Genetic characteristics analysis of the hemagglutinin gene of measles virus in Shanghai， 2001‒2018 / 上海预防医学

ObjectiveTo analyze the genetic characteristics of the hemagglutinin （H） gene of measles virus （MeV） in Shanghai， 2001‒2018. MethodsNasopharyngeal swab specimens were collected from suspected measles cases reported in Shanghai from 2001 to 2018， and the isolation of measles virus was conducted with Vero/hSLAM cell line. RT-PCR amplification and sequencing were conducted after RNA extraction to analyze the genetic characteristics of the complete H gene. ResultsIn total， 5 665 nasopharyngeal swab samples were collected by suspected measles case surveillance from 2001 to 2018， and 1 394 measles virus strains were isolated. The homology of nucleotide acid and amino acid among 349 representative measles virus isolates was 87.4%‒100.0% and 85.1%‒100.0%， respectively. The homology of nucleotide acid and amino acid between representative measles virus isolates and China vaccine strain （S191） was 85.7%‒100.0% and 84.1%‒100.0%， respectively. All the sub-genotype H1a MeV isolates had an amino acid substitution （Ser240Asn）， which removed a predicted N-linked glycosylation site. ConclusionMost of the MeV isolates are sub-genotype H1a analyzed based on H gene， which are identical to those of the N gene. The predicted amino acid sequences of the H protein are relatively conserved at most of the functionally significant amino acid positions.

Immunogenicity analysis of sequential inoculation of different strains of poliomyelitis vaccines in Shanghai / 中华预防医学杂志

Objective@#To evaluate the immunogenicity of different strains of inactivated poliomyelitis vaccines (IPV) by sequential program.@*Methods@#This parallel-group controlled trial was conducted in immunization clinics in Shanghai from March 2016 to September 2017. Sabin strains inactivated poliomyelitis vaccines (sIPV), WPV strains inactivated poliomyelitis vaccines (wIPV) and live poliomyelitis Type Ⅰ Type Ⅲ vaccine (bOPV) as the investigational vaccine were used at 2, 3, 4 months old in 325 infants in Shanghai. Infants vaccinated by four sequential program were divided into 4 groups: sIPV+sIPV+bOPV, sIPV+wIPV+bOPV, wIPV+sIPV+bOPV and wIPV+wIPV+bOPV. A total of 230 investigators′ blood samples were collected before primary immunization and 163 investigators′ blood samples were collected after primary immunization. A total of 151 investigators (36, 44, 30 and 41 in each group) finished primary immunization and blood sampling before and after the primary immunization. The geometric mean titer (GMT) of poliovirus typesⅠ and Ⅲ neutralizing antibody was tested and calculated, and the positive results of antibody before and after primary immunization were analyzed.@*Results@#Among the 151 investigators, the age were (2.27±0.61) months and birth weight were (3.27±0.43) kg, and 70 were male. The positive rates of typeⅠwas 98.68% (149 cases), and type Ⅲ was 97.35% (147 cases); the number of investigators tested in each group was 36, 44, 30 and 41, respectively; the positive rates of typeⅠwas 97.22% (35 cases), 100.00% (44 cases), 96.67% (29 cases) and 100.00% (41 cases) (P=0.345); the positive rates of type Ⅲ were 97.22% (35 cases), 95.45% (42 cases), 96.67% (29 cases) and 100.00% (41 cases) (P=0.614).@*Conclusion@#Using sIPV and wIPV simultaneously or alternately for sequential immunization of poliomyelitis vaccines showed good immunogenicity for infants at appropriate age.

Analysis on genetic characteristics of rubella virus isolates from 2011 to 2017 in Shanghai, China / 中华实验和临床病毒学杂志

Objective@#To analyze the molecular epidemiological characteristics of rubella virus wild strains isolated in Shanghai during 2011-2017.@*Methods@#Throat swabs were collected from suspected measles or rubella patients in Shanghai during 2011-2017, which were identified as rubella and excluded measles by laboratory tests. Throat swabs were used to conduct cell culture for rubella virus isolation. After identification by RT-PCR, the nucleic acid of gene E1 of rubella virus was amplified and sequenced, followed by molecular epidemiological analysis.@*Results@#Totally 395 strains of rubella virus were isolated from 684 throat swabs. Compared 377 isolates with the WHO reference strains of all genotypes, phylogenetic tree was constructed based on the amplified 739 nucleotides sequences. These isolates were characterized as two genotypes respectively, 109 strains were defined as genotype 1E which were closer to the WHO reference strain from China (RVi/Shandong.CHN/0.02/), and others were genotype 2B while 5 strains of them were defined as a lineage. Most of the nucleotide mutations were nonsense mutation, and the amino acid sequences were highly conserved. All the genotype 1E rubella viruses except one strain had the same mutation at aa338 site.@*Conclusions@#Two genotypes of rubella virus circulated in Shanghai during 2011-2017.Genotype 1E appeared to be the predominant genotype during 2011-2013, genotype 2B was continuously existing since being found in 2011 and appeared to be the predominant genotype during 2014-2016.

Characterization analysis of gM, gL genes of varicella zoster virus in six provinces of China / 中华预防医学杂志

Objective@#To analyze the genetic characterization of glycoprotein M(gM.),glycoprotein L(gL) of varicella zoster virus.@*Methods@#According to the program of "Ministry of Science and Technology of China" , Based on the 12 suspected VZV patients monitored in Beijing (1 case), Shanghai (5 cases), Jilin (2 cases), Qinghai (1 case), Guangdong (2 case) and Sichuan (case) in 2007-2015. A total of 12 Vesicle fluid and throat swab samples were collected. Positive samples were identified by Agarose gel electrophoresis and two glycoprotein genes were amplified by polymerase chain reaction (PCR). Nucleotide sequences were determined and analyzed by PCR amplification of VZV positive specimens V-OKA-BK of the domestic varicella attenuated live vaccine and the Varilrix-1 of the imported attenuated live vaccine. Nucleotide sequences of VZV positive specimens, vaccine strains (V-OKA-BK, varilrix-1) and GenBank foreign wild strains (41 strains), parent strains (P-oka), vaccine strains (V-oka, Varilrix, Varivax) were compared using BioEdit and MEGA 5.0.@*Results@#12 specimens were VZV positive. Compared with the vaccine strains and the parent strains, the GM gene of 1 positive specimen had radical mutation at 86686 sites, which resulted in amino acid mutation, 5 positive specimens had base mutation at 87844 sites, and 30 strains of foreign wild strains had the same variation at 87 844 sites. 1 positive specimens of gL gene in 101245 sites had base mutation, and led to amino acid mutation, 6 positive specimens at 101624, 101625, 101626 sites had base of loss and the foreign wild strains in these 3 sites had the same variation. Compared with the vaccine strains, the nucleotide and amino acid homology of gM of 12 VZV positive specimens were 99.2%-100% and 98.2%-100%, respectively, and gL of those were 99.3%-100% and 98.6%-100%, respectively. Compared with 41 strains of foreign wild strains, homology of gM's nucleotides and amino acid were 99.3%-100% and 98.5%-100%, respectively; 99.1%-100% and 98.6%-100% for gL. The results of phylogenetic analysis showed that 7 VZV positive samples were on the same branch with 4 vaccine strains and p-oka strain. Based on gL, 12 VZV positive samples were on the same branch as the vaccine strains and p-oka strain.@*Conclusion@#This study demonstrates that the genes of gM, gL are highly conserved and remain stable immunogen, which may be involved in the attenuation of VZV and need to be further researched.

Genotype distribution of human enteroviruses isolated from swage in Shanghai during year 2013-2014 / 中华预防医学杂志

Objective@#To explore the time and genotype distribution of human enterovirus (HEV) isolated from sewage in Shanghai in 2013-2014.@*Methods@#One sewage sample each was collected from two local sewage plants located in Minhang District and Jiading District on the same day at the day 24-28 of every month from 2013 to 2014. Each sample weighed 1 L. The specimens were concentrated by anionic membrane absorption, eluted with beef extract solution, and then used to inoculate RD, HEp-2, and L20B cell lines. A total of 249 enterovirus strains were isolated from sewage samples during the study period, including 185 non-polio enterovirus (NPEV) and 64 poliovirus (PV) strains, which were identified as vaccine strains. RT-PCR and Sanger sequencing were performed to identify HEV genotypes. Homologous analysis of VP1 sequences was conducted using BioEdit (version 7.0.0). Phylogenetic analysis was performed using the neighbor-joining method based on the alignment of VP1 gene sequences using MEGA (version 4.0.2).@*Results@#Among 185 NPEV strains, 178 strains were successfully sequenced and classified into 15 genotypes, including coxsackievirus group B (CVB) 2, 3, and 5; enteric cytopathic human orphan (ECHO) virus 1, 3, 6, 7, 11, 13, 19, 20, 24, 25, and 30; and coxsackievirus group A 4. CVB5 and ECHO6 genotypes accounted for 33.5% (56 strains) and 24.9% (43 strains) of NPEV isolates, respectively. During the study period, HEV isolates were mainly isolated in summer and autumn in Minhang District. ECHO6 strains were frequently isolated from June 2013 to July 2014. Thereafter, the number of ECHO6 strains gradually reduced in the second half of 2014. CVB5 strains demonstrated scattered distribution from 2013 to the first half of 2014 and gradually increased in the second half of 2014. The distribution of ECHO6 and CVB5 strains in Jiading District was similar to that in Minhang District. In 2013-2014, CVB5 strains comprised C6 and C8 subgenotypes, which belong to two transmission chains and show large differences compared with foreign strains isolated during the same period. ECHO6 strains comprised C6, C8, and D9 subgenotypes, which belong to three transmission chains. Moreover, ECHO6 subgenotype D9 was a dominant subgenotype in Shanghai, with broad geographical distribution both at home and abroad.@*Conclusion@#Poliovirus was identified as a vaccine strain in environmental surveillance from June 2013 to April 2014 in Shanghai. Several transmission strains of ECHO6 and CVB5 were identified, which were the dominant serotypes.

Genetic characterization of the isolates of measles viruses in Hongkou district of Shanghai, China in 2012 / 中华流行病学杂志

<p><b>OBJECTIVE</b>To ascertain the genotype of measles viruses isolated in 2012 and genetic characterization of measles viruses in Hongkou district of Shanghai during 2000-2012.</p><p><b>METHODS</b>Measles virus was isolated from throat swab specimens collected from suspected measles cases and 450 bp fragment of C terminus on nucleoprotein (N) gene was amplified by RT-PCR. Sequence analysis was conducted to ascertain the genotype and to compare the difference of nucleotide with other measles virus strain announced by GenBank during 2000-2012. Measles virus genotype was analyzed. Epidemiological investigation was conducted.</p><p><b>RESULTS</b>Phylogenetic analysis showed that 7 measles virus samples were isolated from 34 throat swab specimens with 6 of them belonged to H1 genotype, 1 belonged to D8 genotype of H1 genotype. H1a appeared the main part of Shanghai measles virus. Epidemiological survey showed that D8 was an imported case, also the first case detected since 2000.</p><p><b>CONCLUSION</b>The genotype distribution of measles virus in Hongkou was identified the same as elsewhere in Shanghai. D8 was an imported case, detected for the first time since 2000. The results suggested that viral gene sequencing and genotyping should be regularly conducted at the measles laboratories in Shanghai to strengthen the networking monitoring program of the disease.</p>