人禽流感疫情分析及其防控策略探讨

目的了解近年来人禽流感疫情情况及其流行病学特征,为有效防控人禽流感提供科学依据。方法收集2003年以来世界卫生组织、中国卫生部网站人感染高致病性禽流感疫情信息公布资料,分析其流行病学特征,探讨人禽流感防控策略。结果全球自2003年以来累计报告人禽流感确诊病例516例,死亡306例,病死率为59.30%。其中,中国累计报告确诊病例40例,死亡26例,病死率为65.0%,高于全球平均水平;冬、春季为疫情高发季节;儿童、青壮年多发,中青年病死率较高;男女发病率间无显著性差异。结论人禽流感病死率高,病毒可能已经发生变异并突破种间屏障,传播能力增强,人传人风险增加,对人类危害大。应积极采取措施,有效防控人禽流感的发生。     

中国人感染高致病性禽流感流行特征分析

目的 了解人感染高致病性禽流感的流行情况,分析其流行病学特征,为有效防控人感染高致病性禽流感提供科学依据.方法 收集卫生行政部门网站人禽流感疫情公布信息及媒体报道,分析其流行病学特征.结果 我国自2003年以来人禽流感累计报告确诊病例38例,年平均发病率仅为0.00041/10万,病死率很高,年平均病死率65.79%.冬春季高发共发病29例,占病例总数的76.31%.疫情呈散发状态,现已波及全国16个省份.发病年龄以10～30岁组居多,共27例,占71.05%;男女发病性别比为1:1.11;农民、学生和外来务工人员发病较多,占68.42%.已发生3起可疑聚集性人禽流感病例事件,人传人可能性增加.结论 应开展不明原因肺炎病例的排查和管理,研究有效治疗方案,降低病死率;加强宣传、人员培训和部门协调力度;完善联防联控机制,有效防控人禽流感的发生.     

2015-2016年湖北省人感染H7N9禽流感病例流行病学特征与防控实践

目的 分析湖北省人感染H7N9禽流感病例流行病学特征与疫情防控工作实践,为后续疫情防控工作提供指导与借鉴.方法 通过中国疾病预防控制信息系统监测、现场流调、实验室检测等方法,通过对2015年、2016年湖北省报告的2例人感染H7 N9禽流感病例流行病学、临床资料进行整理分析,研判湖北省人感染H7N9禽流感疫情发病危险因素,总结前期防控工作实践经验.结果 2015年湖北省首例病例为外省输入带毒活禽感染致病,2016年首例病例为外省输入性病例.2013-2015年湖北省农业部门、林业部门相关监测点未监测到H7N9禽流感病毒阳性活禽、野鸟,卫生部门、农业部门监测点外环境监测也为阴性.结论 2015-2016年湖北省人感染H7N9禽流感主要危险因素是带毒动物及病例输入.人感染H7N9禽流感联防联控机构应早部署,并加强对医务人员,特别是市级以下基层医务人员培训,以有利于疫情早发现、早处置.     

人感染H7N9禽流感的研究进展

人感染H7N9禽流感是一种新发传染病,自2013年首次出现以来,在中国已经经历了5波疫情的流行阶段。本文就人感染H7N9禽流感病毒的病原学、流行病学、临床特征及防控策略进行综述,为加深对疾病的了解以及有效开展防控工作提供参考。     

浙江省人感染H7N9禽流感流行特征与防控对策

目的 分析人感染H7N9禽流感的流行特征、研究进展和目前防控面临的问题,提出防控对策.方法 采用流行病学个案调查与描述性分析方法,收集人感染H7N9禽流感确诊病例流行病学和防控措施相关资料,分析病例流行病学特征和疫情防控措施效果.结果 浙江省共确诊人感染H7N9禽流感病例44例,死亡6例;男性27例,占61.36％;平均年龄60.18岁(32 ～ 86岁);≥50岁35例,占79.55％;农民和离退人员30例,占68.18％.40例(90.91％)集中于杭州和湖州.78.38％(29/37)有慢性基础性疾病,78.95％ (30/38)发病前有禽类暴露史;病例的1004名密切接触者均未发现感染.病例可疑暴露场所外环境标本H7N9阳性率高达43.21％ (35/81).暂停市场活禽交易对控制疫情有效.结论 人感染H7N9禽流感流行特征尚未完全明了,需要多部门联合开展监测、研究和防控.     

广东省人感染H7N9禽流感流行特征与防控对策

目的分析广东省人感染H7N9禽流感的流行特征、当前防控对策的执行效果,为防控对策调整完善提供科学依据。方法采用描述性流行病学方法,收集广东省人感染H7N9禽流感确诊病例和防控措施相关资料,分析病例流行病学特征和疫情防控措施效果。结果广东省共确诊人感染H7N9禽流感病例179例,死亡49例;病例散发于省内16个地级市;冬春两季多发;中老年人高发;以农民和离退休人员为主,大多有基础性疾病史;大部分病例在发病前有明确的禽类暴露史;死亡率与年龄成正比。关闭活禽市场暂停活禽交易对控制疫情有效。结论人感染H7N9禽流感流行特征未完全明了,实行"休市对策"对控制疫情有效,但不能彻底切断传染源,须进一步探索"冰鲜对策"。     

遵义市首例人感染H7N9禽流感病例的流行病学调查

目的对遵义市首例人感染H7N9禽流感病例的流行病学调查分析,为遵义市下一步更好防控人间禽流感疫情提供依据。方法采用流行病学个案调查与描述性分析方法,收集人感染H7N9禽流感病例流行病学资料,分析病例流行病特征。结果病例经国家CDC检测结果为禽流感病毒(H7N9)核酸检测阳性,确诊为人感染高致病禽流感病例。患者的密切接触者中均未发现异常临床表现。结论该市高致病禽流感防控工作形势严峻,要认真落实各项防控措施,防止禽流感疫情向人间扩散与传播。     

晋江市7例人感染H7N9禽流感病例流行病学特征分析

目的 分析晋江市7例人感染H7N9禽流感病例的感染途径和流行病学特征,为防控提供参考.方法 回顾性分析2014-2020年晋江市7例人感染H7N9禽流感病例的个案调查资料,分析其流行病学特征.结果 晋江市2014-2020年共报告人感染H7N9禽流感7例,病例多在冬春季,男女性别比为4:3,职业以家务及待业为主;外环境...     

南宁市首例人感染H7N9禽流感病例的流行病学特征与防控对策

目的分析南宁市首例人感染H7N9禽流感病例的流行病学特征,对采取的防控对策进行总结。方法运用描述性流行病学方法对病例、密切接触者、可疑暴露者开展流行病学调查,相关标本采用RT-PCR方法进行H7N9病毒核酸检测。评价疫情防控措施效果。结果南宁市首例人感染H7N9禽流感病例在AZJ农贸市场从事活禽贩卖宰杀工作,2017年2月18日确诊,2月19日抢救无效死亡,感染途径可能为禽到人或禽到环境到人。疫情发生后南宁市启动Ⅲ级应急响应,落实各项防控对策,未出现二代病例。结论南宁市首例人感染H7N9禽流感病例属于散发病例,未发生人间传播,Ⅲ级应急响应防控对策有效控制了疫情的扩散。     

多管齐下 信息透明——政府全力防控人禽流感疫情

自2003年禽流感疫情爆发以来,据世界卫生组织的统计报告全球人禽流感疫情统计,截止到2009年2月11日,全球感染禽流感病例总共407例,死亡人数254人。其中中国发现病例共38例,死亡人数25人,已成为人禽流感疫情高发区域之一。     

福建省3例人高致病性禽流感病例流行病学调查分析

[目的]分析福建省3例人禽流感病例流行病学特征,为防控提供科学依据。[方法]采用流行病学调查方法,阐述人感染高致病性禽流感病例的流行病学特征、实验室检测、可能的感染来源或暴露因素等。[结果]3例人禽流感病例均发生在冬春季节,早期临床症状无特异性,发病后约1周病情突然急剧加重;虽然均有可疑暴露因素,但无法得到实验室的证实,调查还存在一些局限因素。[结论]人禽流感病例好发于冬春季,发病后1周的临床症状急剧加重,这些特征应引起警惕并可用于鉴别诊断。人禽流感的感染来源、传播途径和影响因素等尚待进一步研究。     

广东省政府应对人感染禽流感防控政策变迁分析

人感染禽流感是我国高发的重大动物传染病疫情,造成了巨大的生命财产损失,政府积极出台防控政策以有效应对不断进化的疫情。本文以渐进决策模式为主线,借鉴多源流理论中问题、政治、政策三个影响因素以及"问题之窗"等分析理念,对广东省政府应对人感染禽流感防控政策变迁的过程进行分析。通过分析发现政府应对人感染禽流感防控政策变迁是一个渐进的过程,且变迁过程中政治因素起决定性作用。     

Genetic reassortment in pandemic and interpandemic influenza viruses

The human influenza pandemics of 1957 and 1968 were caused by reassortant viruses that possessed internal gene segments from avian and human strains. Whether genetic reassortment of human and avian influenza viruses occurs during interpandemic periods and how often humans are infected with such reassortants is not known. To provide this information, we used dot-blot hybridization, partial nucleotide sequencing and subsequent phylogenetic analysis to examine the 6 internal genes of 122 viruses isolated in humans between 1933 and 1992 primarily from Asia, Europe, and the Americas. The internal genes of A/New Jersey/11/76 isolated from a human fatality at Fort Dix, New Jersey in 1976 were found to be of porcine origin. Although none of the geographically and temporally diverse collection of 122 viruses was an avian-human or other reassortant, cognizance was made of the fact that there were two isolates from children from amongst 546 influenza A isolates obtained from The Netherlands from 1989–1994 which were influenza reassortants containing genes of avian origin, viruses which have infected European pigs since 1983–1985. Thus, genetic reassortment between avian and human influenza strains does occur in the emergence of pandemic and interpandemic influenza A viruses. However, in the interpandemic periods the reassortants have no survival advantage, and the circulating interpandemic influenza viruses in humans do not appear to accumulate avian influenza virus genes.     

Characterization of the attenuating M and NP gene segments of the avian influenza A/Mallard/78 virus during in vitro production of avian-human reassortant vaccine viruses and after replication in humans and primates

A unique requirement for live attenuated reassortant influenza vaccines is the need to generate new reassortant vaccine viruses with the appearance of each new antigenic variant. Thus, the attenuation phenotype conferred by the attenuated donor influenza virus must remain genetically stable during the generation of each new reassortant vaccine virus. In this study we used nucleotide sequence analysis to evaluate the genetic stability of the attenuating M and NP genes of the avian influenza A/Mallard/NY/6750/78 attenuated donor virus during the in vitro generation and subsequent in vivo replication of avian-human (AH) influenza A reassortant vaccine viruses in monkeys and humans. Nucleotide sequence changes in the M and NP genes occurred at a rate of approximately 0.61 substitutions/1000 nt/reassortant during in vitro generation of four AH reassortant viruses. Only two nucleotide sequence changes occurred in the M and NP gene segments of four isolates of H1N1 or H3N2 AH vaccine viruses following 6-8 days of replication in seronegative children, and neither change affected amino acids previously identified as playing a potential role in attenuation. In addition, there were no changes in the nucleotide sequence of the M and NP genes of single gene AH reassortant viruses following five serial passages in squirrel monkeys. Finally, there was no change in the level or duration of replication of the single gene reassortant viruses in the upper or lower respiratory tract of monkeys following serial passage.(ABSTRACT TRUNCATED AT 250 WORDS)     

广东和香港地区甲型H1N1流感流行与防控比较

目的对粤港两地2009年甲型H1N1流感流行与防控情况进行分析比较,为两地协同开展防控工作提供依据。方法通过广东省甲型H1N1流感信息管理系统收集广东省甲型H1N1流感的流行资料,香港的资料来源于香港卫生署卫生防护中心提供的"人类猪型流感和季节性流感直击"及"传染病直击"。对收集到的两地资料进行描述性流行病学分析。结果截至2009年9月15日,广东省共报告甲型H1N1流感病例1 606例,香港共报告18 687例;广东省经历首例输入性病例(发病时间为5月14日)到首例本地感染病例的时间(输入过程)为12 d,首例本地感染到首起聚集性病例的时间(本地传播过程)为15 d,而香港首例输入性病例发病时间为4月28日,经历输入过程时间较长(36 d)、经历本地传播过程的时间较短(5 d);两地均在6月中旬经历一个小的发病高峰,但7月10日后香港报告病例数直线上升,而广东省只是小幅波动;经过7、8月暑期的平息期,9月开学后两地甲流暴发疫情大量发生,截至9月26日,广东省共报告学校甲型H1N1流感暴发疫情100起,香港共报告流感样病例暴发935起,其中36起为甲流疫情;广东流感监测哨点医院流感阳性标本中甲型H1N1流感病毒构成比从第27周(至7月12日)的1.9%上升至第38周(至9月27日)的58.0%,而香港则从第23周(至6月14日)的1.9%上升至第38周的62.8%,成为当地流感的优势毒株。在疾病的输入期和本地传播期两地均根据疫情的不同特点制定了相应的防控策略,防控重点从预防输入(口岸检疫、隔离)到减缓扩散(加强社区监控)逐步改变。结论2009年广东省和香港经历了新发传染病甲流在本地输入、传播和流行的过程,研究发现两地甲流的传播、流行时间相当接近,说明粤港两地携手防控的重要性。     

Update: influenza activity--United States and worldwide, 2002-03 season,and composition of the 2003-04 influenza vaccine

In collaboration with the World Health Organization (WHO), its collaborating laboratories, state and local health departments, health-care providers, and vital statistic registries, CDC conducts surveillance to monitor influenza activity and to detect antigenic changes in the circulating strains of influenza viruses. During the 2002-03 influenza season, influenza A (H1), A (H3N2), and B viruses co-circulated in the Northern Hemisphere. Human infections with avian influenza A (H5N1) and A (H7N7) viruses were reported in Hong Kong and the Netherlands, respectively. In the United States, the 2002-03 influenza season was mild; influenza A (H1) and B viruses circulated widely, and the predominant virus varied by region and time of season. This report summarizes influenza activity in the United States and worldwide during the 2002-03 influenza season and describes the composition of the 2003-04 influenza vaccine.     

公众流感疫苗认知、接种现状及影响因素分析

目的 了解公众流感疫苗认知、接种现状及影响因素,为提高流感疫苗接种率提供科学依据。 方法 2020年1月15日—4月30日期间,使用12320公益电话平台,对广州、廊坊、南京、苏州、太原和重庆等6地区公众流感疫苗认知和2019—2020年流感季流感疫苗接种现状开展电话调查,采用多因素logistic回归模型分析影响不同年龄段公众流感疫苗接种率的相关因素。 结果 有效应答共计12 263人。2019—2020年流感季,16.34%(1 959/11 989)受访者曾咨询过流感疫苗接种事宜,流感疫苗接种比例为12.95%(1 529/11 810),其中6月龄~5岁儿童接种比例为26.84%(877/3 267),6~17岁学生为14.78%(245/1 658),18~59岁成年人为3.99%(199/4 989),≥60岁老年人为10.97%(208/1 896)。仅5.22%(202/3 866)受访者认为流感疫苗不安全,74.85%(3 785/5 057)认为流感疫苗具有中等和较好的保护效果。多因素logistic回归分析显示,免费接种、咨询流感疫苗接种、认为流感疫苗保护效果好、接种方便可促进流感疫苗的接种。 结论 公众对流感疫苗安全性和保护效果认可度较高,作为流感重症高危人群的5岁以下儿童和老年人需要进一步提升流感疫苗接种覆盖率。加大对流感疫苗相关知识宣传力度,提供便捷的咨询和接种服务可提高公众流感疫苗接种率。     

United States of America Department of Health and Human Services support for advancing influenza vaccine manufacturing in the developing world

Since 2005, the Government of the United States of America has provided more than US$ 50 million to advance influenza vaccine development in low-resourced countries. This programme has provided a unique opportunity for the US Government to develop a comprehensive view of, and to understand better the challenges and future needs for influenza vaccines in the developing world. The funding for this programme has been primarily through a cooperative agreement with the World Health Organization (WHO) to support directly its capacity-building grants to government-owned or -supported vaccine manufacturers in developing countries. A second cooperative agreement with the Program for Appropriate Technologies in Health (PATH) was initiated to accelerate the completion of a current Good Manufacturing Practice cGMP production facility, along with supporting facilities to obtain a reliable source of eggs, and to conduct clinical trials of influenza vaccine manufactured in Vietnam. This mechanism of utilizing cooperative agreements to support capacity-building for vaccine development in low-resourced settings has been novel and unique and has yielded fruitful returns on minimal investment. The information derived from this programme helps to clarify not only the development challenges for influenza vaccines and how the United States may assist in meeting those challenges, but also other vaccine development issues common to manufacturers in developing countries. While building the initial capacity to produce influenza vaccines can be a straightforward exercise, the sustainability of the enterprise and expansion of subsequent markets will be the key to future usefulness. There is hope for expansion of the global influenza vaccine market. Ongoing burden of disease studies are elucidating the impact of influenza infections, particularly in children, and more countries will take note and respond accordingly, since respiratory diseases are now the number one killer of children under five years of age. In addition to achievements described in this issue of Vaccine, the programme has been successful from the US perspective because the working relationships established between the US Department of Health and Human Services' (HHS) Assistant Secretary for Preparedness and Response Biomedical Advanced Research and Development Authority (BARDA) and its partners have assisted in advancing influenza vaccine development at many different levels. A few examples of BARDA's support include: establishment of egg-based influenza vaccine production from "scratch", enhancement of live attenuated influenza vaccine (LAIV) production techniques and infrastructure, completion of fill/finish operations for imported bulk vaccine, and training in advanced bio-manufacturing techniques. These HHS-supported programmes have been well-received internationally, and we and our partners hope the successes will stimulate even more interest within the international community in maximizing global production levels for influenza vaccines.     

Nosocomial pandemic (H1N1) 2009, United Kingdom, 2009-2010

To determine clinical characteristics of patients hospitalized in the United Kingdom with pandemic (H1N1) 2009, we studied 1,520 patients in 75 National Health Service hospitals. We characterized patients who acquired influenza nosocomially during the pandemic (H1N1) 2009 outbreak. Of 30 patients, 12 (80%) of 15 adults and 14 (93%) of 15 children had serious underlying illnesses. Only 12 (57%) of 21 patients who received antiviral therapy did so within 48 hours after symptom onset, but 53% needed escalated care or mechanical ventilation; 8 (27%) of 30 died. Despite national guidelines and standardized infection control procedures, nosocomial transmission remains a problem when influenza is prevalent. Health care workers should be routinely offered influenza vaccine, and vaccination should be prioritized for all patients at high risk. Staff should remain alert to the possibility of influenza in patients with complex clinical problems and be ready to institute antiviral therapy while awaiting diagnosis during influenza outbreaks.