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>

An overview of surveillance of avian influenza viruses in wild birds / 病毒学报

Wild birds (mainly Anseriformes and Charadriiformes) are recognized as the natural reservoir of avian influenza viruses (AIVs). The long-term surveillance of AIVs in wild birds has been conducted in North America and Europe since 1970s. More and more surveillance data revealed that all the HA and NA subtypes of AIVs were identified in the wild ducks, shorebirds, and gulls, and the AIVs circulating in wild birds were implicated in the outbreaks of AIVs in poultry and humans. Therefore, the AIVs in wild birds pose huge threat to poultry industry and human health. To gain a better understanding of the ecology and epidemiology of AIVs in wild birds, we summarize the transmission of AIVs between wild birds, poultry, and humans, the main results of surveillance of AIVs in wild birds worldwide and methods for surveillance, and the types of samples and detection methods for AIVs in wild birds, which would be vital for the effective control of avian influenza and response to possible influenza pandemic.

A novel reassortant H3N8 influenza virus isolated from drinking water for duck in a domestic duck farm in Poyang Lake area / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To conduct a full genome sequence analysis for genetic characterization of an H3N8 influenza virus isolated from drinking water of a domestic duck farm in Poyang Lake area in 2011.</p><p><b>METHODS</b>The virus was cultivated by specific pathogen free (SPF) chicken embryo eggs and was subtyped into hemagglutinin (HA) and neuraminidase (NA) by real-time PCR method. Eight gene segments were sequenced and phylogenetic analysis was conducted.</p><p><b>RESULTS</b>The NA gene of this virus belongs to North American lineage; other seven genes belong to Eurasian lineage. Compared with the viruses containing NA gene, the PB2 and PB1 gene came from different clades. And this indicates that the virus was a novel reassortant genotype. The HA receptor binding preference was avian-like and the cleavage site sequence showed a low pathogenic feature. There was no drug resistance mutation of M2 protein. The mutations of Asn30Asp, and Thr215Ala of the M1 protein implied the potential of pathogenicity increase in mice.</p><p><b>CONCLUSION</b>The finding of novel genotype of H3N8 virus in drinking water in this duck farm near Poyang Lake highlighted the importance of strengthening the surveillance of avian influenza in this region, which could contribute to pinpointing the influenza ecological relations among avian, swine, and human.</p>

Epidemiological characteristics on the clustering nature of pandemic (H1N1) 2009 in China / 中华流行病学杂志

Objective To study the epidemiological characteristics on the clustering nature of pandemic (H1N1) 2009 in China.Methods Time and place distribution of pandemic (H1N1) 2009on the nature of clustering through data from Public Health Emergency Management Information System were described.Results As of August 10,2010,2773 pandemic (H1N1) 2009 clusters,a total of 77363 cases (including 20 deaths) were reported in the mainland of China.The most reported number of clusters was from schools and kindergartens with the total number of 2498 (accounted for 90.08％ of the total number).Middle schools appeared the have the most clusters (1223,accounting for 48.96％ ).The number of clusters reported in the southern provinces (cities) accounted for 77.03％ of the total,and was more than that in the northern provinces (cities).Two reported peaks in the southern provinces (cities) were in June and November,2009,respectively.There was only one reported peakin the northern provinces in September,2009.Conclusion Time and place distribution characteristics on the clusters of pandemic (H1N1) 2009 were similar to the seasonal influenza,but the beginning of winter peak was much earlier and intensity of reporting was much higher on the clusters of pandemic (H1N1 ) 2009 than that of seasonal influenza.

Risk factors for influenza A (H1N1) -associated pneumonia on hospitalized people less than 18years old in China, 2009-2010 / 中华流行病学杂志

Objective To describe the epidemiological and clinical features of hospitalized people less than 18 years old with influenza A (H1N1)-associated pneumonia and associated risk factors.Methods Through Chinese Reporting System of Influenza A (H 1 N1 ),children aged under 18 years who were hospitalized with laboratory confirmed influenza A (H1N1),case report forms and related information on pneumonia were collected between 1 September 2009 and 4 July 2010.Epidemiological and clinical characteristics including demographics,underlying chronic diseases,treatment,complications and clinical outcome etc.were described.Hospitalized children with pneumonia were compared with those without the above mentioned features,through the univariate and multivariate analysis.Results There were 4240 influenza A (H1N1)-associated hospitalized children with case report forms identified.Of the 4107 influenza A (H1N1) -associated hospitalized children with related information on pneumonia shown in the case report forms,2289 (55.7％) of them had pneumonia.Hospitalized children with influenza A (H1N 1 ) -associated pneumonia had a younger median age (4.9year old),when compared with those without pneumonia (13.1 year old,P＜ 0.0001 ).When compared with the hospitalized children without pneumonia,those hospitalized children with pneumonia were more likely to require intensive care unit care,using mechanical ventilation epuipmentto develop ARDS,respiratory failure or leading to death.Data from multivariate analysis showed that children aged ＜6months(OR=7.08,95％CI:4.15-12.06) between 6 and 23 months(aOR=8.26,95％CI:6.10-11.20) or between 2 to 4 year old (aOR=9.53,95％CI:7.39-12.29) were more likely to develop pneumonia than children aged 5 to 17.Factors as having asthma (OR=12.19,95％ CI:5.18-28.72),cardiovascular disease (OR=5.19,95％ CI:1.94-13.90),chronic renal diseases (OR=2.14,95％ CI:1.02-4.53),chronic hepatic diseases ( OR =5.26,95％ CI:1.40-19.81 ) and allergy (OR=2.54,95％ CI:1.64-3.93 )were significantly associated with influenza A (H1N1) -associated pneumonia.Risk of complication with pneumonia had an increase when oseltamivir treatment was initiated ＞2 days after the onset of illness.Conclusion Pneumonia was a common complication among children hospitalized with influenza A (H1N1).Hospitalized children with influenza A (H1N1)-associated pneumonia were more likely to develop either severe clinical courses or outcomes than those without pneumonia.

Inhibitory responses of parabrachial neurons evoked by taste stimuli in rat / 生理学报

In the present study, the responses of inhibitory gustatory neurons in the parabrachial nucleus (PBN) to four basic taste stimuli NaCl, HCl, quinine HCl (QHCl) and sucrose were examined using single-unit recording technique in anesthetized rats. A total of 18 inhibitory taste neurons in the PBN were obtained. Spontaneous firing rates of these inhibitory neurons were 0.2-5.5 Hz with mean firing rate of (2.15+/-0.31) Hz. Most of the neurons responded to more than one of the basic taste qualities. The inhibitory responses to taste occurred quickly and lasted 5-80 s in different PBN neurons. According to the responsive characteristics to the four basic taste stimuli, the neurons could be classified as NaCl-best (n=8), HCl-best (n=3), QHCl-best (n=3), and sucrose-best (n=4). The breadth of tuning of NaCl-best neurons was the highest (0.945). Inhibitory responsive neurons had feeble discrimination among sapid stimuli or aversive stimuli. These results suggest that there exist inhibitory taste neurons in the PBN. These neurons may play some useful roles in precise transmission of taste information and the taste coding for hedonic and aversive tastes.