流感防治 （含H7N9流感） 防疫醫師 蘇迎士.

Presentation on theme: "流感防治 （含H7N9流感） 防疫醫師 蘇迎士."— Presentation transcript:

1 流感防治 （含H7N9流感） 防疫醫師 蘇迎士

2 流感 A型流感 B型流感 C型流感 2 lineages Subtypes based on 2 surface Ag: Yamagata
Hemagglutinin (H) Neuraminidase (N) B型流感 2 lineages Yamagata Victoria C型流感

3 Influenza A Influenza A viruses infect a variety of species. This shows that all the H and all the N types are found in the waterfowl and shorebird reservoir. Human infections that occur yearly are most often the result of H1N1, H3N2, and H1N2 influenza A viruses. Human infections by other subtypes are sporadic, have not sustained human to human transmission, and are rare to date. Avian influenza viruses of most concern to the poultry industry are the H5 and H7 subtypes. These two subtypes are associated with high pathogenicity in domestic poultry. These viruses are of concern to human public health also because they have infected and caused serious disease in humans. Although the infections have been rare they are concerning because the human population is immunologically naïve to those subtypes. [Graphic by Travis Engelhaupt, CFSPH, ISU, CVM]

4 RNA Hemagglutinin Neuraminidase Antibodies Sialic acid
　　Antigenic drift是病毒RNA上產生了突變，如果這個突變的位置是在Hemagglutinin或者是Neuraminidase上，就會讓這個病毒逃脫了我們人體抗體涵蓋的範圍而造成感染，因為這樣子的改變只是突變所造成，所以只是小改變，病毒基本的Ｈ及N型號，是沒有改變的。 RNA Hemagglutinin Neuraminidase Antibodies Sialic acid 4

5 A型流感在物種間傳播 This diagram demonstrates the interspecies transmission of influenza A viruses and is adapted . The red arrows are direct transmissions that have occurred and caused disease. The pink arrows have not occurred but give the picture a very circular look which is consistent with the ecology of this virus. Influenza A viruses seem to be able to cross species barriers if given the right opportunity. The center of all this is the wild waterfowl, the reservoir species. [Note to speaker: Below is a brief description of each species. There is information later in the presentation on each of these so you may want to wait until then to give more information. However, if you are focusing on one species you can delete the later slides and briefly mention them on this slide.] Influenza A has caused disease in seals and whales (separate outbreaks with different viruses). The viruses appeared to have been transmitted from wild waterfowl. Equine influenza may have origins from wild waterfowl also. The virus has adapted to the equine host and circulates in that population. The H3N8 of US equine appears to have been transmitted to dogs in January of This virus has apparently adapted to its new host. In the summer of 2005 it was spread between dogs across the US. It was most prominent in racing dogs but there were cases in pet dogs also. It remains to be determined if the virus will continue to circulate in this species. Wild waterfowl are often responsible for transmission of the virus to domestic poultry. The HPAI H5N1 Asian influenza virus infected cats. Zoo cats fed infected uncooked poultry meat became infected and some domestic pet cats that were feeding on a pile of infected dead chickens became infected. The virus did not spread in cats outside of those two outbreaks. The “mixing vessel” pig can be infected by influenza viruses from wild waterfowl, humans, and domestic poultry. Influenza from swine has been transmitted to humans and caused disease. Human influenza virus has infected pigs. Some of the swine influenza viruses circulating and causing disease in the US swine population contain human influenza genes. Influenza virus from domestic poultry has sporadically infected and caused severe disease in humans, especially highly pathogenic strains. The first documented case of influenza transmitting directly from bird to human was in This is discussed later in the presentation. There have been no reports of direct transmission to human from wild waterfowl reservoir hosts. The next slide shows the many different influenza subtypes and some of the species that have been infected. [Graphic by Clint May, CFSPH, ISU, CVM - Adapted from Fields Virology, 4th edition, Lippincott Williams & Wilkins, page 1538]

6 Emergence of A/2009/H1N1 virus from other human and animal influenza viruses.
Emergence of A/2009/H1N1 virus from other human and animal influenza viruses. Influenza viruses are usually limited to infecting specific hosts, with tissue tropism and receptor specificity being important restriction factors. A change in tropism sometimes occurs, with pigs being an important “mixing vessel” due to their tracheae containing receptors with both α-2,3-linked and α-2,6-linked sialic acid moieties. In the case of A/2009/H1N1 virus, sequential reassortment of genes from human, avian, and swine influenza viruses culminates in a virus with replication competence comparable to those of other human influenza viruses. Cheng V C C et al. Clin. Microbiol. Rev. 2012;25:

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13 http://liquidbio. pbworks

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17 這次的H7N9~

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21 保護自己很重要！！

22 我國流感監測及 流行概況

23 流感監測系統 社區流感病毒監測：病毒合約實驗室監測系統 法定傳染病個案通報管理系統 (流感併發症) 定點醫師監測系統 病毒合約實驗室監測系統
人口密集機構傳染病監視系統 學校傳染病監視系統 症狀通報系統

24 社區流感病毒監測 北中南東各區共9家病毒合約實驗室 定點監測醫師每週提供2-5件上呼吸道檢體 每週回報流感病毒檢出結果及病毒分型

25 流感病毒監視

26 類流感就醫監測 急診： 門診及住院：全民健康保險申報資料庫 監測每週類流感就醫趨勢變化 約160餘家醫院急診參與，涵蓋率約80%
每日自動收集急診病患就醫診斷疾病分類碼(ICD-9) 分析類流感就診人次數及所佔比率 門診及住院：全民健康保險申報資料庫 涵蓋率>99% 收集門診及住院病患就醫診斷疾病分類碼(ICD-9) 分析類流感及住院人次數及所佔比率 監測每週類流感就醫趨勢變化

27 門診及急診類流感就醫百分比(2011/6/26至今)

28 流感群聚監測 人口密集機構傳染病監視系統 症狀通報系統 學校傳染病監視系統

29 季節性流感疫苗公費提供對象 65歲以上老人 6個月以上至國小6年級幼兒及學童 居住安養養護機構者 重大傷病證明或罕見疾病患者
從事醫事及衛生防疫工作 禽畜養殖相關工作者

30 季節性流感疫苗—三價或四價? 目前國內的季節性流感疫苗均為三價疫苗 B型流感分維多利亞株(Victoria)與山形株(Yamagata)
A (H1N1)型流感選取一株病毒株 A (H3N2)型流感選取一株病毒株 B 型流感選取一株病毒株 B型流感分維多利亞株(Victoria)與山形株(Yamagata) 三價疫苗只選取一株B型流感，無法交叉保護 疫苗株與流行病毒株不吻合，並不罕見 四價疫苗即將上市，若成為公費疫苗可解決此問題 價格較貴，且考驗民眾對於「新疫苗」的信心