Highly Pathogenic Avian Influenza Threats to Biodiversity Conservation
Highly Pathogenic Avian Influenza Threats to Biodiversity Conservation in Africa College of African Wildlife Management Mweka, Tanzania July 2008
Overview • Highly Pathogenic Avian Influenza – Introduction & History – Current Threat – Potential Impacts on Biodiversity Conservation – Preparedness and Response • Global Avian Influenza Network for Surveillance (GAINS)
Influenza A Virus • Three types of Influenza A virus: – Seasonal Influenza • Widely circulating amongst humans (cause of the “flu”) – Avian Influenza • Primarily infects birds, but other mammalian species (including humans) susceptible – Low Pathogenicity – High Pathogenicity (H 5 N 1) – Pandemic Influenza • Virus with the capacity for efficient, sustained human to human transmission
Influenza A Virus • Typified by two types of surface proteins: – Hemagglutinin (HA) – Neuraminidase (NA) • No cross immunity between seasonal and avian influenza
Highly Pathogenic Avian Influenza • HPAI defined based upon high mortality rates in domestic poultry • H 5 N 1 is the currently circulating HPAI strain
H 5 N 1 HPAI • First Identified in 1996 in Guangdong, China • Initial outbreak in domestic poultry 1997, Hong Kong – 1. 5 million chickens culled – 18 people infected; 6 died • Reemergence in Hong Kong in February 2003
Historical Influenza Pandemics • 20 th century pandemics: – 1918 (~50 million deaths globally) – 1957 (~1 million) – 1968 (~750, 000)
Belshe RB. N Engl J Med 2005; 353; 21
Pandemic Influenza Impacts • Pandemic influenza poses significant public health risk – No pre-existing immunity to H 5 N 1 in human population – Isolates have demonstrated some anti-viral resistance – Vaccine has been developed, but may not cover pandemic strain – Difficulty of containment • Projected Pandemic Costs: – 10 -180 million deaths worldwide – Economic Impact: 2 -3. 1 % of global GDP (>2 trillion USD) (World Bank)
Highly Pathogenic Avian Influenza • Bird to Bird Transmission – – – Predominant type of transmission to date Primarily still a disease of birds Viral spread via trade in poultry and poultry products Via trade in caged/exotic birds Via human movement Via wild birds • The relative importance of wild birds in transmission varies by situation • Research indicates HUMAN MOVEMENT and TRADE are the most common sources of viral transmission
Highly Pathogenic Avian Influenza • Bird to Human Transmission – Rare – Usually a result of very close contact with infected poultry and infected blood/tissues or contaminated surfaces • Human to Human Transmission – Isolated instances suspected (Thailand, 2004) – No sustained human to human transmission to date
H 5 N 1 Distribution • Poultry: – H 5 N 1 in domestic poultry in Asia, Africa, Pacific, Europe and Near East – Considered endemic in parts of Asia and Africa – >240 million bird deaths – H 5 N 1 case mortality rate in domestic poultry: 90 -100% in 48 hours • Humans: – H 5 N 1 confirmed cases in Asia, Africa, and Near East – 2003 -2008: 378 cases; 238 deaths – Case mortality in humans ~ 60%
H 5 N 1 Influenza Avian Case Distribution
H 5 N 1 Influenza Avian Case Distribution
H 5 N 1 Influenza Human Case Distribution
H 5 N 1 in Africa • February 2006, H 5 N 1 first identified in commercial poultry in Africa (Nigeria and Egypt) • April 2007, H 5 N 1 identified in Ghana and Togo Poultry Wild birds Captive Birds Humans FAO Countries with H 5 N 1 presence in birds (as of Sept. 2007)
Poultry Density and CIRAD Wild Duck Telemetry Locations in Africa as of June 30, 2008 CIRAD
H 5 N 1 & East Africa • Currently H 5 N 1 + – – Egypt Djibouti Sudan Somalia (? ) • Currently H 5 N 1 Free – – Kenya Tanzania Uganda Ethiopia • Risks: – Introduction to HPAI “free” countries via poultry trade, human movement, migratory birds • Prevention: – Active, ongoing monitoring & surveillance – Trade restrictions with positive countries – Bolstered inspection at ports of entry – Emergency preparedness and response plans ready to be mobilized
Kenya Red Cross Rift Valley Falls Along Europe/Southern Africa Migratory Route Peak Migration: Mid September - Mid November
HPAI & Poultry Consumption • Loss of Domestic Poultry – Poultry illness/loss of productivity – Poultry death – Poultry culls Kenya: 30 million chickens, 80% raised traditionally by small holders; 2 -3 chickens/rural household Tanzania: 27 million chickens, 70% raised traditionally by small holders Irrational Poultry Consumption Fears • Loss of income – Inability to pay for school fees, medicine, dietary staples • Loss of protein nutrition
FAO/C. Squarzoni
Impacts on Biodiversity Conservation • Threats: – Health of wild birds • May 2005, Qinghai Lake National Nature Reserve (China) H 5 N 1 outbreak; estimates of 5 -10% of world’s population of Bar-headed Geese (Anser indicus) succumbed to AI virus – Communities may turn to bush meat for protein requirements – Fear may incite wild bird culls or wetlands/nesting area destruction
Biodiversity Conservation Opportunities • Accurate information dissemination is essential – Targeting local communities, park staff, media and human & animal health workers • Sound, science-based policy decisions • Wetlands and protected area preservation – Will help limit number of displaced wild birds forced into contact with humans and domestic poultry
Alternative Protein Sources • Communities should be prepared to draw on alternative protein sources to hedge against catastrophic poultry loss • Diversified, Site. Appropriate Livestock Portfolio MEAT Cattle DAIRY Buffalo Cattle Pig Sheep Goat Fish PROTEIN RICH VEGETABLE Peanut Soy
Avian Influenza Preparedness & Response • Surveillance • Communication & Education • Diagnostic Capacity & Commodity Distribution • Research • Rapid Response & Containment
Surveillance • Early detection is critical for containment • Transparent reporting • Donor resources need to be made available for active surveillance • CDC’s Global Disease Detection Center (Kenya) • Army Medical Research Unit (Kenya) International Scientific Task Force on Avian Influenza
Wild Bird Global Avian Influenza Network for Surveillance (GAINS) • Program managed by Wildlife Conservation Society, funded by USAID • Global surveillance & monitoring system – Applicable to other diseases, including wildlife disease • Sharing of near real-time HPAI monitoring in wild birds using an accessible online format • Tracks genetic changes in the virus • Encourages transparent disease reporting – Technical support to national laboratories/vet services for surveillance and diagnostic activities
Global Avian Influenza Network for Surveillance • Target Audiences: – – Government Local Communities Policy Makers Private Sector • Informs decision making to cope with threat of HPAI at local through national levels • Serves as an early warning system for HPAI emergence • Potential to limit risks to human health, wildlife health, & domestic poultry/livelihoods
Global Avian Influenza Network for Surveillance GAINS Global Surveillance Locations Wild Bird Flyways • Upcoming work will use sat transmitters to define the Nile. Rift Valley flyway
Parameters • Dates • Positive Cases • Location • Total Sampled Cases • Wild Bird Species • H & N type • Pathogenicity WISDOM Map Explorer Data • Wild Bird Counts
Communication & Education • Prevention Strategies • Recognizing Illness • Discouraging Consumption of Sick Poultry • Farm/Village Biosecurity • Slaughter and Cooking Precautions • Behavior Change Communication (i. e. hand washing, personal hygiene)
Communication & Education • Preventing Wild Bird Poultry Transmission: • Domestic poultry should not be permitted to commingle with wild birds – Care taken to avoid shared water sources – Fencing or covered sheds – Improved husbandry practices (All In-All Out) • Biosecurity on farms, in households, at markets, and during transport
Communication & Education • Enforcement of the illicit wild bird trade CDC
Diagnostic Capacity & Commodity Distribution • Personal Protective Equipment – Goggles, Aprons, Gloves, Boots • Diagnostic Kits/Reagents • Capacity Building for National Laboratory Diagnosis & Epidemiological Surveillance • Response Preparation: DAI – Disinfectants, etc… Synbiotics
Research • Wild Birds – Can we clarify their role in transmission? – Migratory flyways need to be defined – Which species may be inapparent carriers? Do some species exhibit high mortality rates? – Banding, bird counts, telemetry • Disease Ecology – How persistent is the virus in the environment?
FAO
FAO
Research & Development • Vaccination – Poultry: • Vaccine available; policy on use varies by nation • Reduced morbidity and mortality, however viral shedding still possible in vaccinated poultry – Human: • April 2007, US FDA approved H 5 N 1 human vaccine (Sanofi Pasteur, Inc. ) • Emergency stockpiles only; not commercially available • Future pandemic influenza strain unknown, so vaccine efficacy questionable
Response & Containment • Emergency response plans in place • Centrally coordinated effort drawing on diverse stakeholders • Table and field-tested plans • Adequate resources for culling and disposal • Compensation plans fair, transparent, and fully funded FAO
Additional Resources • News & Updated Information: • CIDRAP www. cidrap. umn. edu • Pro. MED Mail www. promedmail. org • Centers for Disease Control and Prevention www. cdc. gov
Additional Resources • Multi and Bilateral Efforts: • United States Agency for International Development www. usaid. gov • World Health Organization www. who. int • UN, Food and Agriculture Organization http: //www. fao. org/avianflu/en/index. html – Including OFFLU and EMPRES • World Organization for Animal Health http: //www. oie. int/eng/info_ev/en_AI_avianinflue nza. htm
Additional Resources • Monitoring & Surveillance: • Global Avian Influenza Network for Surveillance (WCS) www. gains. org • Educational & Communication Resources: • Inter. Action http: //www. interaction. org/disaster/avian/index. html • Academy for Educational Development http: //avianflu. aed. org/index. htm
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