| ObjectiveTo examine the epidemiology of influenza-like illness (ILI) sentinel surveillance in 13 cities of Jiangsu province during 2010-2014. To explore the prevalence of influenza, epidemic trends and prevention measures for potential flu outbreak or epidemic issue timely early warnings, in Jiangsu Province. Further, to analyze the genetic characterization of whole-genome of influenza A/H1N1(09pdm) viruses in Jiangsu province between 2010-2014. Understand the molecular genetic characteristics of A/H1N1 (09pdm), and provide a scientific basis for vaccine development.Methods(1) Test and Data AcquisitionAccording to "National Influenza(Influenza A/H1N1) surveillance program" requirement, cases Sample of influenza were defect by using throat swabs. After divided the virus positive samples, culture and ssubtype identification, and case information and entered outcome of of the National Influenza Surveillance Network Monitoring System.Randomly we selected influenza sample from (2010,2011,2012,2013 and 2014) different time periods, representative 48 different areas of influenza A H1N1 (09pdm) positive isolates through using specific primers to amplify segments and measuring HA, NA, M, NP, NS, PA,PB1,PB2gene.(2) Statistical analysisMicrosoft office Excel sheet was used for data collation and arrangement, Predictive Analytics Software (PASW) version 18.0 for statistical data analysis, and forecasting module ILI week to analysed the number of cases.Influenza A/H1N1 flu vaccine strains were download from Gene bank database as a reference sequence using Lasergene 7.0 DNA star-package MegAlign, Edit Seq sequencing of PCR products to compared splicing and give a full-length sequence of each fragment; Molecular Evolutionary Genetics Analysis version (MEGA) 5.2.1 software was used for comparison between phylogenetic, gene and amino acid sequence analysis;monkey (http://www.datamonkey.org/dataupload.php) online software HA, NA gene selection pressure was used.Result(1) The positive influenza-like illness and the isolation rate:Time distribution, Five-years the cumulative reported 123,330 cases of ILI cases, Influenza virus isolation positive 14238,The positive rate was 11.54% isolated.2010-2012 ILI decreased, In 2013 the number of cases of influenza-like increase,And more than 2010 years 2014 influenza-like illness continues to rise, Reaches 2010 the highest value of 2014; Occupation, In kindergarten children and scattered children; Age distribution,0～age group the largest proportion, Fewer cases over 60 years old; Gender distribution, The number of cases of influenza-like men and women showed no significant difference; Regional distribution, ILI isolated southern Jiangsu and northern Jiangsu was higher than the Soviet Union.(2) Pathogen monitoring:In 2009 after an outbreak of influenza A/H1N1,2010 (H1N1) is still the after math, but then B and influenza A H1N1 seasonal H3 replaced a major influenza epidemic strains, since the spring of 2013, Influenza A H1N1 popular once again, and throughout the year to monitor the Influenza A H1N1, seasonal H3 become a major advantage in 2013 strain,2014 H1N1 influenza epidemic continues. (H1N1) and the influenza type B in high season mainly in winter and spring,H3 seasonal peak in summer period mainly; age distribution,5 to 24 age group infected with influenza B major, the remaining age groups the main influenza type A infection;Gender distribution,Men and women infected with various subtypes influenza difference was not statistically significant;Geographical distribution,Between the different regions of B-type influenza infection was no significant difference.(3) In 2010 the first week to the first 50 weeks in 2014 The number of cases of influenza-like modeled, predicted prediction model ARIMA (0,1,1).(4) The average total genetic nucleotide distance HA= NS1> PB2> M2= PA> NA> NS2= BI= NP> M1, the average total genetic amino acids from the HA> NA> M2= NS1> NS2> PB2> M1> PA> PB1> NP. Each sequence of nucleotides and amino acids increase over time, to a certain extent, Showing tendency to increase the genetic distance(5) The phylogenetic tree,2009-2010 (H1N1) strain and the prevalent strains early were highly homologous,during 2011 and 2012 H1N1 influenza rarely, since the start of 2013,majority of strains showed a larger variation, makes 2013 and 2014 strains obvious of earlier strains.(6) Analysis of key sites:HA protein, In addition to having a eight fixed-glycosylation sites,Part two new strains glycosylation sites, A135S occur in the receptor binding site 130 ring(1 Strain) mutation,220 ring occurred V220E (1 strain), D222N (1 Strain), D222G (3 Strains), Q223R (7 strains) G225A (1 strain) mutation, in a high mutation rate of 190 spiral, Occurred S190I (1 Strain), L191I (4 Strains), L191F (1 strain) mutation,13 mutation on the antigenic site (Ca 2 sites, Cbl site, Sa 5 sites, Sb 5sites), A strain occurred in HA proteolytic cleavage site of the non-basic amino acid variation;NA protein, a total of six fixed-glycosylation sites, in addition, some strains were increases glycosylation sites, and some strains appear as point mutation, resulting in the conversion of glycosylation sites or disappear. NA protease active site and the auxiliary sites were not around, the resistance sites;M, L26, V27, A30, G34 M,M2 series have not changed, and all strains have S31N mutation sites Changes;NS, the key site-specific mutation did not appear;NP, One strain has N202S change, one strain has K198R change;PA, separate strain occur mutation in the key site T173N (1), D189E (1), L226F (1), N228T (1), P224S (48), I690V (1), D111E (1);PB1, key sites appear no change;PB2, key sites appear no change;PB1-F2, strains in sites 12,58,88 appeared earlier termination codon, in addition, there are three strains appeared stop codon in the site of first nine termination codon.(7) The positive pressure sites pressure were observed in HAproteins site site 310 and NA proteins 4 byprssure sites analysis model. Conclusion(1) The two peaks in Jiangsu province are winter and early spring for influenza flu (December to January up to March) and summer are small peak observed in (July to September),2010-2012 influenza epidemic strains of type B and Seasonal H3N2 (season H3), The epidemic flu strains are seasonal A/H3N2 and type B. The main epidemic flu strains are seasonal A/H3N2 and A/H1N1(09pdm), since 2013, Recommendationson characteristics of influenza in Jiangsu province, take the appropriate measures of prevention and control;(2) It is better to use ARIMA model prediction, make prediction and early warning, Take timely preventive measures, in order to reducing unnecessary losses;(3)The influenza A/H1N1(09pdm)viruses had undergone molecular evolution to generate genetic diversity and emphasize the importance of reinforcing virus surveillance. |
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