Distribution of Avian Influenza A Viruses in Poultry-Related Environment and Its Association with Human Infection in Henan, 2016 to 2017

Objective To survey avian influenza A viruses(AIVs) in the environment and explore the reasons for the surge in human H7 N9 cases.Methods A total of 1,045 samples were collected from routine surveillance on poultry-related environments and 307 samples from human H7 N9 cases-exposed environments in Henan from 2016 to2017. The nucleic acids of influenza A(Flu A), H5, H7, and H9 subtypes were detected by real-time polymerase chain reaction.Results A total of 27 H7 N9 cases were confirmed in Henan from 2016 to 2017, 24 had a history of live poultry exposure, and 15 had H7 N9 virus detected in the related live poultry markets(LPMs). About 96%(264/275) Flu A positive-environmental samples were from LPMs. H9 was the main AIV subtype(10.05%) from routine surveillance sites with only 1 H7-positive sample, whereas 21.17% samples were H7-positive in H7 N9 cases-exposed environments. Samples from H7 N9 cases-exposed LPMs(47.56%)had much higher AIVs positive rates than those from routine surveillance sites(12.34%). The H7+H9 combination of mixed infection was 78.18%(43/55) of H7-positive samples and 41.34%(43/104) of H9-positive samples.Conclusion The contamination status of AIVs in poultry-related environments is closely associated with the incidence of human infection caused by AIVs. Therefore, systematic surveillance of AIVs in LPMs in China is essential for the detection of novel reassortant viruses and their potential for interspecies transmission.

Effects of closing and reopening live poultry markets on the epidemic of human infection with avian influenza A virus

Live poultry markets（LPMs） are crucial places for human infection of influenza A（H7N9 virus）.In Yangtze River Delta,LPMs were closed after the outbreak of human infection with avian influenza A（H7N9） virus,and then reopened when no case was found.Our purpose was to quantify the effect of LPMs＇ operations in this region on the transmission of influenza A（H7N9） virus.We obtained information about dates of symptom onset and locations for all human influenza A（H7N9） cases reported from Shanghai,Jiangsu and Zhejiang provinces by May 31,2014,and acquired dates of closures and reopening of LPMs from official media.A two-phase Bayesian model was fitted by Markov Chain Monte Carlo methods to process the spatial and temporal influence of human cases.A total of 235 cases of influenza A（H7N9） were confirmed in Shanghai,Jiangsu and Zhejiang by May 31,2014.Using these data,our analysis showed that,after LPM closures,the influenza A（H7N9） outbreak disappeared within two weeks in Shanghai,one week in Jiangsu,and one week in Zhejiang,respectively.Local authorities reopened LPMs when there was no outbreak of influenza A（H7N9）,which did not lead to reemergence of human influenza A（H7N9）.LPM closures were effective in controlling the H7N9 outbreak.Reopening of LPM in summer did not increase the risk of human infection with H7N9.Our findings showed that LPMs should be closed immediately in areas where the H7N9 virus is confirmed in LPM.When there is no outbreak of H7N9 virus,LPMs can be reopened to satisfy the Chinese traditional culture of buying live poultry.In the long term,local authorities should take a cautious attitude in permanent LPM closure.

Characterization of Highly Pathogenic Avian Influenza H5N1 Viruses Isolated from Domestic Poultry in China

The highly pathogenic avian influenza （HPAI） H5N1 virus has caused several outbreaks in domestic poultry. Despite great efforts to control the spread of this virus, it continues to evolve and poses a substantial threat to public health because of a high mortality rate. In this study, we sequenced whole genomes of eight H5N1 avian influenza viruses isolated from domestic poultry in eastern China and compared them with those of typical influenza virus strains. Phylogenetic analyses showed that all eight genomes belonged to clade 2.3.2.1 and clade 7.2, the two main circulating clades in China. Viruses that clustered in clade 2.3.2.1 shared a high degree of homology with H5N1 isolates located in eastern Asian. Isolates that clustered in clade 7.2 were found to circulate throughout China, with an east-to-west density gradient. Pathogenicity studies in mice showed that these isolates replicate in the lungs, and clade 2.3.2.1 viruses exhibit a notably higher degree of virulence compared to clade 7.2 viruses. Our results contribute to the elucidation of the biological characterization and pathogenicity of HPAI H5N1 viruses.

候鸟迁徙与禽流感(Avian Influenza,AI)传播

2003年以来,亚洲许多国家接连爆发了高致病性禽流感,对家禽养殖业已造成了巨大损失.通过分析禽流感和禽流感疫情暴发的季节性和区域性特点与鸟类迁徙特点的关系.我们认为鸟类迁徙在禽流感的传播中起重要作用.

Avian influenza and gut microbiome in poultry and humans:A“One Health”perspective

A gradual increase in avian influenza outbreaks has been found in recent years.It is highly possible to trigger the next human pandemic due to the characteristics of antigenic drift and antigenic shift in avian influenza virus(AIV).Although great improvements in understanding influenza viruses and the associated diseases have been unraveled,our knowledge of how these viruses impact the gut microbiome of both poultry and humans,as well as the underlying mechanisms,is still improving.The“One Health”approach shows better vitality in monitoring and mitigating the risk of avian influenza,which requires a multi-sectoral effort and highlights the interconnection of human health with environmental sustainability and animal health.Therefore,monitoring the gut microbiome may serve as a sentinel for protecting the common health of the environment,animals,and humans.This review summarizes the interactions between AIV infection and the gut microbiome of poultry and humans and their potential mechanisms.With the presented suggestions,we hope to address the current major challenges in the surveillance and prevention of microbiome-related avian influenza with the“One Health”approach.

“Body bags ready”: Print media coverage of avian influenza in Australia

In 2006 the avian influenza A (H5N1) virus received considerable media coverage in Australia, as it did in many other countries. It is often argued that the media sensationalizes health crises, and experts cautioned about the risk of panic as a result of fear of avian influenza. The purpose of the present study was to systematically analyze Australian print media coverage of avian influenza in 2006 and to examine whether this coverage served the purpose of informing, rather than alarming, the general public. For the period January 1, 2006 to December 31, 2006, 20 Australian newspaper titles were monitored for coverage of avian influenza. The identified articles were analyzed using aspects of protection motivation theory for theoretical direction to determine whether there were any consistent themes or perspectives in the coverage. A total of 850 articles were identified for analysis. Concerning vulnerability, 46% of articles reported the incidence of human cases, with 24% noting that avian influenza was a potential threat to Australia. The most common severity theme was “deadly” with over 50% of mentions, followed by “pandemic” with 35%. Only 11% of articles referred to any form of self-protection. We found that a considerable proportion of the articles reporting on avian influenza were framed in a way that had the potential to incite fear and panic amongst the public;the intensity of media coverage reduced over time;and, of particular concern, that there was little media coverage that focused on protective or preventative issues. Whether an influenza pandemic eventuates or not, it is prudent for governments and health authorities to continually develop appropriate resources and strategies to prepare the health system and the general public to respond to current, and future, infectious disease risks.

Transmission and Suppression of Avian Influenza Virus

The growth of AIV is possible with supply of minerals from aeolian desert dust, as cofactors of enzymes, and thus the blockage of the aeolian desert dusts to the poultry farmhouse is important to suppress the enzymatic activity of AIV. South Georgia of Subantarctic Islands may be the source of Continental AIV, so that Continental AIV can become endemic within the local bird population when surrounding environments are close to Subantarctica of South Georgia. There are food webs in sequence of aquatic virus, bacteria, phytoplankton, zooplankton, krill, fish and squid while penguins feed on the fish or squid infected by mutant virus to generate LPAI after an incubation period. When migratory birds move to the Continents, HPAI can spread in the Continents due to low UV-B radiation, enough feed of rice, wheat, corn, wetland, and mineral-enriched desert dust. The clean room is equipped with air washers to remove aeolian dusts and migratory birds feces from working personnel and equipments, heaters to keep the pasteurisation of ultra-high temperature at 135°C for 1 - 2 seconds to inactivate AIV, humidifier to keep wet state above 65% relative humidity for weak virus activity, and the UV-C lamps (254 nm) to finally inactivate AIV. Since AIV doesn’t like the high salinity and high relative humidity, seawater is blanketed as sprayer to maintain high salinity (>20 ppt) and high relative humidity (>65%) from the top to the bottom of the poultry farmhouses for suppression of AIV transmission from infected aeolian dust coming from outside.

Prevention of Highly Pathogenic Avian Influenza A/H5N1 Infection by Passive Immunotherapy Using Antiserum

The rapid epidemic of highly pathogenic A/H5N1 avian influenza virus by transmission from poultry to humans triggered global unrest in the pandemic of novel influenza. If a human trophic strain of avian influenza viruses replicates in livestock including pigs and chickens, it may have high infectivity and pathogenicity to humans. The most effective method of reducing the outbreaks of influenza would be prophylaxis with an effective vaccine as well as anti-viral drugs including Oseltamivir and Zanamivir hydrate. In this study, chicken antiserum against A/H5N1 virus was produced: the antisera from immunized adult chicken had a strong binding activity to A/H5N1 viral antigens by ELISA. Furthermore, the antiserum strongly inhibited hemaggregation of erythrocytes and cytopathic effects in MDCK cells, indicating a strong neutralization activity against A/H5N1 infections. Interestingly, the mortality rate of chicks inoculated with A/H5N1 virus was dramatically decreased with the antiserum injection. These results suggest that antiserum may be a potentially effective protective and therapeutic modality for A/H5N1 infection.

Suppression of Highly Pathogenic Avian Influenza A/H5N1 Infection Using Migratory Antibody Passed from Mother to Chick

Avian influenza is the most contagious disease not only in poultry, but also in humans. Avian influenza in humans occurs mainly in Southeast Asia, but no human-to-human pandemic has occurred. Meanwhile, outbreaks of avian influenza in poultry occur on a global scale and cause a large economic loss. Migration antibodies passed from mother birds via eggs are said to be an important component of the immune system that protects birds from infection. Thus, the immunity status of mother birds can determine the ability of offspring to defend against infection. In this study, we investigated the presence of anti-avian influenza virus antibody in chickens hatched on a poultry farm in Indonesia and examined the involvement of migratory antibodies in protecting against virus infection by infectious experiments of highly pathogenic avian influenza in chickens. Blood was collected from randomly selected chicks, and antibodies against avian influenza virus were evaluated in all birds. Since these young birds had no history of vaccination, the antibodies were deemed to have been transferred from the mother birds. The enzyme-linked immunosorbent assay antibody titer in each bird varied. Infection of these birds with highly pathogenic avian influenza virus A/H5N1 intra-nasally resulted in a high mortality rate in chicks with low antibody titers but a low mortality rate in chicks with high antibody titers. These findings indicate that migratory antibody prevented highly pathogenic avian influenza A/H5N1 infection in chicks, suggesting that such a preventive effect could also be expected with outdoor natural infection.

Methods to detect a vian influenza virus for food safety surveillance

Avian influenza （AI）, caused by the influenza A virus, has been a global concern for public health. AI outbreaks not only impact the poultry production, but also give rise to a risk in food safety caused by viral contamination of poultry products in the food supply chain. Distinctions in AI outbreak between strains H5N1 and H7N9 indicate that early detection of the AI virus in poultry is crucial for the effective warning and control of AI to ensure food safety. Therefore, the establishment of a poultry surveillance system for food safety by early detection is urgent and critical. In this article, methods to detect AI virus, including current methods recommended by the World Health Organization （WHO） and the World Organisation for Animal Health （Office International des Epizooties, OIE） and novel techniques not commonly used or commercialized are reviewed and evaluated for feasibility of use in the poultry surveillance system. Conventional methods usually applied for the purpose of AI diagnosis face some practical challenges to establishing a comprehensive poultry surveillance program in the poultry supply chain. Diverse development of new technologies can meet the specific requirements of AI virus detection in various stages or scenarios throughout the poultry supply chain where onsite, rapid and ultrasensitive methods are emphasized. Systematic approaches or integrated methods ought to be employed according to the application scenarios at every stage of the poultry supply chain to prevent AI outbreaks.

H5N1 influenza outbreak during March 2006 in Jordan

The highly pathogenic avian influenza H5N1 pandemic motivated countries around the World to be prepared for outbreaks within their borders. Well ahead of the outbreak, in Jordan contingency plans were prepared involving all relevant bodies in both the private and public sectors and a practice was simulated to test the effectiveness of the task force and the applicability of the plan. The highly pathogenic H5N1 influenza virus was detected and confirmed in one turkey in a backyard flock comprising 12 turkeys and 25 chickens in Kufranjah, 6 km from Ajloun city, on 23 March 2006. The samples were confirmed by the following day. Control measures were implemented immediately according to the national contingency plan and complete clean up achieved by 27 March 2006. A 3 km area around the index case was designated as a control zone, with a 10 km area around the holding further designated as a surveillance zone. The objective was to stamp out the infection and approximately 20,000 birds were destroyed including all commercial and backyard flocks in the control zone. All the human contacts were examined, treated and discharged from the hospital. The immediate response from all Jordanian sectors involved in the control strategy was positive as a result of increasing awareness and training programs that were implemented six months before the occurrence of the outbreak. A total estimated economic loss posed by this outbreak including compensation was almost $US169 million. Following the outbreak, passive surveil-lance for the virus was undertaken and training and capacity building continued. Efforts made in the preparation for an outbreak paid dividends and the need for a department responsible for monitoring migratory and wild birds in Jordan was recognized. Legislation regarding biosecurity of poultry farms and poultry transport vehicles should be revised.

2022年湘南地区活禽市场禽流感病毒检测与分析

为了解湘南地区活禽批发市场和农贸市场禽流感病毒(AIV)污染状况,2022年在湘南地区5个活禽批发市场和8个农贸市场采集禽咽肛拭子958份,采用鸡胚病毒分离、血凝试验、血凝抑制试验和RT-PCR等方法进行AIV检测及分型。结果显示:在13个采样点均检测到低致病性AIV(LPAIV),总阳性率为34.0%;共检测到H2、H3、H4、H6和H9等5种亚型LPAIV,以H6(11.7%)和H9(16.4%)亚型阳性率较高;鸡咽肛拭子样品阳性率为29.9%,以H9亚型LPAIV居多,水禽咽肛拭子样品阳性率为40.8%,以H6亚型LPAIV居多;在6份水禽拭子中检测到H3、H6、H9亚型LPAIV混合感染情况。结果表明:湘南地区活禽批发市场和农贸市场LPAIV污染面较广,污染程度较为严重,以H6和H9亚型污染为主。建议活禽市场严格落实农业农村部“1110”制度;农业农村主管部门持续进行禽流感监测,尤其是针对H6和H9亚型禽流感,强化宣传和引导,增强从业人员责任意识;公众在日常生活中尽量避免直接接触活禽类,提高自我防护水平。

2020—2022年重庆市巴南区活禽市场外环境禽流感病毒监测分析

目的:探究2020—2022年重庆市巴南区活禽市场外环境禽流感病毒污染情况,为人感染禽流感疫情防控提供科学依据。方法:随机采集巴南区4个活禽市场的环境样本,包括宰杀或摆放禽肉案板表面的擦拭标本、粪便标本、笼具表面擦拭标本,采用全自动核酸提取仪和实时聚合酶链式反应对标本进行通用甲型流感病毒检测,阳性样本再进一步按照H5、H7、H9亚型分型,结果采用Excel 2021和SPSS 24.0软件统计分析。结果:巴南区禽流感阳性检出率为39.27%,不同年份禽流感阳性率差异无统计学意义(χ^(2)=3.580,P=0.166)。H5、H7、H9、H5+H9、H7+H9、H5+H7+H9和未分型阳性率分别为9.59%、0.58%、42.73%、15.41%、0.29%、0.29%、31.10%,其中H9病毒亚型占比最高(42.73%),检出H7+H9(0.29%)、H5+H9(15.41%)、H5+H7+H9(0.29%)3种混合型样本。D农贸市场检出阳性率最高(47.81%),且不同监测场所禽流感阳性率差异具有统计学意义(χ^(2)=23.406,P<0.001);粪便标本、笼具标本、案板擦拭标本阳性检出率分别为39.31%、39.38%和39.11%,差异无统计学意义(χ^(2)=0.086,P=0.958);不同季度禽流感阳性检出率差异无统计学意义(χ^(2)=5.025,P=0.170)。结论:重庆市巴南区禽流感污染主要以H9为主,且阳性未分型样本占比较大,污染高峰为第一季度和第二季度。应加强对农贸市场禽流感病毒的实时监测,以及对禽类笼具、加工用具的消毒与灭菌。

家禽规模场禽流感疫情分析及综合防治措施

禽流感即人们所熟悉的禽流感病毒,以禽类多发,到目前也发现会传染包括人在内的哺乳动物,常见有马、猪,还有鲸鱼或海豹等。禽流感早已属于全球性传染病,特别多发于冬季和春季,其传染源主要是已患病的或携带该病毒的家畜家禽或野禽。禽流感的致病力也是不同的,毒力最强的是高致病性禽流感,其次是低致病性禽流感,还有一种是非致病性禽流感。高致病性禽流感致病力最强,可通过气溶胶、排泄物、食物等介质在群体之间水平方向传染,传播快,范围广,死亡率高。禽流感疫情带给家禽养殖业的影响是毁灭性的,家禽规模场必须做好预防管理,严格免疫、消毒、通风及饲料用药管理,完善好基础系统免疫,保证家禽养殖持续健康发展。

First Positive Detection of H9 Subtype of Avian Influenza Virus Nucleic Acid in Aerosol Samples from Live Poultry Markets in Guangxi, South of China

Avian influenza has become a serious public health problem. Risk factors for human cases are direct or closed contact with ill, died poultry and live poultry markets （LPMs） exposure.

Genetic and Molecular Characterization of H9N2 Avian Influenza Viruses Isolated from Live Poultry Markets in Hubei Province, Central China, 2013–2017

H9N2 subtype avian influenza virus(AIV)is an influenza A virus that is widely spread throughout Asia,where it jeopardizes the poultry industry and provides genetic material for emerging human pathogens.To better understand the epidemicity and genetics of H9 subtype AIVs,we conducted active surveillance in live poultry markets(LPMs)in Hubei Province from 2013 to 2017.A total of 4798 samples were collected from apparent healthy poultry and environment.Realtime RT-PCR revealed that the positivity rate of influenza A was 26.6%(1275/4798),of which the H9 subtype accounted for 50.3%(641/1275)of the positive samples.Of the 132 H9N2 viral strains isolated,48 representative strains were subjected to evolutionary analysis and genotyping.Phylogenetic analysis revealed that all H9N2 viral genes had 91.1%–100%nucleotide homology,clustered with genotype 57,and had high homology with human H9N2 viruses isolated from2013 to 2017 in China.Using a nucleotide divergence cutoff of 95%,we identified ten distinct H9N2 genotypes that continued to change over time.Molecular analysis demonstrated that six H9N2 isolates had additional potential glycosylation sites at position 218 in the hemagglutinin protein,and all isolates had I155 T and Q226 L mutations.Moreover,44 strains had A558 V mutations in the PB2 protein and four had E627 V mutations,along with H9N2 human infection strains A/Beijing/1/2016 and A/Beijing/1/2017.These results emphasize that the H9N2 influenza virus in Hubei continues to mutate and undergo mammalian adaptation changes,indicating the necessity of strengthening the surveillance of the AIV H9N2 subtype in LPMs.

Genomic characterizations of H4 subtype avian influenza viruses from live poultry markets in Sichuan province of China, 2014–2015

Dear Editor,Avian influenza viruses (AIVs) have posed a serious threat to poultry production and public health. To date, more than fourteen AIV subtypes that are able to infect human beings have been documented. Also, it is suggested that new subtypes may be reported in the future, owing to the migration of wild birds and live poultry transportation (Gao, 2018).Poultry may act as a potential incubator for novel subtypes of avian influenza virus (Bi et al., 2016a; Bi et al., 2016b; Liu et al., 2014a; Su et al., 2017). Up to date, the H7N9 AIV emerged in February 2013 has caused 1,567 human cases,with a fatality rate of 39.2%(http://www.who.int/influenza/

Risk factors for avian influenza virus in backyard poultry flocks and environments in Zhejiang Province,China:a crosssectional study

Background:Human infection of avian influenza virus(AIV)remains a great concern.Although live poultry markets are believed to be associated with human infections,ever more infections have been reported in rural areas with backyard poultry,especially in the fifth epidemic of H7N9.However,limited information is available on backyard poultry infection and surrounding environmental contamination.Methods:Two surveillance systems and a field survey were used to collect data and samples in Zhejiang Province.In total,4538 samples were collected by surveillance systems and 3171 from the field survey between May 2015 and May 2017,while 352 backyard poultry owners were interviewed in May 2017 by questionnaire to investigate factors influencing the prevalence of avian influenza A virus and other AIV subtypes.RT-PCR was used to test the nucleic acids of viruses.ArcGIS 10.1 software was used to generate maps.Univariate and logistic regression analyses were conducted to identify risk factors for AIV infection.Results:Of the 428 poultry premises observed by the surveillance system,53(12.38%)were positive for influenza A virus.Of the 352 samples from poultry premises observed by field survey,13(3.39%)were positive for influenza A virus.The prevalence of AIV was unevenly distributed and the dominant subtype differed among cities.Eastern(Shaoxing and Ningbo)and southern(Wenzhou)cities exhibited a higher prevalence of AIV(16.33,8.94,and 7.30%respectively).Contamination of AIV subtypes was most severe in January,especially in 2016(23.26%,70/301).The positive rate of subtype H5/H7/H9 was 2.53%(115/4538).Subtype H5 was the least prevalent,while subtypes H7 and H9 had similar positivity rates(1.50 and 1.32%respectively).Poultry flocks and environmental samples had a similar prevalence of AIV(4.46%vs 5.06%).The type of live birds was a risk factor and the sanitary condition of the setting was a protective factor against influenza A contamination.Conclusions:AIV subtypes were prevalent in backyard poultry flocks and surrounding environments in Zhejiang Province.The types of live birds and sanitary conditions of the environment were associated with influenza A contamination.These findings shine a light on the characteristics of contamination of AIV subtypes and emphasize the importance of reducing AIV circulation in backyard poultry settings.

2022年湖南省家禽H7N9亚型禽流感监测与分析

为了解湖南省家禽(鸡、鸭、鹅)H7N9亚型禽流感的免疫抗体水平及其流行情况,2022年在全省14个市州,采用配额抽样方法,在种禽场、商品代场、散养户和活禽市场共采集46112份禽血清和53246份禽拭子样品,通过血凝抑制试验、荧光定量PCR方法分别进行免疫抗体和病毒核酸检测。结果显示:H7N9亚型禽流感免疫抗体平均场群合格率为93.27%,平均个体合格率为90.60%,仅在活禽市场的1份鸡拭子样品中检测到病毒核酸阳性;鸡H7N9亚型禽流感免疫抗体平均场群合格率和个体合格率(94.66%和91.51%)均高于水禽(83.26%和81.86%);种禽场的免疫抗体平均场群合格率和个体合格率最高,活禽市场最低,两者差异具有统计学意义(P<0.05);全省14个市州的H7N9亚型禽流感免疫抗体平均场群合格率和个体合格率均在70%以上。结果表明:2022年湖南省家禽H7N9亚型禽流感免疫效果较好,在饲养场禽群中也未检出病原,发生大规模疫情的风险较低,但在活禽市场中仍检出病原,且水禽以及散养户和活禽市场禽群的免疫抗体水平略低,疫情散发风险依然存在。建议进一步加强对H7N9亚型禽流感的免疫监测以及动物检疫监管工作,不断提升公共卫生安全防护水平。

H5亚型禽流感病毒的危害与疫苗研究进展

H5亚型禽流感病毒(AIV)在全球范围内的广泛传播,对禽类养殖业健康发展与公共卫生安全都造成了巨大威胁。本文阐明了以H5N1、H5N6、H5N8亚型为代表的H5亚型AIV引发的国内外多起家禽和野鸟疫情,使家禽养殖业蒙受严重损失,且H5亚型AIV易变异和重组的特点,增加了疫情防控难度,同时也极易引发跨越物种屏障向人传播事件,危害公共卫生安全等问题;系统阐述了灭活疫苗等不同种类AIV疫苗的研发进展,强调了当前灭活疫苗应用最为广泛,但亚单位疫苗、DNA疫苗、多肽疫苗等新型疫苗正日益获得关注。本文以期为禽流感疫情暴发预警,“同一健康”理念宣贯,以及疫苗研发提供理论支持。