Phylogenetic and Molecular Analysis of an H7N7 Avian Influenza Virus Isolated in East Dongting Lake in 2012 / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>In March 2012, an H7N7 subtype avian influenza virus (AIV) named A/wild goose/Dongting/PC0360/2012 (H7N7) (DT/PC0360) was recovered from a wild goose in East Dongting Lake. We performed whole-genome sequencing of the isolate, and analyzed the phylogenetic and molecular characterization.</p><p><b>METHODS</b>RNA was extracted from environment samples (including fecal samples from wild bird or domestic ducks, and water samples) for detecting the presence of Influenza A Virus targeting Matrix gene, using realtime RT-PCR assay. The positive samples were performed virus isolation with embryonated eggs. The subtype of the isolates were identified by RT-PCR assay with the H1-H16 and N1-N9 primer set. The whole-genome sequencing of isolates were performed. Phylogenetic and molecular characterizations of the eight genes of the isolates were analyzed.</p><p><b>RESULTS</b>Our results suggested that all the eight gene segments of DT/PC0360 belonged to the Eurasian gene pool, and the HA gene were belonged to distinct sublineage with H7N9 AIV which caused outbreaks in Mainland China in 2013. The hemagglutinin cleavage site of HA of DT/PC0360 showed characterization of low pathogenic avian influenza virus.</p><p><b>CONCLUSION</b>Strengthening the surveillance of AIVs of wild waterfowl and poultry in this region is vital for our knowledge of the ecology and mechanism of transmission to prevent an influenza pandemic.</p>

Analysis of genetic features of influenza B virus in Hunan province from 2007 to 2010 / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the gene variations of influenza B virus isolated in Hunan province from 2007 to 2010.</p><p><b>METHODS</b>A total of 42 strains of influenza B virus,which were isolated in the Influenza Surveillance Network Laboratories in Hunan province between year 2007 and 2010, were selected for the study. The hemagglutinin 1 (HA1) and neuraminidase (NA) genes of the selected strains were amplified by RT-PCR, and the sequence of the purified product were detected and homologically compared with the sequence of influenza vaccine strains isolated from Northern Hemisphere by WHO during the same period. In addition, the phylogenetic trees were constructed to characterize the molecular features.</p><p><b>RESULTS</b>In the Victoria branch of the HA1 gene phylogenetic tree, the strains isolated from year 2007 to 2009 were included in the V1 sub-branch, as well as the vaccine strain Malaysia/2506/2004; the strains isolated in year 2010 were involved in the V2 sub-branch, similar to the vaccine strains Brisbane/60/2008. In the Yamagata branch,the strains isolated in year 2007 were in the Y1 sub-branch,different from the strains isolated between year 2008 and 2010, which were in the Y2 sub-branch, instead. All virus in NA gene phylogenetic tree were included in the Yamagata branch, indicated their Yamagata origin. The genetic sequence analysis of the 7 strains isolated in year 2010 revealed that the viruses were classified as genotype 2 and genotype 15. The results of homological comparison between HA1 molecule and the influenza vaccine strains recommended by WHO were as below: Victoria lineage, 98.6% - 99.1% in 2007, 98.6% - 99.1% in 2008, 98.1% - 99.1% in 2009, and 97.6% - 99.1% in 2010; and Yamagata lineage, 97.9% - 98.5% in 2007, 97.9% - 98.5% in 2009 and 97.9% - 98.2% in 2010. The major mutations of the strains isolated in year 2007 were found in sites R48K, K88R, P108A, D197N and S230G. While the major mutations of the strains isolated between year 2009 and 2010 were sited in K88R, S150I, N166Y, D197N and S230G.</p><p><b>CONCLUSION</b>The prevalent influenza B virus isolated in Hunan province from 2007 to 2010 has mutated and evolved continuously.</p>

Serological survey of pandemic influenza A (H1N1) virus infection among population in Hunan Province / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To understand the infection condition and analytical methods of Influenza A (H1N1) virus in the population of Hunan Province during different periods.</p><p><b>METHODS</b>Quick surveys on the positive rate of Influenza A (H1N1) virus hemagglutination inhibition (HI) test have been conducted for 5 times successively from November 2009 to March 2010 in 14 medical and health institutions of Changsha city, whose results were then compared with those from the sampling surveys of whole Hunan province.</p><p><b>RESULTS</b>2131 subjects were involved in this study; the total population standardized rates of antibody positive investigated for 5 times were 9.32% , 14.62%, 31.08%, 28.43% and 22.80% respectively; the population of 6-17-years-old has the highest rate of antibody positive; only 9.84% of the antibody positive subjects attributed to vaccine inoculation; there was no significant difference in the standardized positive rates between the quick serological surveys and the corresponding sampling survey of Hunan province (P > 0.05).</p><p><b>CONCLUSION</b>The positive rate of A (H1N1) virus antibody reached the peak in late January 2010; quick investigations in small region could be used to evaluate the infection prevalence during pandemic of infectious diseases.</p>