence and epidemiological characteristics of respiratory viruses in influenza-like illness in children during March 2017 to March 2018 in Qingdao. Methods A random selection of influenza surveillance cases (influenza-like illness, ILI) among children in Qingdao area was selected as the research object, and 359 cases were detected. Nasopharyngeal swabs were collected for multiple-fluorescence real-time reverse transcription-polymerase chain reaction nucleic acid detection to screen 9 kinds of respiratory viruses. Results Among the 359 Cases, 200 cases were positive for at least 1 kinds of viruses, and the positive rate was 55.71%(200/359). Among these 200 cases, the most positive numbers were influenza B Yamagata (IVB Yamagata) 29.50%(59/200), followed by enterovirus 15.00%(30/200), respiratory adenovirus (AdV) 13.50%(27/200), respiratory syncytial virus A (RSVA) 12.5%(25/200), influenza A H1N1(IVA H1N1) 10.00%(20/200), etc. 2 cases were 3 kinds of mixed viruses infected and 1 case was 4 kinds of mixed viruses infected. Conclusions Nine kinds of respiratory viruses are prevalent in Qingdao during March 2017 -March 2018. The main prevalence viruses contain influenza B Yamagata, enterovirus, respiratory adenovirus, respiratory syncytial virus A, influenza A H1N1. There is obvious seasonal distribution of influenza, respiratory syncytial virus, enterovirus, metapneumovirus. A mixed infection exists between 9 kinds of respiratory viruses, and mixed infection occurs in the month of the virus epidemic.

Analysis of characteristics of whole-genome of influenza A H1N1 virus in Qingdao between year 2009 and 2011 / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate characteristics of the whole-genome of influenza A H1N1 virus circulated in Qingdao from year 2009 to 2011.</p><p><b>METHODS</b>RNA of 35 influenza A H1N1 virus isolates circulated in Qingdao between year 2009 and 2011 was extracted and all segments were amplified by RT-PCR. The sequence was then detected and assembled by software Sequencher.25 HA full-length sequences published on GenBank were selected as reference. While MEGA 5.0 software package was explored for phylogenetic analysis to characterize the molecular feature with reference to the whole-genome sequence and the hemagglutinin (HA).1068 HA sequences of influenza A H1N1 virus isolated worldwide from August 2010 to March 2011 were downloaded for amino acid mutation analysis.</p><p><b>RESULTS</b>On the HA genes phylogenetic tree, the virus were separately divided into 4 clades in 2009-2010 and 2010-2011 surveillance season, each with a preponderant epidemic clade. The homogeneity of nucleotide and amino acids of HA isolates were 99.6%-99.9% and 99.1%-99.8% respectively in 2009-2010 surveillance season; 99.1%-99.6% and 98.2%-99.1% respectively in 2010-2011 surveillance season. The homogeneity of nucleotide and amino acids of the preponderant isolates were separately 98.8%-99.8% and 98.0%-99.6%. Compared with the vaccine strain, there were separately 14 and 12 variant amino acids of virus HA in the two surveillance season, involving 10 antigen sites and 5 positive selected sites. The sequence analysis of neuraminidase protein showed that the positions 247, 274 presented serine and histidine(S247, H274) respectively. The sequence analysis of M2 protein showed that the isolated A H1N1 viruses presented asparagine in amino acid site 31 (N31).</p><p><b>CONCLUSION</b>All the A H1N1 influenza virus circulated in Qingdao from year 2009 to 2011 presented continual variation and therefore caused antigenic drift. All the isolations were adamantane-resistance, but susceptible to inhibitors of neuraminidase.</p>

Analysis of evolution features of whole genome of influenza virus H3N2 in Qingdao between year 2007 and 2011 / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the evolution features of whole-genome of influenza virus H3N2 prevalent in Qingdao from year 2007 to 2011.</p><p><b>METHODS</b>The RNA of 58 strains of influenza virus H3N2 prevalent in Qingdao between 2007 and 2011 was extracted and all segments amplified by RT-PCR. The sequence was then detected and assembled by software Sequencer. A total of 589 strains of influenza virus H3N2 with more than 300 amino acid recorded by GenBank were selected. The phylogeny and molecular features of all gene segments were analyzed by software Mega 5.0, referred by the heavy chain of hemagglutinin (HA1).</p><p><b>RESULTS</b>Hemagglutinin (HA) genes of influenza virus H3N2 prevalent in Qingdao between year 2007 and 2011 formed a single trunk of phylogenetic tree. Every prevalent strain originated in last season. The analysis of the evolution of whole genome found that reassortment virus strains were prevalent between year 2009 and 2010, but between 2010 and 2011 there were two series of prevalent strains, which showed complicated reassortment. Compared with the vaccine strains, the variant amino acids of protein of virus HA1 between year 2007 and 2011 were 8, 6, 6, 8 and 11, involving 13 antigenic sites. The sequence analysis of M2 protein showed that the isolated influenza virus H3N2 mutated in amino acid site 31, from serine to asparagine (S31N). HA1 gene of influenza virus H3N2 isolated in Qingdao between 2007 and 2011 shared the similar phylogenetic tree with the globally prevalent strain. The comparison of the sequence and the analysis of the antigenicity found co-infection between H3N2 and A/H1N1 in the strain A/Qingdao/F521/2011.</p><p><b>CONCLUSION</b>The evolution features of all segments of influenza virus H3N2 prevalent in Qingdao between year 2007 and 2011 were complicated.</p>

Molecular epidemiology of human enterovirus 71 strains in Qingdao region,Shandong province,2007-2009 / 中华流行病学杂志

Objective To study the molecular epidemiology of human enterovirus 71(EV71)isolated from patients with hand-foot-mouth disease(HFMD) in Qingdao region between 2007 and 2009.Methods Throat swabs of HFMD were detected for total enterovirus(EV),EV71and CA16 by fluorescence reverse transcription-polymerase chain reaction(RT-PCR).The VP1 region was amplified from positive EV71 specimens and 51 nucleotide sequences of VP1 gene were successfully sequenced.EV71 genotypes were characterized by phylogenetic analysis.Results 51Qingdao EV71 strains identified between 2007 and 2009 belonged to C4a cluster of subgenotype C4and 5.3%nucleotide divergence and 1.7%amino acid divergence were found among them.The strains in 2008 and 2009 were respectively divided into several lineages on phylogenetic flees but there was a main lineage(namely prominent strain)every year.The Qingdao prominent strains identified in 2008had high identities with the Linyi prominent strains in 2007.The Qingdao prominent strains in 2009and the secondary prominent strains in 2008 had high identities with the Fuyang prominent strains in 2008.Two Qingdao strains in 2007 had high identities with the Linyi popular strains in 2007.Conclusion Data showed that several EV71 transmission chains were co-circulating in Qingdao between 2008 and 2009.The main transmission chain in 2008 became the minor one but the minor transmission chain in 2008 was transferred into the main transmission chain in 2009.

Interventional effect of vitamin A supplementation on re-vaccination to hepatitis B virus among rural infants and young children in China / 中华预防医学杂志

<p><b>OBJECTIVE</b>The objective of this study was to observe the interventional effect of cod liver oil supplementation on re-vaccination to hepatitis B virus (HBV) among infants and young children.</p><p><b>METHODS</b>All 7-36 months old infants and young children, who had been vaccinated with obligatory HBV vaccines routinely by the national technical and administrative procedures for HBV vaccination on children of China, were convened among villages in Linyi, Shandong province, from October 2008 to March 2009. After detection of serum anti-HBV, one hundred children with lower serum anti-HBV were picked out for the randomized, double blinded, placebo controlled vitamin A supplementation study. The children in the intervention group (50 subjects) took 0.5 g condensed cod liver oil (containing 25 000 IU vitamin A and 2500 IU vitamin D(2)) every 15 days for six times. The children in the control group (50 subjects) were given corn oil with same volume. All children were re-vaccinated at the 30th and the 60th day of the experiment. The serum samples were collected from each child at the 90th day of the experiment. Retinol concentration in serum samples was analyzed with HPLC method before and after the intervention. The levels of serum anti-HBs were detected by the electro-chemi-luminescence immunoassay (ECLIA).</p><p><b>RESULTS</b>Total 74 children finished the supplemental experiment and blood collection, 37 subjects in each group, respectively. After intervention, the serum retinol level in the experimental and control group were (404.1 ± 123.1) and (240.8 ± 92.8) µg/L (t = 6.441, P < 0.01), respectively. The serum anti-HBs levels in the experimental and control group were (2737.2 ± 2492.6) and (1199.7 ± 2141.6) U/L (t = 2.846, P < 0.01), respectively. The rate of weak or no-answer case in experimental and control groups was 0.00% (0/37) and 10.81% (4/37) (χ(2) = 4.229, P = 0.040), respectively.</p><p><b>CONCLUSION</b>The results showed that vitamin A supplementation might enhance the re-vaccination reaction against HB vaccine in infants and young children.</p>

Etiology of hand, foot and mouth disease in Qingdao during 2008-2009 / 病毒学报

An etiology study on HFMD in Qingdao region during 2008-2009 was conducted. The virus RNA were isolated from throat swabs of HFMD,the EV, EV71 and CVA16 were detected by multiplex realtime RT-PCR. For those specimens with EV positive and both EV71 and CVA16 negative,a reverese transcription-seminested polymerase chain reaction (RT-snPCR) was perfomed to amplify part sequence of the VP1 gene for sabsequent analysis to identify the serotype. The results indicated that EV71 and CVA16 were the major pathogens of HFMD in Qingdao during 2008-2009. The proportion of EV71 was greater than CVA16 in either mild or serious HFMD cases. Sequence analysis showed that 5 non-EV71 and non-CVA16 serotypes (8 specimens) were obtained in 2008 including Coxsackievirus A5, A6, A10, A12 and Echovirus 9, which were well distributed. Three serotypes(13 specimens) were obtained in 2009 including Coxsackievirus A9, A12 and B2, of which CVA12 was of a big proportion (11/13). CVA12 became a new relatively major pathogen of HFMD in Qingdao during 2009.