Avian Influenza AH 5 N 1 and Risks

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Avian Influenza A(H 5 N 1) and Risks to Human Health Keiji Fukuda Global

Avian Influenza A(H 5 N 1) and Risks to Human Health Keiji Fukuda Global Influenza Programme World Health Organization l l Technical Meeting on Highly Pathogenic Avian Influenza and Human H 5 N 1 infection Rome 27 - 29 June 2007

Major Public Health Threats of Influenza l Seasonal – Greatest health impact over time

Major Public Health Threats of Influenza l Seasonal – Greatest health impact over time l Avian influenza H 5 N 1 virus – Most often direct/indirect zoonotic infection from infected birds – Infrequently direct contact with an infected person – Other exposures not clearly established l Emergence of a human pandemic strain – H 5 N 1 most concern due to spread & pathogenicity – Another novel subtype possible

Laboratory-confirmed human H 5 N 1 cases, since 2003 312 cases 190 deaths

Laboratory-confirmed human H 5 N 1 cases, since 2003 312 cases 190 deaths

Phylogenetic tree based on H 5 HA Strains in yellow: vaccine strains Vietnam/JP 14/05

Phylogenetic tree based on H 5 HA Strains in yellow: vaccine strains Vietnam/JP 14/05 ck/Cambodia/013 LC 1 b/05 Vietnam/1194/04 Thailand Vietnam/1203/04 Vietnam/HN 30408/05 Cambodia Thailand/16/04 Vietnam/JPHN 30321/05 Hong Kong/213/03 Indonesia/CDC 523/06 Indonesia/CDC 699/06 Indonesia/CDC 326/06 Indonesia/5/05 Indonesia/CDC 184/05 Indonesia/7/05 dk/Kulon. Progo. BBVET 9/04 ck/Indonesia/CDC 25/05 Indonesia/6/05 ck/Brebes/BBVET 2/05 Indonesia/CDC 625/06* Indonesia/CDC 594/06* * Karo cluster ck/Dairi/BPPVI/05 ck/Yunnan/374/04 ck/Yunnan/115/04 dk/Guangxi/13/04 ck/Guangxi/12/04 ck/Yunnan/493/05 ck/Yunnan/447/05 whooping swan/Mongolia/244/05 bar headed gs/Qinghai/1 A/05 * Turkey/65596/06 Turkey/15/06 Iraq/207 NAMRU 3/06 ck/Nigeria/641/06 Middle east mld/Italy/332/06 turkey/Turkey/1/05 Egypt/2782 NAMRU 3/06 Europe Djibouti/5691 NAMRU 3/06 ck/Nigeria 42/06 Africa migratory dk/Jiangxi/2136/05 gs/Kazakhstan/464/05 ck/Krasnodar/01/06 Azerbaijan/011162/06 swan/Iran/754/06 dk/Laos 3295/06 Anhui/1/05 Anhui/2/05 Japanese white-eye/Hong Kong/1038/06 ck/Malaysia 935/06 Vietnam/30850/05 China Guangxi/1/05 dk/Hunan/15/04 Laos qa/Guangxi/575/05 dk/Vietnam/Ncvdcdc 95/05 migratory dk/Jiangxi/1653/05 Hong Kong/156/97 gs/Guangdong/1/96 Clade 1 Clade 2. 2 Clade 2. 3

Characteristics of confirmed H 5 N 1 human cases l M: F = 0:

Characteristics of confirmed H 5 N 1 human cases l M: F = 0: 9 l All age groups affected – Higher incidence in age group < 40 years l Case fatality ~ 63% l Median duration of illness – Onset - hospitalization 4 days – Onset - death 9 days l Clinical features – Severe cases feature pneumonia, ARDS – Asymptomatic infection appears rare

Risk factors and exposures H 5 N 1 in humans l Primary known exposures

Risk factors and exposures H 5 N 1 in humans l Primary known exposures associated with infected birds – Unprotected handling – Sharing living areas l Route of virus entry into humans uncertain l Risk appears highest in countries with infected birds where – Human contact with poultry is frequent – Animal disease detection and/or control is a challenge l No identifiable exposures for some cases

Human-to-Human H 5 N 1 Transmission l Epidemiological diagnosis of exclusion – – Plausible

Human-to-Human H 5 N 1 Transmission l Epidemiological diagnosis of exclusion – – Plausible epidemiological link No other probable exposures Viruses consistent " Limited human-to-human transmission cannot be ruled out" l Typically associated with very close prolonged contact between susceptible and severely ill person l No occurrence of human-to-human transmission capable of sustained community outbreaks

Prevention and treatment of human H 5 N 1 infection l One H 5

Prevention and treatment of human H 5 N 1 infection l One H 5 N 1 vaccine licensed but not yet field tested – Others applications in submission l Optimal antiviral treatment regimen is yet unknown – Early oseltamivir treatment might reduce H 5 N 1 -associated mortality l Antiviral resistance requires monitoring l Limited evaluation of otherapies – E. g, immuno-modulators, convalescent sera

WHO Strategic Action Plan Pandemic Influenza 1 Reduce Human Exposure to H 5 N

WHO Strategic Action Plan Pandemic Influenza 1 Reduce Human Exposure to H 5 N 1 virus 2 Strengthen Early Warning system 3 Intensify Rapid Containment operations 4 Build Capacity to cope with pandemic 5 Coordinate Global Scientific Research and Vaccine Development

WHO Global Influenza Surveillance Network

WHO Global Influenza Surveillance Network

Important Current Activities l Implementation of IHR l Continuing development of framework to facilitate

Important Current Activities l Implementation of IHR l Continuing development of framework to facilitate sharing of influenza viruses and related benefits l Maintain rapid global threat assessment & response l Clearer operating terms & conditions l Greater access of developing countries to benefits l Short to long term solutions for improving pandemic & H 5 vaccine situation l Stockpiles l Global Pandemic Influenza Vaccine Action Plan

H 5 N 1 Cluster Graph Cases in clusters l Cluster – Two or

H 5 N 1 Cluster Graph Cases in clusters l Cluster – Two or more epidemiologically linked cases – At least one has a lab-confirmed H 5 N 1 infection – Inclusion of fatal probable cases Unexplained deaths linked epidemiologically to a confirmed case (probable case)