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ObjectiveTo determine the prevalence of avian influenza viruses in the external environment of poultry in Anqing City， Anhui Province， and provide scientific evidence for prevention and control of animal-derived influenza in humans. MethodsA total of 28 farmers’ markets/farms in 10 counties （cities， districts） of Anqing City， Anhui Province， were selected as surveillance sites by simple random sampling strategy. Poultry faeces and other related samples were collected for 6 consecutive weeks. Real-time fluorescence quantitative PCR was used to examine the nucleic acids of influenza A virus. Subtypes H5， H7， and H9 of avian influenza virus were further tested in the positive samples. ResultsA total of 426 specimens were collected， among which 113 tested positive with a positive rate of 26.53%. Among the positive specimens， 104 were determined to be subtype H9， accounting for 92.04%. It did not significantly differ in the positive rate between the main and non-main urban areas （χ2<0.01， P>0.05） or among the specimens collected in different weeks （χ2=7.57， P>0.05）. However， it significantly differed in the positive rate among the specimens collected in the third week and other weeks （χ2=6.89， P<0.05）. Furthermore， among the different sampling sites， farms had the highest positive rate of 46.67%. Among the specimens from different sources， the surface-coated specimens from poultry cages had the highest positive rate of 34.78%. ConclusionAvian influenza viruses are prevalent in the external environment of poultry in Anqing City. It warrants strengthening the surveillance and risk assessment to reduce the virus transmission in the external environment and risk of human infection with animal-derived influenza.
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Objective:To analyze the genetic evolution and molecular characteristics of H5N8 avian influenza viruses (AIVs) isolated from the poultry in a live poultry market (LPM) in Urumqi, Xinjiang.Methods:Oropharyngeal and cloacal swabs of poultry were collected from a LPM in Urumqi in 2016. AIVs were isolated by inoculating swab samples into chicken embryos. Hemagglutination test and RT-PCR were used to identify the AIVs. The genes of isolated AIVs were amplified with the universal primers of AIV and whole-genome sequencing was also performed. Pairwise sequence alignment and analysis of phylogenetic and molecular characteristics were performed using BLAST, Clustal W, MEGA-X and DNAStar software.Results:Five H5N8 AIVs were isolated from poultry. These strains shared a nucleotide identity of 99.70%-100.00%, which indicated that they were from the same source, and were named XJ-H5N8/2016. Phylogenetic analysis based on hemagglutinin( HA), NS and PB2 genes showed that these isolates were clustered together with H5N8 AIVs isolated from the migratory swans in Hubei, Shanxi and Sanmenxia, and the ducks in India during 2016 to 2017. Moreover, they were also clustered together with H5N6 AIVs isolated from minks in China and the first case of human infection in Fujian. The phylogenetic tree of neuraminidase( NA) gene indicated the five isolates clustered together with H5N8 AIVs isolated from ducks in India in 2016, and the phylogenetic trees of PB1, MP, PA and NP genes showed that they were clustered together with H5N8 AIVs isolated from wild birds and poultry in Egypt, Cameroon, Uganda, Congo and other African countries in 2017. The HA cleavage sites of XJ-H5N8/2016 contained five consecutive basic amino acids, indicating high pathogenicity. Multiple mutations in the genes of XJ-H5N8/2016 could enhance its virulence and pathogenicity to mammals. Conclusions:The five strains of H5N8 AIVs isolated from the LPM were highly pathogenic and closely related to the H5N8 AIVs isolated from migratory birds and poultry in Hubei, Shanxi, Sanmenxia area, Africa and India during 2016 to 2017. Meanwhile, some of the viral genes were also closely related to the H5N6 AIVs isolated from the minks and human in China. Multiple mutations could increase the virulence and pathogenicity of AIVs to mammals, which could pose a potential threat to public health.
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The conserved hemagglutinin (HA) stem region of avian influenza virus (AIV) is an important target for designing broad-spectrum vaccines, therapeutic antibodies and diagnostic reagents. Previously, we obtained a monoclonal antibody (mAb) (5D3-1B5) which was reactive with the HA stem epitope (aa 428-452) of H7N9 subtype AIV. To systematically characterize the mAb, we determined the antibody titers, including the HA-binding IgG, hemagglutination-inhibition (HI) and virus neutralizing (VN) titers. In addition, the antigenic epitope recognized by the antibody as well as the sequence and structure of the antibody variable region (VR) were also determined. Moreover, we evaluated the cross-reactivity of the antibody with influenza virus strains of different subtypes. The results showed that the 5D3-1B5 antibody had undetectable HI and VN activities against H7N9 virus, whereas it exhibited strong reactivity with the HA protein. Using the peptide-based enzyme-linked immunosorbent assay and biopanning with a phage-displayed random peptide library, a motif with the core sequence (431W-433Y-437L) in the C-helix domain in the HA stem was identified as the epitope recognized by 5D3-1B5. Moreover, the mAb failed to react with the mutant H7N9 virus which contains mutations in the epitope. The VR of the antibody was sequenced and the complementarity determining regions in the VR of the light and heavy chains were determined. Structural modeling and molecular docking analysis of the VR verified specific binding between the antibody and the C-helix domain of the HA stem. Notably, 5D3-1B5 showed a broad cross-reactivity with influenza virus strains of different subtypes belonging to groups 1 and 2. In conclusion, 5D3-1B5 antibody is a promising candidate in terms of the development of broad-spectrum virus diagnostic reagents and therapeutic antibodies. Our findings also provided new information for understanding the epitope characteristics of the HA protein of H7N9 subtype AIV.
Subject(s)
Animals , Antibodies, Monoclonal , Antibodies, Viral , Hemagglutinin Glycoproteins, Influenza Virus/genetics , Hemagglutinins , Influenza A Virus, H7N9 Subtype , Influenza in Birds , Molecular Docking SimulationABSTRACT
Compound houttuynia mixture belongs to OTC class A medicine, which is made from Houttuynia cordata, Scutellaria baicalensis, Radix Isatidis, Forsythia, and Lonicera. As a kind of compound preparation of traditional Chinese medicine, houttuynia cordata mixture has extensive pharmacological effects, for example, clearing away heat and detoxifying, thus it is used for the sore throat, acute pharyngitis, and tonsillitis with wind-heat syndrome. In this study, the antiviral activity against influenza viruses and the primary mechanism of compound houttuynia mixture was evaluated. The antiviral effect of compound houttuynia mixture was determined by cytopathic effects (CPE), Western blot, quantitive reverse transcription PCR (qRT-PCR), and virus titer assays. The effect of houttuynia mixture on the replication cycle of influenza virus was evaluated by time-of-addition assay. In conclusion, the results showed that the compound houttuynia mixture had a broad-spectrum effect against influenza virus, including the international common influenza virus strains, the drug-resistant strains and the highly pathogenic avian influenza viruses H5N1 and H7N9. It mainly impairs the early stage of the viral replication.
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@#Objective To analyze genetic characteristics of hemagglutinin( HA) gene of H9N2 avian influenza viruses( AIVs) circulating in Anhui Province from 2013 to 2018． Methods All H9N2 positive samples tested by real－time polymerase chain reaction( PCＲ) were inoculated into specific patho- gen free ( SPF) chicken eggs for isolation and purification． Viral ＲNA was reversely transcribed into cD- NA and then amplified with gene specific primers． PCＲ products were sequenced and the gene sequences were analyzed using molecular and bioinformatics software． The DATAMONKEY online server was conducted to analyze selection pressure，and protein structure homology modelling was computed by the SWISS－MODEL server． Ｒesults 33 H9N2 AIVs isolated from live poultry markets belonged to h9．4．2．5 in the phylogenetic tree． The receptor binding sites of HA gene at 183，226 and 227 position were mutated into N，L and M，respectively． Meanwhile 189 and 190 sites presented with genetic polymorphism． Since 2015，all H9N2 viruses in this study carried 6 potential N－linked glycosylation sites． It was found that po- sition 160 of HA gene was subjected greater positive selection pressure，presented 7 spatial conformations at least． Conclusions The H9N2 viruses isolated from live poultry markets in Anhui Province possess the molecular characteristics of infecting mammals and the ability of antigenic drift，so we need to pay more attention to the genetic characteristics of the viruses．
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Background & objectives: Avian influenza (AI) viruses have been a major cause of public health concern. Wild migratory birds and contaminated environmental sources such as waterbodies soiled with bird droppings play a significant role in the transmission of AI viruses. The objective of the present study was to develop a sensitive and user-friendly method for the concentration and detection of AI viruses from environmental water sources. Methods: Municipal potable water, surface water from reservoirs and sea were spiked with low pathogenic AI viruses. To concentrate the viruses by precipitation, a combination of potassium aluminium sulphate with milk powder was used. Real-time reverse transcription-polymerase chain reaction was performed for virus detection, and the results were compared with a virus concentration method using erythrocytes. Drinking water specimens from poultry markets were also tested for the presence of AI viruses. Results: A minimum of 101.0 EID50(50% egg infectious dose)/ml spiked H5N1 and 101.7 EID50/ml spiked H9N2 viruses were detected from spiked potable water; 101.0 and 102.0 EID50/ml spiked H5N1 virus was detected from surface water and seawater samples, respectively. The present method was more sensitive than the erythrocyte-binding method as approximately 10-fold higher infectious virus titres were obtained. AI H9N2 viruses were detected and isolated from water from local poultry markets, using this method. Interpretation & conclusions: Viability and recovery of the spiked viruses were not affected by precipitation. The present method may be suitable for the detection of AI viruses from different environmental water sources and can also be applied during outbreak investigations.
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Objective To explore the source of human infection H9N2 avian influenza virus (AIV). Methods Environmental AIV nucleic acid monitoring was conducted for live poultry markets in Changsha city from 2014 to 2015, and data of human infection H9N2 subtype AIV cases worldwide were collected. Phylogenetic trees of hemagglutinin(HA), neuraminidase(NA)and non-structural protein(NS)genes from human infection H9N2 subtype AIV, the live poultry markets environmental H9N2 subtype AIV and partial avian H9N2 subtype AIV were constructed using the MEGA 6.06 software, respectively. Results In 2014-2015, H9 subtype AIV had the highest nucleic acid positive rate (44.76%) in the live poultry markets environment of Changsha city, and the pollution was serious. A total of 27 cases of human infection with H9N2 subtype AIV had been reported worldwide, and most of these patients recovered after treatments.Epidemiological survey showed that 59.26% (16/27) of cases had a clear history of exposure to poultry or live poultry markets. The phylogenetic trees of HA, NA and NS genes showed that the human infection H9N2 subtype AIV isolates isolated from Hunan and Guangdong were closely related to the H9N2 subtype AIV isolated from the live poultry markets environment in Hunan and Guangdong provinces from 2013 to 2016. The nucleotide similarity was as high as 97%-99%. Conclusion Live poultry market is one of the sources of human infection with H9N2 influenza virus.
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Objective To explore the predictive value of neutrophil-to-lymphocyte ratio on the prognosis of H7N9 avian influenza.Methods A retrospective analysis was conducted on 28 H7N9 avian influenza patients (treatment group) at the First Affiliated Hospital of Soochow University from April 2013 to January 2016.Thirty healthy physical examiners in the same period were enrolled as the healthy control group.The 28 patients were followed up for half a year and divided into the improvement group (18 cases) and the death group (10 cases) according to the clinical prognosis.Inflammatory indicators including white blood cells (WBC),neutrophil (N),lymphocyte (L),monocytes (M),platelet (PLT),creatine kinase (CK),lactate dehydrogenase (LDH),high sensitive C reactive protein were collected at day 1,day 3 and week 1 of admission.Calculation of neutrophil-to-lymphocyte ratio (NLR),platelet-to-lymphocyte ratio (PLR),lymphocyte-to-monocyte ratio (LMR),△NLR3 (day 3 of admission NLR-on day 1 of admission NLR),△NLR7 (week 1 of admission NLR-day 3 of admission NLR) and so on calculating △PLR3,△PLR7,△LMR3,△LMR7.Differences of the above indicators between the improvement group and death group were compared.The measurement data with normal distribution were tested by t-test of two independent samples,and the count data with non-normal distribution were tested by Mann-Whitney U-test.Univariate and multivariate logistic regression analysis to explore the prognostic factors and the working characteristic curve of subjects was used to evaluate the predictive value of inflammatory response indexes for H7N9 avian influenza death.Results In the treatment group,the baseline WBC,L,N,PLT,the proportion of lymphocytes,neutrophils,monocytes,and NLR,PLR,and LMR were all statistically different compared with the healthy control group (all P ＜0.01).After treatment,day 3 NLR,△NLR3 in improvement group were both significantly decreased to 10.93 (15.71)and0.87 (-15.63),respectively when compared with death group (17.62[23.63] and 7.42[22.68],respectively) (Z =-2.16 and-2.014,respectively,both P＜0.05).Day 7 NLR,△NLR7 in improved group were 6.51 (13.23) and-0.37 (-12.38),respectively,which were both lower than those of death group (27.90 [25.64] and 11.54 [-26.22]) with statistically significant differences (Z =-2.444 and -2.111,respectively,both P ＜ 0.05).Multivariate logistic regression analysis indicates that △NLR3 is the main factor that affects the prognosis of the H7N9 infection (odds ratio [OR] =1.153,95％ confidence interval [CI]:1.052-1.263,P =0.002).Reciver operating characteristic curve analysis showed that the area under the curve was 0.733 (95 ％ CI:0.532-0.935,P =0.044).Based on the principle of Youden index,the cutoff value of △NLR3 to predict the death risk of H7N9 avian influenza was 5.453 with sensitivity of 0.700 and the specificity of 0.722.The mortality was higher when △NLR3 was higher than 5.453.Conclusions Dynamic monitoring NLR,especially △NLR3 may reflect the condition and prognosis of H7N9 infection,which is an independent predictor of death.
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This study examined the disinfection conditions (exposure time, 0–30 min; exposure temperature, 4℃–65℃) of hypochlorous acid water (HOCl) in automobile disinfection equipment. The study tested poliovirus type 1 (PV1), low pathogenic avian influenza virus (AIV, H9N2), and foot and mouth disease virus (FMDV, O type). As a result, the PV1 and FMD viruses were inactivated easily (virus titer 4 log value) by HOCl (> 100 ppm) but the AIV required higher exposure temperatures (> 55℃). In conclusion, the exposure temperature and time are important factors in deactivating AIV and FMDV.
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Animals , Automobiles , Disinfection , Foot-and-Mouth Disease Virus , Foot-and-Mouth Disease , Hypochlorous Acid , Influenza in Birds , Poliovirus , WaterABSTRACT
To establish appropriate conditions for a disinfectant efficacy test at subzero temperatures, this study examined mixtures of frozen foot-and-mouth disease virus or avian influenza virus solutions and disinfectant diluents at −5℃ and monitored temperature and freezing status of an anti-freezing diluent (AFD, 15% ethanol + 30% propylene glycol + 55% distilled water) over time at various subzero temperatures. Viral solutions and disinfectant diluents froze before the mixtures reached −5℃, whereas the AFD was not frozen at −30℃. The times taken for the AFD to reach −10, −20, −30, and −40℃ from room temperature were 36, 39, 45, and 48 min, respectively.
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Animals , Ethanol , Foot-and-Mouth Disease Virus , Freezing , Influenza in Birds , Propylene GlycolABSTRACT
The annual seasonal epidemic of influenza caused serious disease burden around the world,and serious social panic and economic losses.Due to the high variability and uncertainty of influenza virus,prevention and control of influenza faces many challenges.Surveillance is a key strategy to prevent and control influenza,and influenza is the first infectious disease to be monitored globally.More than 60 years,influenza surveillance programs in China has made great contributions to the prevention and control of influenza in China and the world.Especially in the past 10 years,the influenza surveillance network has developed rapidly,the scale has been expanded significantly,the monitoring content and scope have been continuously improved,and the monitoring quality has been rapidly improved.The China Influenza Surveillance Network is one of the early detection systems for emerging infectious diseases in China and the world.It helps to improve the capacity of public health system in prevention and control and early warning of emerging infectious diseases.
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In 2013, two episodes of influenza emerged in China and caused worldwide concern. A new H7N9 avian influenza virus (AIV) first appeared in China on February 19, 2013. By August 31, 2013, the virus had spread to ten provinces and two metropolitan cities. Of 134 patients with H7N9 influenza, 45 died. From then on, epidemics emerged sporadically in China and resulted in several victims. On November 30, 2013, a 73-year-old woman presented with an influenza-like illness. She developed multiple organ failure and died 9 d after the onset of disease. A novel reassortant AIV, H10N8, was isolated from a tracheal aspirate specimen that was obtained from the patient 7 d after onset. This case was the first human case of influenza A subtype H10N8. On 4 February, 2014, another death due to H10N8 avian influenza was reported in Jiangxi Province, China.
Subject(s)
Aged , Female , Humans , China , Epidemiology , Influenza A Virus, H10N8 Subtype , Classification , Influenza A Virus, H7N9 Subtype , Classification , Influenza A Virus, H9N2 Subtype , Classification , Influenza, Human , Epidemiology , Virology , Phylogeny , Reassortant Viruses , ClassificationABSTRACT
Objective@#To analyze the distribution and the molecular biological characteristics of variant subtypes (H5, H7 and H9) of avian influenza virus (AIV) in the live poultry related external environment of Quanzhou form 2014 to 2017, and provide regional references for the prevention, control and early-warning of human infections.@*Methods@#Samples from monitoring sites of live poultry were collected in Quanzhou from 2014 to 2017. Influenza A and variant subtypes of AIV (H5, H7 and H9) were detected by real time RT-PCR, and the detection results were further analyzed statistically. Furthermore, the HA and NA genes of four representative H7N9 strains were sequenced, and the results were further analyzed with DNAstar and MEGA7.0.@*Results@#Among the samples from external environment, the positive rate of nucleic acid of influenza A was 29.04% (377/1 289), of which the positive rates of H5, H7 and H9 subtypes were 3.80%, 13.34% and 12.02%, respectively. The positive rate of H7N9 was higher than those of the other subtypes in all monitored years, of which the highest rate was found in 2017 (21.88%). As to the different types of samples, chopping board possessed the highest positive rate of influenza A (65.4%), followed by waste water (59.3%) and drinking water for the poultry (29.6%). Among the different monitoring sites, the positive rate of poultry farm is 6.94%, far lower than that in the open air (61.7%) and the live poultry trading market (52.8%). Sequencing of the HA and NA genes of four strains of H7N9 showed that the strains from external environment and the strains from H7N9 patients belonged to Pearl River Delta and Yangtze River Delta lineage, respectively. The cleavage sites of HA proteins of these four strains were all PKGR/G without highly pathogenic mutation. Meanwhile, they were low pathogenic H7N9 without oseltamivir resistant mutation (R292 K in NA), while they all possessed the E627 K mutation in the PB2 genes associated with virulence.@*Conclusions@#H7N9 AIV existed in the live poultry related external environment of Quanzhou, especially the farmers’ and the live poultry trading market, so that more persistent surveillance could be needed in the future.
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Objective The objective of our study was to conduct meta-analyses that examined the association between H7N9-infected case-fatality risk (CFR) and underlying medical conditions (UMCs) by adjusting some potential factors variables. Methods The articles of observational studies and randomized controlled clinical trials (RCT) on the association between UMCs and the CFR of H7N9-infected patients were collected and selected according to inclusion and exclusion criteria. Meta-analysis was performed to calculate odds ratio (OR) or adjusted OR (AOR) and 95％ confidence interval (CI) to assess the association between H7N9-infected CFR and UMCs. Results Among 1934 screened articles, we identified 14 articles reporting the CFR of H7N9-infected patients based on UMCs data. The pooled summary estimates from these studies indicated that UMCs significantly increased the risk of death in H7N9 patients (OR=2.20, 95％CI: 1.76-2.76) . Subgroup analyses showed chronic respiratory diseases (CRD, OR=4.43, 95％CI: 1.73-11.31), immuno-suppressive disorders (ISD, OR=4.65, 95％ CI:1.48-44.70), and two UMCs and above (OR=2.13, 95％ CI: 1.26-5.97) were significantly associated with H7N9-infected CFR; while 60 years old and above (AOR=4.83, 95％CI: 1.29-18.09), male (AOR=2.35, 95％CI: 1.03-5.39), time intervals to oseltamivir treatment (over 5 days) (AOR=5.74, 95％ CI: 1.15-28.66) and hospitalization (over 8 days) (AOR=2.72, 95％CI: 1.20-6.15), and initially bilateral lungs infection (AOR=7.95, 95％CI: 1.56-40.41) of UMCs patients who died from H7N9 infection are much greater compared with non-UMCs. Stratification analyses confirmed statistically significant increasing effects of CFR were observed in 60 years old and above (AOR=2.20, 95％ CI: 1.12-4.30) , time intervals to oseltamivir treatment (over 5 days) (AOR=3.19, 95％CI: 1.56-6.53), and initially bilateral lungs infection (AOR=3.48, 95％CI: 1.74-6.95) compared with 0-59 years old, time intervals to oseltamivir treatment (5 days and below), and initially single lung infection respectively in H7N9-infected patients with UMCs. Conclusions We find that only CRD, ISD, and two UMCs and above are associated with increased risk of death in H7N9-infected patients. We also suggest that a high CFR is associated with 60 years old and above, delayed antiviral treatment, and initially bilateral lungs infection in H7N9-infected patients with UMCs.
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Short-term closing live poultry markets have been frequently adopted to control H7N9 epidemic.To evaluate the effect of short-term closing live poultry markets,we analyzed the data of environment surveillance of H7 by RT-PCR,and the human H7N9 cases in Zhongshan City from Feb 2014 to May 2017.RRx =The positive rate during the x-th week after closing / the positive rate of the week before closing days * 100％.Three rounds of short-term closing live poultry markets were administered.Round one:from Feb 10 to 23,2014,the neighboring cities didn't synchronize.The H7 positive rate increased since the trade recovered,and RR1 =0.40 (95％CI:0.28-0.59),RR3 =0.63 (95％CI:0.32-1.24),RR4 =0.83 (95％CI:0.48 -1.46).Two human cases were reported in May,2014.Round two:from Feb 19 to 28,2015,the neighboring cities synchronized as the province policy.The H7 positive rate maintained a level lower than 10％ since the trade recovered,and RR1 =0.15 (95％CI:0.07-0.34),RR2=0.21 (95％CI:0.10-0.41),RR3 =0.03 (95％CI:0.00-0.18),RR4 =0.10 (95％CI:0.04-0.27).No more human cases reported in that epidemic season.Round three:from Jan 8 to 21,2017,the neighboring cities didn't synchronize with Zhongshan City.The H7 positive rate had increased since the trade recovered,and RR1 =0.25 (95 ％ CI:0.09-0.68),RR3 =0.37 (95％CI:0.14-1.00),RR4 =1.07 (95％CI:0.54-2.11).Two human cases were reported in Feb,2017.Results indicated that,if the policy of closing live poultry markets was administered in single city,the environment pollution rate would rise shortly and the risk of human infection would increase once the trade recovered.However,if it was synchronously administered in all the cities in one region,the environment pollution rate could maintain at a low level and the risk of human infection would reduce enormously.
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Objective To investigate the molecular characteristics of H5 subtype avian influenza viruses (AIV) in Weining, Guizhou Province. Methods Nine representative strains were randomly select-ed from H5 subtype AIV that were identified by real-time PCR in Weining, Guizhou Province from 2015 to 2017. Nucleic acid was extracted from each sample and hemagglutinin (HA) genes were amplified and then sequenced. Homology, genetic evolution and the sites related to pathogenicity, receptor binding regions as well as potential glycosylation of H5 AIV were analyzed by bioinformation software. Results Homology analysis revealed that there was 96. 1%-99. 9% and 95. 7%-100% similarity among the nine strains in nu-cleotide and amino acid of HA gene, respectively. These strains belonged to two branches, H5-1 and H5-2. The cleavage site motifs were PLREKRRKR↓GLF for five strains in H5-1 branch and PQRERRRKR↓GLF for four strains in H5-2 branch, which made them high pathogenic. QSG and QRG at the key receptor bind-ing sites were found in H5-1 and H5-2 branch strains, respectively. They were responsible for receptor bind-ing specificity of AIV. Mutations of 138Q, 139G and 53K were all detected in the nine strains. 129K, 189T, 140K and 282V mutations were discovered in the five strains of H5-1 branch, while 189N, 140M and 282I mutations were found in the four strains of H5-2 branch. Results of the glycosylation motif analysis showed that six sites were conservative, but there was an addition of 124NHT site in two strains of H5-2 branch isolated in 2017. Conclusion Two high pathogenic H5 subtypes of AIV could be epidemic in Wein-ing, Guizhou Province during 2015 to 2017. Although H5 subtype AIV did not possess specific receptor binding regions like human influenza viruses, they were in continuous variation with an increase in glycosyla-tion motifs, which might enhance their virulence and pathogenicity to human beings. Hence, surveillance and study on the molecular properties of H5 subtype AIV should be strengthened.
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The annual seasonal epidemic of influenza caused serious disease burden around the world,and serious social panic and economic losses.Due to the high variability and uncertainty of influenza virus,prevention and control of influenza faces many challenges.Surveillance is a key strategy to prevent and control influenza,and influenza is the first infectious disease to be monitored globally.More than 60 years,influenza surveillance programs in China has made great contributions to the prevention and control of influenza in China and the world.Especially in the past 10 years,the influenza surveillance network has developed rapidly,the scale has been expanded significantly,the monitoring content and scope have been continuously improved,and the monitoring quality has been rapidly improved.The China Influenza Surveillance Network is one of the early detection systems for emerging infectious diseases in China and the world.It helps to improve the capacity of public health system in prevention and control and early warning of emerging infectious diseases.
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ABSTRACT The red-tailed Amazon parrot (Amazona brasiliensis) is a threatened species of psittacine bird that inhabit coastal regions of Brazil. In view of the threat of this species, the aim of this study was to perform a health evaluation in wild nestlings in Rasa Island, determining the prevalence of enterobacteria and infectious agents according to type of nest. Blood samples were collected from 64 birds and evaluated for antibodies of Chlamydia psittaci by commercial dot-blot ELISA. Cloacal and oropharyngeal swabs samples were collected from 23 birds from artificial wooden nests, 15 birds from PVC nests and 2 birds from natural nests for microbiological analysis. Swab samples were collected from 58 parrots for C. psittaci detection by PCR and from 50 nestlings for Avian Influenza, Newcastle Disease and West Nile viruses' detection analysis by real-time RT-PCR. Ten bacterial genera and 17 species were identified, and the most prevalent were Escherichia coli and Klebsiella oxytoca. There was no influence of the type of nest in the nestlings' microbiota. All samples tested by ELISA and PCR were negative. There is currently insufficient information available about the health of A. brasiliensis and data of this study provide a reference point for future evaluations and aid in conservation plans.
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Animals , Bacteria/isolation & purification , Bacterial Infections/veterinary , Viruses/isolation & purification , Bird Diseases/microbiology , Bird Diseases/virology , Virus Diseases/veterinary , Amazona/microbiology , Amazona/virology , Bacteria/classification , Bacteria/genetics , Bacterial Infections/microbiology , Viruses/classification , Viruses/genetics , Brazil , Virus Diseases/virology , Endangered Species , Islands , Animals, Wild/microbiology , Animals, Wild/virologyABSTRACT
Objective To investigate the distribution of avian influenza A viruses in external environment in Urumqi City in order to provide reference for the prevention and control of human infection with avian influenza virus in Urumqi City.Methods Environmental specimens were collected from 2013 to 2015 to detect avian influenza A virus nucleic acid with real-time fluorescent PCR.The positive specimens were further analyzed to identify the subtypes of avian influenza A viruses.Results A total of 1 043 environmental specimens were collected and tested.Among them,123 specimens were positive for avian influenza A virus nucleic acid with an overall positive rate of 11.79%.H9 was the predominant subtype,accounting for 7.77% of all specimens.Quarterly detection rates of avian influenza A virus in the three years peaked in different quarters of the year.Of all surveillance sites,live poultry markets in urban and rural areas had the highest positive rate (14.23%).Specimens collected from poultry drinking water (18.44%) and other specimens (19.44%) were highly positive for avian influenza A virus.Conclusion Avian influenza A viruses,especially the subtypes of H5,H7 and H9,exist in live poultry markets in Urumqi City.It is necessary to conduct surveillance and health education among people exposed to poultry in live poultry markets.
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Objective: To investigate serologically the presence of avian influenza virus (AIV) in backyard chickens from Mandlhakazi district, Southern Mozambique. Methods: A total of 439 sera samples from unvaccinated and apparently healthy backyard chickens from 4 villages (Chidenguele, Macuacua, Chizavane, and Nwadja-hane) were tested for the presence of AIV antibodies through commercial enzyme-linked immunoabsorbent assay (ELISA) kit used according to manufacturer instructions. Results: Anti-AIV antibodies were detected in all villages surveyed. The overall sero-prevalence obtained was 32.6％ (95％ CI 28.2％–37.0％). The highest prevalence of 51.3％ (95％ CI 42.3％–60.2％) was recorded in Macuacua village, while the lowest prevalence of 13.0％(95％CI 6.2％–19.9％) was found in Chizavane village. The results of logistic regression analyses suggested that chicken being located in Chizavane and Macuacua villages were more unlikely for getting the virus exposure (P<0.05). Conclusions: Our findings suggested that AIV is widespread within backyard chickens in the studied villages. Further research is needed to identify the circulating virus ge-notypes and determine the potential role of backyard chickens in the zoonotic trans-mission of AIV in Mozambique.