Avian influenza 流 Presented by R Supervised by 念 1
2
流 行 流 行 20000 90%: >65 y/o 流 行 200000 流 行 6 金 CDC, USA 3
流 行 力 狀 狀 4
流 行 狀 流 冷 5
6
7
流 流 流 流 流 臨 8
流 (Influenza ) 9
influenza 10
Influenza orthomyxovirus, RNA virus Type : A, B, C designation: M protein of virus envelope, nucleoprotein All influenza virus affecting animals (equine, swine, avian) : type A Subtyping : surface Ag 15 hemagglutinin ( HA ) 9 neuroaminidase ( NA ) human infection : H1, H2, H3; N1, N2 HA : viral attachment to cell membrane, induce antibody NA : virus release 11
12
13
流 離 年 度 14
流 HA attach on receptor on cell surface Human 2 6 sialic acid linked to galactose 類 Avian 2 3 sialic acid linked to galactose antigenic shift : ressortment between human & animal viruses major change of HA or NA global pandemic only in influenza A irregular interval about 10 + yrs antigenic drift : minor variation with the same subtype continuous change in influenza A & B epidemic influenza B change more slowly 15
16
17
18
流 流 流 流 流 臨 19
流 Avian influenza ( AI ) AI = fowl plague = bird flu History : first described in 1878, disease of chicken in Italy proved as one of influenza viruses in 1955 highly pathogenic AI (HPAI) in recent yrs: Australia (H7), England (H7), South Africa (H5), Scotland (H5), Ireland (H5), Mexico (H5), Pakistan (H7), USA (H5), China( H9N2), HK (H5) actual incidence:? 20
流 Avian influenza ( AI ) 流 行 北 年 流 量 30 % 11 數 0.01 不 便 兩 類 便 流 便 來 21
類 22
流 Avian influenza ( AI ) 流 : (Eurosia) (American) : 3~7 流 : 流 不 類 :,,, 力 LPAI HPAI 23
流 Avian influenza ( AI ) 率 降 狀 泌 度 羽 神 狀 暴 流 行 例 不 狀 ~ 狀 24
Fig. 1 Edema of the wattles Fig. 2 Opened edematous wattle 25
Fig. 3 Cyanotic comb of an infected chicken on the left compared to a normal chicken on the right. 26
Fig. 4 Congestion and petechiae in the skin on the hocks and shanks. 27
Fig 5. watery eyes and sinuses Fig 6. hemorrhage of trachea Photos Copyright FAO 1997 28
Fig 7. Hemorrhage of intestine 29
A color atlas and test on avian influenza Capua & F. Multinelli, 2001 30
流 流 流 流 流 臨 31
流 Avian influenza ( AI ) (OIE): (HPAI), (LPAI) HPAI 來 H5 H7 LPAI 流 異 HA 切 cleavability HPAI 數 切 Virulent virus HA cleaved without trypsin Avirulent virus HA can not cleaved without trypsin 32
流 流 流 流 流 臨 33
34
流 飼 便 不 猪 數 35
36
流 流 流 流 流 臨 37
Impact of AI on human (1) AI ( H5N1) ( A/Hong Kong/156/97 ): isolated from a tracheal aspirate obtained from one 3 y/o child in HK with a fatal illness All 8 RNA segments were derived from an AI virus 18 persons developed serious d z of AI, 6 p t died in HK in 1997 The source of human infection of 18 cases: close contact with live infected poultry the practice of marketing live poultry directly to consumers should be discouraged Feb 2003 in HK: one 9 y/o boy & his father got AI ( H5N1 ) after visiting Mainland China Since mid-dec, 2003: outbreak of AI ( H5N1): Korea, Japan, Viet Nam, Thailand, Cambodia, Indonesia 38
Impact of AI on human (2) S/S of AI in human : like URI, fever, malaise, sore throat, cough, conjunctivitis H9N2 in Hong Kong, 1999 : 2 children got mild encephalitis totally recovery H7N7 in Netherlands ( Feb. ~ Mar.2003 ): Virus (+) : 86 poultry workers, 3 of their family members Human-to-human transmission 89 p ts : 68 with conjunctivitis ( pus : 48 % ) 5 with conjunctivitis + influenza-like illness 2 with influenza-like illness 1 expired due to ARDS PNAS 2004; 101(5) 39
Impact of AI on human (3) Pandemic : (1) a novel influenza strain than can infect humans (2) all or most of the human population has no antibody (3) capable of human-to-human infection Risk of AI (H5N1) infection among health care workers exposed to p ts with AI, Hong Kong : Eight ( 3.7% ) of 217 exposed and 2 ( 0.7% ) of 309 nonexposed HCWs were H5N1 seropositive ( P=0.01 ) J Infect Dis 2000; 181:344-8 Antibody response in individuals infected with AI ( H5N1 ) viruses and detection of anti-h5 antibody among household and social contacts One H5 Ab-positive household contact, with no hx of poultry exposure, provided evidence that human-to-human transmission of AI may have occurred through close physical contact with p t Social exposure to case p ts was not associated with H5N1 infection J Infect Dis 1999:180:1763-70 40
Impact of AI on human (4) Still no convincing evidence to date of human-to-human transmission WHO : no restriction on travel to any country with H5N1 AI outbreak Suggest travelers: avoid contact with live animal markets and poultry farms Implication for food safety: Influenza viruses : destroyed by heating & drying Well protected in organic material and manure for up to 105 days Good hygiene practice during handling of poultry products, including hand washing prevention of cross-contamination and thorough cooking 41
流 類 寮 陸 類 H5 H5N1 H5N1 H5N2 H5 H5N1 H5N1 H5 H7 H5N1 H5N1 2004 年 1 30 WHO 42
類 流 例 (H5N1) 例 數 數 5 5 18 13 數 23 18 2004.2.10 WHO 43
44
北 年 陸 省 了 降 落 陸 流 陸 流 省 數 流 陸 類 流 陸 飼 猪 了 不 流 陸 來 陸 流 來 陸 45
WHO: 若 pandemic 度, 兩 年 28 65,5700 1 2300,100 230 療, 更 46
47
48
流 流 流 流 流 臨 49
(1) 流 里 殺 年 猪 流 陸 行 立 : 參 流 50
(2) 流 年 流 率 異 率 歷 年 年 流 年 流 利 年 年 年 落 殺 流 異 殺 流 51
類 52
不 理 流 力 異 更 易 了 來 來 流 兩 力 了 行 易 年 若 93.2.2 53
流 理 律 殺 飼 離 度 殺 殺 殺 54
(2) 流 : 力 : 56 0 C 3,60 0 C 3,100 0 C 1 : 流 ( Tamiflu ): 13, 130, 120, 2, 636, 6257 : 切,6 2 : 勵 立 立 力 流 行 理 : 55
(3) : ( 兩 流 力 立,93.2.6 流 離 56
(4) 不 殺 不 不 類 良 類 不 不 類 流 離 流 療 57
58
59
Thanks for your attention! 60