[The pathogenic spectrum of hand, foot and mouth disease and molecular characterizations of human enterovirus 71 in Inner Mongolia autonomous region in 2010].

To study the pathogenic spectrum of hand, foot and mouth disease (HFMD) and the molecular characterizations of human enteroviruses 71 (HEV71) isolated from the clinical specimens of HFMD patients in Inner Mongolia in 2010. A total of 921 clinical specimens including stools and throat swabs were collected from HFMD patients in outpatient service in Inner Mongolia and then viral isolation was performed, the positive viral isolates were identified by using the real-time PCR method (detecting EV, HEV71 and CVA16 in a single tube), and VP4 and VP1 coding region amplification and sequencing was performed with the viral isolates that were identified as non-HEV71, non-CVA16 HEVs. A total of 153 viruses were isolated form 921 clinical specimens, the positive rate was 16.61%, of which 61 (39.87%) were HEV71, 82 (53.59%) were CVA16, 7 (6.53%) were other HEVs(6 were CVB4 and 1 was polio vaccine virus type II) and 3 (1.96%) were adenoviruses. Nine viruses were isolated from severe cases, of which 6 were HEV71 and 3 were CVA16. Thirty two HEV71 isolates were selected from the patients presenting mild symptoms and the patients presenting severe symptoms randomly, and the VP1 coding regions of represented HEV71 isolates were amplified and sequenced. Finally the phylogenetic tree was constructed among the VP1 coding regions of the different genotypes and subgenotypes of HEV71 strains. The nucleotide acid and amino acid of 32 represented HEV71 strains in Inner Mongolia were closed to HEV71 strains isolated from mainland China since 2007, especially from Beijing in 2008, and it showed that all HEV71 strains clustered within the C4a evolution branch of C4 subgenotype. There was slight difference in the nucleotide and the amino acid sequence in VP1 region among the 32 Inner Mongolia HEV71 strains, the identity were 96.4%-100% and 98.14%-100%, respectively, and there was a little difference in the nucleotide acid sequence between the HEV71 strains from Inner Mongolia in 2010 and in 2007, the identity was from 96.95% to 97.87%. Thirty two HEV71 strains were in different lineages in the phylogenetic tree, and it indicated that these strains belonged to many different viral transmission chains. HEV71 and CVA16 were the main pathogens of HFMD in Inner Mongolia in 2010 and most severe cases were caused by HEV71. All the HEV71 strains circulated in Inner Mongolia belonged to C4a evolution branch within C4 subgenotype. Phylogenetic analysis revealed that 2010 Inner Mongolia HEV71 strains were located in different lineages, and had more nucleotide identity with 2008 Beijing HEV71 strains than with 2007 Inner Mongolia HEV71 strains. This indicated that Inner Mongolia HEV71 strains had not evolved independently, but co-evolved with the HEV71 strains in other provinces in mainland China.

Safety and immunogenicity of 2009 pandemic influenza A H1N1 vaccines in China: a multicentre, double-blind, randomised, placebo-controlled trial.

BACKGROUND: The current influenza pandemic calls for a safe and effective vaccine. We assessed the safety and immunogenicity of eight formulations of 2009 pandemic influenza A H1N1 vaccine produced by ten Chinese manufacturers. METHODS: In this multicentre, double-blind, randomised trial, 12 691 people aged 3 years or older were recruited in ten centres in China. In each centre, participants were stratified by age and randomly assigned by a random number table to receive one of several vaccine formulations or placebo. The study assessed eight formulations: split-virion formulation containing 7.5 microg, 15 microg, or 30 microg haemagglutinin per dose, with or without aluminium hydroxide adjuvant, and whole-virion formulation containing 5 microg or 10 microg haemagglutinin per dose, with adjuvant. All formulations were produced from the reassortant strain X-179A (A/California/07/2009-A/PR/8/34). We analysed the safety (adverse events), immunogenicity (geometric mean titre [GMT] of haemagglutination inhibition antibody), and seroprotection (GMT >or=1:40) of the formulations. Analysis was by per protocol. Two sites registered their trial with ClinicalTrials.gov, numbers NCT00956111 and NCT00975572. The other eight studies were registered with the State Food and Drug Administration of China. FINDINGS: 12 691 participants received the first dose on day 0, and 12 348 participants received the second dose on day 21. The seroprotection rate 21 days after the first dose of vaccine ranged from 69.5% (95% CI 65.9-72.8) for the 7.5 microg adjuvant split-virion formulation to 92.8% (91.9-93.6) for the 30 microg non-adjuvant split-virion formulation. The seroprotection rate was 86.5% (796 of 920; 84.1-88.7) in recipients of one dose of the 7.5 microg non-adjuvant split-virion vaccine compared with 9.8% (140 of 1432; 8.3-11.4) in recipients of placebo (p<0.0001). One dose of the 7.5 microg non-adjuvant split-virion vaccine induced seroprotection in 178 of 232 children (aged 3 years to <12 years; 76.7%, 70.7-82.0), 211 of 218 adolescents (12 years to <18 years; 96.8%, 93.5-98.7), 289 of 323 adults (18-60 years; 89.5%, 85.6-92.6), and 118 of 147 adults older than 60 years (80.3%, 72.9-86.4), meeting the European Union's licensure criteria for seroprotection in all age-groups. In children, a second dose of the 7.5 microg formulation increased the seroprotection rate to 97.7% (215 of 220, 94.8-99.3). Adverse reactions were mostly mild or moderate, and self-limited. Severe adverse effects occurred in 69 (0.6%, 0.5-0.8) recipients of vaccine compared with one recipient (0.1%, 0-0.2) of placebo. The most common severe adverse reaction was fever, which occurred in 25 (0.22%; 0.14-0.33) recipients of vaccine after the first dose and four (0.04%; 0.01-0.09) recipients of vaccine after the second dose compared with no recipients of placebo after either dose. INTERPRETATION: One dose of non-adjuvant split-virion vaccine containing 7.5 microg haemagglutinin could be promoted as the formulation of choice against 2009 pandemic influenza A H1N1 for people aged 12 years or older. In children (aged <12 years), two 7.5 mug doses might be needed. FUNDING: Sinovac Biotech, Hualan Biological Bacterin, China National Biotec Group, Beijing Tiantan Biological Products, Changchun Institute of Biological Products, Changchun Changsheng Life Sciences, Jiangsu Yanshen Biological Technology Stock, Zhejiang Tianyuan Bio-Pharmaceutical, Lanzhou Institute of Biological Products, Shanghai Institute of Biological Products, and Dalian Aleph Biomedical.

[Study on the epidemiological characteristics of hemorrhagic fever with renal syndrome in Inner Mongolia].

OBJECTIVE: In order to better understand the epidemiological features of Hantviruses in Inner Mongolia. METHODS: Epidemiological surveillance data during the period of the past 52 years were analyzed. An epidemiological survey was carried out in the main epidemic areas in 2005. RESULTS: A total of 8310 hemorrhagic fever with renal syndrome (HFRS) cases were reported in Inner Mongolia from 1955 to 2006, and distributed in 61 counties. HFRS cases were mainly distributed in the east part of Inner Mongolia before 1990. However, HFRS cases had occurred in the middle and western parts since 1990. Hulunbeier prefecture, from the eastern part of Inner Mongolia, had been the most severe area being hit by HERS since the first outbreak in 1955, with 7369 cases reported over the past 52 years, and accounted for 88.68% of the total cases in the whole autonomous region. Although no HFRS cases had been reported before 1999 in Bayannaoer which located in the western part of Inner Mongolia, a total of 95 cases were reported in 2005. Hantavirus antigens had been detected in 11 species of rodents so far,including Apodemus agrarius, Rattus norvegicus, Mus Musculus, Cricetulus barabensis, meriones meridianus, Microtus maximowiczii , Clethrionomys rutilus, Apodemus peninsulae, Phodopus roborvskii, Dipus sagitta and Allactaga sibirica. CONCLUSION: Results suggested that the epidemics might remain at a relatively high level in the years to come in Inner Mongolia. Furthermore, there might be other types of Hantaviruses in addition to the already identified Seoul viral type in this area.