Avian Influenza What does it all mean Important

Avian Influenza – What does it all mean? Important Background Information Island Paravets and Residents

Avian Influenza: Background n n Waterbirds are the natural reservoir of all Influenza “A” viruses. Wild birds and these diseases have evolved together naturally over time Many subtypes of AI already exist in wild bird populations in North America – but currently not HPAI H 5 N 1

Avian Influenza: Background Influenza strains are named for their specific types of protein spikes that act as a “lock and key” mechanism with host cells H = hemagglutinin (16 types) N = neuraminidase (9 types) H 5 N 1 Source: Horimoto and Kawaoka, 2005. is one of the 144 possible combinations. One subtype (HPAI H 5 N 1) is of concern worldwide.

Avian Influenza: Background n Pathogenicity refers to the ability of the virus to produce disease and is based on the impacts to domestic poultry n n Low pathogenic = few clinical signs, mostly respiratory and digestive problems High pathogenic = attack many organs, can cause high mortality HPAI = kills >75% of chickens AI viruses can become very pathogenic when they enter a new host (domestic poultry, humans, some carnivores). This is the suspected origin of HPAI strains.

Avian Influenza: Background Significant Variation within current HPAI H 5 N 1 subtypes n n n Juvenile mallards were inoculated with 23 different isolates of HPAI H 5 N 1 Results ranged from no clinical signs (n=8 virus isolates) to high lethality in inoculated ducklings 22/23 virus isolates were efficiently transmitted from inoculated ducklings to susceptible contacts Sturm-Ramirez et al. 2005

Avian Influenza: Background Why are we so worried about “bird flu”? n n HPAI H 5 N 1 is spreading rapidly across the globe HPAI H 5 N 1 has killed 132 out of 230 people infected (57%) If avian influenza combines genetically with human influenza it can become very infectious among humans The risk of H 5 N 1 changing to become global pandemic influenza is unknown

Avian Influenza: Background

Avian Influenza: Current Situation HPAI H 5 N 1 Human cases Dec. 2003 to May 2006 Country Indonesia Thailand Vietnam Cases 32 22 93 147 Deaths Population 24 14 42 80 207 million 65 million 84 million 356 million Average = 1 case per 2. 4 million people Average = 1 death per 4. 5 million people

Avian Influenza: Current Situation Compared to 230 human cases of HPAI H 5 N 1 worldwide in nearly a decade…. . Each year in the U. S. 5 -20% of the population will get HUMAN seasonal flu § > 200, 000 people hospitalized § ~ 36, 000 people die

Avian Influenza: Current Situation Almost all human infections have resulted from direct contact w/ live or dead domestic poultry

Avian Influenza: Current Situation How could HPAI H 5 N 1 reach islands ? Infected People Commercial /Illegal Trade of Birds, Poultry Meat, Eggs Wild Birds

Efforts to “stamp out” HPAI H 5 N 1 in Asia and Europe proving to be difficult n n Culling infected flocks Quarantine infected areas Enclosing poultry operations Vaccinating birds

Avian Influenza: What You Should Know n n n Reporting mortalities -> Culling -> Loss of income unless governments compensate farmers for culled poultry Compensation for flocks is essential for accurate reporting Sale or slaughter of sick birds is known to spread HPAI in Asia

Avian Influenza: What is Your Role? n n n Be “eyes and ears” of animal health authorities Keep informed about AI via the internet Become connected with those on- and off -island who will make decisions about responding to HPAI Know how to respond appropriately Communicate effectively with the public and government about risks and realities of HPAI H 5 N 1