Objective: To investigate the epidemiological characteristics of measles outbreak caused by genotype D8 virus in Pinghu city of Zhejiang province, and provide evidence for the control of the outbreak. Methods: The measles outbreak data were collected through National Measles Surveillance System. The outpatient records and admission records were checked, field investigation and outbreak response were conducted. Blood samples in acute phase and swab specimens were collected from the patients for laboratory testing, including serology test, RNA extraction and amplification, measles virus isolation and genotype identification. Software SPSS 17.0 and Excel 2016 were used for data analysis. Results: A total of 10 confirmed measles cases were reported in Pinghu city, and 8 cases were aged >40 years. Six blood samples were collected, in which 5 were measles D8 virus positive and 1 was negative in measles virus detection. There were epidemiological links among 10 cases which occurred in a factory, a hospital and a family at the same time. There was no statistical difference in symptoms among cases caused by D8 virus and H1a virus. After the emergent measles vaccination, the measles outbreak was effectively controlled. Conclusion: Untimely response due to the uneasy detection of measles cases in the early stage, nosocomial infection and weak barrier of measles immunity in adults might be the main reasons for this outbreak. Measles vaccination is effective in the prevention of measles D8 virus infection. It is necessary to strengthen measles genotype monitoring for the tracing of infection source and control of outbreaks.
Adult ; Amplified Fragment Length Polymorphism Analysis ; Child ; Cross Infection ; Disease Outbreaks ; Genotype ; Hospitalization ; Humans ; Measles/virology* ; Measles virus/isolation & purification* ; Outpatients ; Population Surveillance ; RNA, Viral/genetics* ; Sequence Analysis, DNA

This study aims to investigate the genetic characteristics of hemagglutinin in wild-type measles viruses in Henan Province, China and to provide a basis for measles control and elimination. Specimens were collected from suspected measles cases in Henan during 2008-2012. Cell culture was performed for virus isolation, and RT-PCR was used to amplify hemagglutinin gene. The PCR products were sequenced and analyzed, including construction of phylogenetic tree and analysis of the distance between the isolated virus and the reference virus; then, the variations in predicted amino acids were analyzed. The results showed that 12 measles viruses were isolated in Henan Province and identified as H1a genotype; the nucleotide and amino acid homologies were 98.0%-100% and 97.2%-99.8%, respectively. One glycosylation site changed in all the 12 sequences because of the amino acid mutation from serine to asparagine at the 240th site, as compared with Edmonston-wt. USA/54/A. Overall, the wild-type measles virus genotype circulating in Henan Province from 2008 to 2012 was H1a, with high homology between strains; there were some variations in amino acid sequences, resulting in glycosylation site deletion.
China ; Hemagglutinins ; genetics ; Humans ; Measles ; virology ; Measles virus ; classification ; genetics ; isolation & purification ; Molecular Sequence Data ; Phylogeny ; Viral Proteins ; genetics

We isolated and identified the genotypes and molecular characteristics of the imported B3 measles virus (MeV) in the Chinese mainland. The Vero/SLAM cell line was used to isolate the viruses. Reverse transcription-polymerase chain reaction was undertaken to amplify the 450 nucleotide acids of the 3-terminal of the nucleoprotein gene. A phylogenetic tree was constructed and similarities in homology assessed. Results suggested that the Shanghai isolates MVi/Shanghai. CHN/38. 13/02 [B3] and MVi/Shanghai. CHN/40. 13/02[B3] were clustered within the same genotype group as the World Health Organization (WHO) B3 genotype reference strain. The number of differences in nucleotide acids between the two Shanghai isolates was one. The homology of nucleotide acids between the Shanghai isolates and the WHO B3 genotype reference strain (MVi/Ibadan. NGA/0.97/1/B3) was 98%. Comparative results from the Measles Nucleotide Surveillance system suggested that the sequences of Shanghai isolates and the 2013 vi- ruses from Australia, Japan, Korea, Hong Kong China, Philippines and Iran were identical. This is the first time that the B3 genotype of MeV in the Chinese mainland has been isolated since 1993. These data can be used to create a "baseline" of genetic information for measles viruses in China, and help to trace the transmission of measles viruses in China and the rest of the world.
China ; Genotype ; Humans ; Measles ; virology ; Measles virus ; classification ; genetics ; isolation & purification

OBJECTIVETo investigate the variations on hemagglutinin (H) gene of measles virus (MV) in Zhejiang province, and to analyze the differences with strains circulated both at home and abroad.

METHODSIn total, 33 MV strains isolated in Zhejiang province between 1999 and 2011 were collected.RNA of the isolated MV strains was extracted and the complete sequences on H gene were amplified using RT-PCR assay. The products were compared with the Chinese vaccine strain Shanghai-191, which was downloaded from GenBank, and other 95 different MV strains from all over the world.

RESULTS33 MV strains, isolated from the throat swab specimens collected from MV patients in Zhejiang province during 1999 to 2001, were used to conduct phylogenetic analysis with MV strains circulated in other areas of China during 1993 to 2007. The phylogenetic tree based on H gene sequences showed that all the Zhejiang MV strains located in H1a cluster, and no apparent time series and geographic restrictions were observed. Compared to the referenced vaccine strain Shanghai-191, the average variation rate on nucleotides and amino acids, and the evolutionary rate of H1a viruses from China during 2003 to 2011 were separately 5.15%, 4.44% and 5.81%, which were higher than the rates of H1a viruses during 1965 to 1993 (4.75%, 3.86% and 5.30%), and the rates of viruses during 1994 to 2002 (4.80%, 4.08% and 5.37%).However, the dn/ds ratios of strains within the three time periods were 0.19,0.21 and 0.23 respectively, which indicated that no evidence of positive selection was found on H1a MV strains during 1993 to 2011. A 24 stable amino acid variation sites on H gene was found between H1a viruses during 2003 to 2011 and the vaccine strain Shanghai-191. The largest variation occurred between vaccine and H1a strains, with 0.053 of the p-distance and 26-28 of amino acid mutations.However, only 15 stable amino acid variations were found between vaccine strain and genotype B3 or D4 strains.In addition, significant differences were found between H1a viruses and genotype B or D viruses, with 0.074 and 0.071 of p-distance and 27-33 of amino acid differences.

CONCLUSIONSignificant differences were found on H gene between MV strains subtype H1a and vaccine strains and other genotype strains. The variations were enlarged with the time coursing; therefore, the surveillance on variation of Chinese MV strains should be taken into account.

China ; epidemiology ; Genotype ; Hemagglutinins, Viral ; genetics ; Humans ; Measles ; epidemiology ; virology ; Measles virus ; classification ; genetics ; isolation & purification

This study analyzed the genetic characterization on first imported measles virus of genotype D8 in Chinese mainland. Serums were collected from the suspicious MV patients to detect IgM antibody in ELISA. Throat swabs were cultured in Vero/SLAM cell line to get measles virus isolates. Part of the nucleotide sequence of the 3' terminus of nucleoprotein (N) gene of these isolates were amplified by RT-PCR, and the amplicons were directly sequenced. The phylogenetic analysis was based on the nucleotide sequence about 456 base pairs of the 3' terminus of nucleoprotein (N) gene. Results showed that it reported 1 105 suspicious measles cases in shanghai, 2012, including 590 confirmed cases and 2 clinical case. The reported morbidity was 2.52 per one hundred thousand. 247 measles viruses were isolated from 984 throat swabs specimen. Most of them belonged to sub-genotype H1a except Shanghai12-239 was genotype D8. The homology of nucleotide and amino acid sequences were 97.8% and 98.6% respectively between Shanghai12-239 and WHO reference strain (Manchester. UNK30.94(D8)AF280803). Those were 89.6%-94.5% and 88.7%-95.3% between Shanghai12-239 and WHO reference strains of other genotypes.
Adolescent ; Adult ; Aged ; Child ; Child, Preschool ; China ; Female ; Genotype ; Humans ; Infant ; Male ; Measles ; virology ; Measles virus ; classification ; genetics ; isolation & purification ; Middle Aged ; Molecular Sequence Data ; Phylogeny ; Travel ; Viral Proteins ; genetics ; Young Adult

OBJECTIVETo identify wild measles virus and vaccine virus by detection nucleic acid of clinical samples from measles patients with immunization history circulating in Beijing through multiplex real-time fluorescent PCR technology.

METHODSFrom July 2011 to February 2012, 10 throat swabs and 15 urine specimens were collected from 16 suspected measles patients who were 8 - 9 months old infants with immunization history in Beijing. The specificity of multiplex real-time fluorescent PCR was firstly tested by measles vaccine virus, wild virus and other respiratory virus. Then the vaccine virus and wild virus were titrated and diluted to test the sensitivity of the PCR method. The result was then compared with it analyzed by PCR-RFLP method. Meanwhile, the clinical sample of the measles patients were tested and confirmed by sequencing method.

RESULTSThe primer-probe sets of Fam, Joe and Cy5 showed great specificity of measles virus, and could distinguish the measles vaccine virus and wild virus well. The sensitivity of this method to detect measles vaccine virus reached 0.1 CCID(50)/0.1 ml; and the sensitivity to wild virus reached 0.006 CCID(50)/0.1 ml; which were both higher than the sensitivity of PCR-RFLP method. Out of the 16 measles patients with vaccination history, 3 were negative and the other 13 all belonged to measles virus genotype A, and were confirmed to be vaccine virus by sequencing method.

CONCLUSIONMultiplex real-time PCR method is accurate, rapid and sensitive to identify measles vaccine virus and wild virus. The method could greatly help us to find measles patients and to identify the vaccine-related cases.

China ; epidemiology ; DNA Primers ; Humans ; Infant ; Measles Vaccine ; Measles virus ; classification ; genetics ; isolation & purification ; Multiplex Polymerase Chain Reaction ; RNA, Viral ; genetics ; Sensitivity and Specificity

Measles and rubella virus cause fever rash diseases that are uneasy to differentiate clinically from each other. Specific primers and fluorescence-labeled probes were designed, and a multiplex Real-time RT-PCR with an internal control was developed to simultaneously identify the measles and rubella virus. The multiplex Real-time RT-PCR assay was specific and no false positive or false negative results were found. The sensitivity of the assay was 0.1TCID50/mL and 1TCID50/mL for measles and rubella virus respectively. Analysis with 0.1-10(3)TCID50/mL measles or rubella virus samples demonstrated high validity and reproducibility with the coefficient of variability(CV) of below 0.9% for both measles and rubella virus. Using ribonuclease P (RNase P) as internal false negative control, the developed multiplex Real-time RT-PCR assay is suitable for rapid clinical diagnosis of measles and rubella virus.
Fluorescent Dyes ; Humans ; Measles ; diagnosis ; virology ; Measles virus ; genetics ; RNA, Viral ; genetics ; isolation & purification ; Reproducibility of Results ; Reverse Transcriptase Polymerase Chain Reaction ; methods ; Ribonuclease P ; genetics ; Rubella ; diagnosis ; virology ; Rubella virus ; genetics ; Sensitivity and Specificity

OBJECTIVETo ascertain the genetic characterization and genotype of measles viruses isolated in Shanghai region, in 2005.

METHODSMeasles virus was isolated from throat swab specimens collected from suspected measles cases and 450 bp fragment of C terminus of nucleprotein (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 published in GenBank.

RESULTS4 measles viruses were isolated from 10 throat swab specimens, and the sequence analysis indicated that they belonged to H1 genotype. The homogeneity of 450 nucleotides in the C terminal of the N gene was at 98%-98.2% as compared to H1 genotype (China93-7). They differed from genotype H2 (China94-1) at 6.4%-6.9% and from genotype A (Edmonston) at 6.7%-6.9%, from measles vaccine (Shanghail91) at 7.6%-8.0%. They differed from the other measles viral strain isolated in China in 1993 - 2005 at 0.2%-3.7%. The variation within 4 isolated measles viruses was at 0.7%-1.3%.

CONCLUSIONIt was H1 genotype measles viruses,which are the native viruses in China that led to the outbreak of measles in Shanghai, in 2005.

China ; epidemiology ; Disease Outbreaks ; Genotype ; Humans ; Measles ; epidemiology ; genetics ; Measles virus ; genetics ; isolation & purification ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Analysis, DNA

OBJECTIVETo analyze the affecting factors on the cause of measles and measles vaccine under the high coverage of measles vaccine in Shaanxi province.

METHODSAge distribution and vaccination history on measles cases were studied. Throat swabs were obtained from measles cases. Measles virus was isolated from collected specimens with phenol-chloroform extraction method. Amplification was performed by RT-PCR in order to amplify 450 bp fragment of the -COOH side of N gene,and then the sequences of PCR products were detected to confirm the gene type of measles virus. Sera were obtained from patients who were in acute phase of measles disease,and antibody titer against measles vaccine strain and wild strain were determined by small amounts neutralization test.

RESULTSMeasles cases with the history of measles vaccination were accounted for 38.97% of the total numbers. The geometrical mean titer (GMT) (56.18) against S191 attenuated strain was significant higher than that of wild strain (26.90) among these measles patients with history of having received measles vaccination. The GMT (25.40) against S191 attenuated strain was similar to that of wild strain (27.86) among these measles patients with non-history of measles vaccination. The antibody negative rate against wild strain was 19.15% to these sera from patients with the history of measles vaccination and antibody potency against S191 strain was less than 16.

CONCLUSIONThe appearance of higher measles incidence under the higher coverage of measles vaccine indicated that measles epidemic strain might degenerate as the result regarding the failure of the present measles vaccine in protecting the transmission of H1 wild strain.

Age Distribution ; Antibodies, Viral ; blood ; Base Sequence ; China ; epidemiology ; Disease Outbreaks ; prevention & control ; Humans ; Incidence ; Measles ; epidemiology ; prevention & control ; Measles Vaccine ; administration & dosage ; Measles virus ; genetics ; isolation & purification ; Molecular Sequence Data ; Neutralization Tests

OBJECTIVETo study the genetic characterization of wild-type measles viruses isolated in Xinjiang in 2003 and 2004.

METHODSPeripheral blood mononuclear cells (PBMC) from 19 suspected measles cases collected between June 2003 and April 2004 were used to isolate measles virus by cocultivation with phytohemagglutinin (PHA)-stimulated cord blood mononuclear cells (CBMC). For positive samples, 676 nucleotides of the C-terminus of the nucleoprotein (N) gene of the measles virus genome were amplified by reverse transcription-polymerase chain reaction and then sequenced. These sequences were compared with those of other measles reference strains available in GenBank or measles isolates elsewhere in China using BLAST searches and phylogenetic analyses.

RESULTS6 measles virus strains were isolated with 3 strains (XJ03-26, XJ03-27, XJ03-74) from 2003 and 3 (XJ04-146, XJ04-150, XJ04-152) from 2004. The strain XJ03-26, differed from the Chinese measles vaccine strain S-191 (genotype A) by less than 1% at nucleotide level, and therefore appeared a vaccine-associated strain. The other 5 strains as XJ03-27, XJ03-74, XJ04-146, XJ04-150 and XJ04-152 were proved to be genotype H1 strains,among which XJ03-27, XJ03-74, XJ04-150 and XJ04-152, showing their nucleotide diversity were varied from 0.5% to 1.6%, when compared to the H1a reference strain China9322, and identified as H1a strains. XJ04-146 showed a nucleotide similarity of 98.7% when compared to H1b reference strain China9475, and was identified as H1b strain. Additionally, we found that there were two sets of strain (XJ03-27 and XJ04-150; XJ03-74 and XJ04-152), with almost identical nucleotide sequences, circulating in 2003 and 2004 and both having more nucleotide variability (up to 6.1%, 27 nucleotides).

CONCLUSIONGenotype H1 measles virus had been proven to have been circulated in Xinjiang, China during 2003 and 2004. H1a was the predominant epidemic strain while H1b strain stood the next.

China ; epidemiology ; Disease Outbreaks ; Genotype ; Humans ; Measles ; epidemiology ; Measles virus ; classification ; genetics ; isolation & purification ; Nucleoproteins ; genetics ; Phylogeny ; RNA, Viral ; genetics ; Sequence Analysis, RNA ; Viral Proteins ; genetics