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The author:(作者)归海一刀
published in(发表于) 2014/1/30 6:30:33
CDC experts said outbreaks H7N9 outbreak during the Spring Festival， and

　　The core reading

So far this year China has H7N9 avian influenza 110 cases of confirmed human infections, including Zhejiang, Guangdong, Shanghai, 20 cases of death. Recently, the number added each week H7N9 avian flu confirmed cases of infection in China is close to the peak of the outbreak last year levels.

Disease control experts say, H7N9 viruses cannot be transmitted effectively in the crowd. No outbreaks of human infection H7N9 avian influenza outbreak during the lunar new year.

　　H7N9 cannot be transmitted effectively in the crowd

Feng Zijian, China CDC Deputy Director said in an interview, H7N9 avian flu H5N1-like, with a high seasonal pattern in winter and spring. Some sporadic cases will continue to occur in urban areas.

National Influenza Center Director Shu Yue long believed that H7N9 avian influenza virus infection, transmission, virulence, drug resistance and other major indicators have not changed, did not find a virus variation with public health significance, does not have the biological basis of widely spread throughout the crowd, didn't appear to have the ability to effectively spread in the crowd, so expertise for its risk assessment did not change.

Said Shu Yuelong, as long as the infection under control, can effectively control the disease. In future, the human infection H7N9 avian influenza sporadic cases still occur, but the possibility of a pandemic occurring is small.

Feng Zijian pointed out that current H7N9 avian influenza human infection is limited person-to-person transmission, not one case occurred in three generations of transmission. So-called limited person-to-person transmission, referring to the occasional person to person, only a handful of second generation cases, almost no cases of three generations. And effective person-to-person transmission is occurring in many patients, infected persons can spread a number of persons occurred more than three generations, four generations of patients, and even causing community outbreaks.

Feng Zijian introduction about limited person-to-person transmission and effective person-to-person transmission, an indicator--basic epidemiological transmission. When the spread is greater than 1 o'clock, 1 people living with HIV infection more than 1 person, are efficient person-to-person transmission. When the spread is less than 1 o'clock was limited person-to-person transmission. According to the Mathematic model analysis, H7N9 basic communication only 0.09 per cent, only a limited, non-sustained person to person. Only individual cases have been detected in several cases, and is the second generation of cases. In his view, the movement of people during the Spring Festival does not increase the risk of virus transmission.

Shu Yuelong pointed out that from the pathogen's perspective, in close contact with a chicken H7N9 virus infection of H7N9 infection and close contact with a person, essentially no difference. The only difference is that if an infection occurs, first generation spread, second call second generation transmission. Therefore, you don't have to read too much into the second generation transmission.

Feng Zijian introduced, currently scientists on H7N9 virus of consensus has following several points: a is virus up stems from poultry, main in poultry class in the pop, people just in accidentally situation Xia contact poultry class or virus infection; II is and H5N1 virus compared to, H7N9 virus more easy infection people; three is H7N9 virus still no from avian influenza virus of features, does not like seasonal influenza as in room widely spread; four is pathogenic sexual comparison strong, easy led to heavy syndrome infection.

Shu Yuelong stressed that, based on current knowledge, unanticipated H7N9 virus trends. Therefore, H7N9 avian influenza human infection diagnosis and treatment programmes (2014) stressed the need to strengthen pathogen monitoring. Only close monitoring in order to understand the virus mutates.

At present, human infection H7N9 avian influenza was classified as category b infectious diseases, in accordance with the relevant provisions, the State Administrative Department of public health announced an outbreak a month. However, as the emerging infectious diseases, each case must be communicated to the World Health Organization.

　　Confirmed cases of 70% have a history of contact with live poultry

Said Feng Zijian, the future trend of the epidemic, mainly depends on the levels of virus transmission and human poultry exposure levels, the chance of contracting and human contact with poultry and poultry-related.

According to reports, currently has H7N9 avian flu confirmed human infection cases, 70% has a history of contact with live poultry, 30% there is no clear history of exposure to live poultry. However, in the case where there is no history of exposure to live poultry, some in critical condition or have died, no way of knowing whether there is a history of exposure, and some cannot accurately recall whether exposure history. Last outbreak areas to close live poultry markets, after you stop the poultry cross-regional trade, significant decrease in new cases.

He reminded the public: try to avoid contact with live poultry, especially in high-risk populations, such as elderly, immunocompromised persons; try not to buy live poultry, consumption of poultry meat recommended that you choose a white chicken, chilled chicken products; and poultry exposure cannot be avoided, you should wash your hands as soon as possible after the exposure, health protection; if you develop flu symptoms, you should seek medical advice as soon as possible. Besides public habits changing poultry farming modes should also be upgraded, reducing the virus from spreading among poultry.

　H7N9 vaccine has begun declared to the drug regulatory authority

According to Shu Yue long introduction, emerging infectious diseases, vaccine research and development is very important. Only vaccines developed in order to cope with potential crises. Currently, some enterprises have basically completed the preclinical studies of human infection H7N9 avian influenza vaccines, has begun to drug regulators declared.

Director of respiratory medicine of Peking University people's hospital said Gao zhancheng, human infection H7N9 avian influenza and seasonal influenza at an early stage there were no significant differences, clinical early diagnosis difficult. Medical personnel should step up epidemiology in patients with a history of questioning, increase human infections H7N9 avian influenza early detection capabilities, as well as severe and severe treatment capacity.

Beijing Ditan Hospital Medical Center said Li Xingwang, Director of infectious diseases, H7N9 avian influenza human infection diagnosis and treatment programmes (2014) proposed, or H7N9 avian influenza testing is negative but clinical highly suspicious cases, antiviral treatment should be carried out, in the interests of patients are effectively treated as soon as possible. The new programme emphasizes enhancing drug sensitivity of diagnosis and treatment monitoring. At present, the susceptibility of Fe still has H7N9 avian flu virus.

Li Xingwang also reminded not only attaches importance to H7N9 avian influenza, should attach equal importance to other seasonal flu, because influenza viruses are likely to result in severe cases.

　　核心阅读

　　今年以来，全国已确诊人感染H7N9禽流感病例110例，其中浙江、广东、上海死亡20例。近期，我国每周新增人感染H7N9禽流感确诊病例数已接近去年疫情高峰时期水平。

　　疾控专家们指出，H7N9病毒还不能在人群中有效传播。春节期间不会暴发人感染H7N9禽流感疫情。

　　H7N9不能在人群中有效传播

　　中国疾控中心副主任冯子健在接受采访时说，H7N9禽流感类似H5N1，具有冬春季高发的季节性特征。部分城市地区仍将继续出现散发病例。

　　国家流感中心主任舒跃龙认为，H7N9禽流感病毒的感染率、传播能力、致病性、耐药性等主要指标并没有改变，未发现病毒具有公共卫生意义的变异，不具备在人群中广泛传播的生物学基础，也未见其具备了能在人群中有效传播的能力，所以专家针对它的风险评估没有改变。

　　舒跃龙说，只要把传染源控制住，就能有效控制疫情。今后，人感染H7N9禽流感散发病例还会出现，但发生大规模流行的可能性小。

　　冯子健指出，目前人感染H7N9禽流感是有限的人传人，没有一例发生三代传播。所谓有限的人传人，指的是偶尔发生人传人，只有少数二代病例，几乎没有三代病例的情况。而有效的人传人是指出现多代病人，一个感染者可以传播若干人，出现三代、四代以上病人，甚至引起社区暴发。

　　冯子健介绍，关于有限人传人与有效人传人，流行病学上有一个指标——基本传播数。当基本传播数大于1时，即1个感染者传染1个人以上，才是有效的人传人。当基本传播数小于1时，就是有限的人传人。根据数学模型分析，H7N9的基本传播数只有0.09，只能有限、非持续地人传人。在已发现的病例中仅有个别几例，且都是二代病例。他认为，春节期间人员流动不会增加病毒传播风险。

　　舒跃龙指出，从病原学的角度看，密切接触一只感染H7N9病毒的鸡和密切接触一个感染H7N9病毒的人，本质上没有任何区别。唯一的区别是，如果发生感染，第一种情况叫一代传播，第二种情况叫二代传播。因此，不必过度解读二代传播。

　　冯子健介绍，目前科学家关于H7N9病毒的共识有以下几点：一是病毒起源于禽，主要在禽类中流行，人只是在偶然情况下接触禽类或病毒感染；二是与H5N1病毒相比，H7N9病毒更容易感染人；三是H7N9病毒仍没有脱离禽流感病毒的特点，不会像季节性流感一样在人间广泛传播；四是致病性比较强，容易导致重症感染。

　　舒跃龙强调，根据现有知识，尚无法预测H7N9病毒变异的趋势。因此，《人感染H7N9禽流感诊疗方案(2014年版)》强调要加强病原学监测。只有密切监测，才能了解病毒变异情况。

　　目前，人感染H7N9禽流感被列为乙类传染病，根据有关规定，国家卫生行政部门每个月公布一次疫情。但是，作为新发传染病，每一例病例都要向世界卫生组织通报。

　　确诊病例七成有活禽接触史

　　冯子健说，未来疫情的走向，主要取决于禽间病毒传播水平和人禽暴露水平，即与禽感染和人接触禽的机会有关。

　　据介绍，目前已确诊的人感染H7N9禽流感病例中，七成有活禽接触史，三成没有明确的活禽接触史。但是，在没有活禽接触史的病例中，有一部分病情危重或已经死亡，无法得知是否有接触史，还有一部分不能准确回忆是否有过接触史。去年一些发生疫情的地区关闭活禽市场、停止禽类跨区域交易后，新发病例明显减少。

　　他提醒公众：尽量避免与活禽接触，特别是老年人、免疫力低下者等高危人群；尽量不要购买活禽，食用禽肉建议选择白条鸡、冰鲜鸡等产品；如果与禽类接触无法避免，应在接触后尽快洗手，做好卫生防护；一旦出现流感症状，应尽快就医。除了公众消费习惯有待转变，禽类养殖模式也应升级换代，减少病毒在禽间传播。

　　H7N9疫苗已开始向药监部门申报

　　据舒跃龙介绍，对于新发传染病来说，疫苗的研发非常重要。只有研发出疫苗，才能应对可能出现的危机。目前，一些企业基本完成了人感染H7N9禽流感疫苗的临床前研究，已经开始向药品监管部门申报。

　　北京大学人民医院呼吸内科主任高占成说， 人感染H7N9禽流感和季节性流感在初期没有显著差异，临床很难做到早期诊断。医务人员应加强对患者流行病学史的追问，提高人感染H7N9禽流感病例早期识别能力，以及重症与危重症救治能力。

　　北京地坛医院感染性疾病诊疗中心主任李兴旺说，《人感染H7N9禽流感诊疗方案(2014年版)》提出，对甲型流感或H7N9禽流感病原学检测虽为阴性但临床高度怀疑的病例，仍应当进行抗病毒治疗，这有利于患者尽早得到有效治疗。新版诊疗方案强调加强药物敏感性监测。目前，H7N9禽流感病毒对达菲仍具有敏感性。

　　李兴旺还提醒，不要只重视H7N9禽流感，对于其他季节性流感也要同样重视，因为流感病毒都有可能导致重症病例。

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