How serious is the threat of an Avian flu Human Pandemic Avian (Bird) December 2005

Avian Flu  Virus  Bacteria  Infection  Mutation  Carrier of infection  Resistance to infection  Spread of infection  Genetic material General Background Terms

Avian Flu Historical Development Influenza Virus (worldwide problem) Types A-B-C Types A-B-C “HN” Classification of virus (lab testing) “HN” Classification of virus (lab testing)  Hemagglutinin  Neuraminidase 1918 “Spanish” Flu (H 1 N 1 ) 1918 “Spanish” Flu (H 1 N 1 )  Killed 50 million people worldwide 1961 H 5 N 1 found in wild birds in South Africa 1961 H 5 N 1 found in wild birds in South Africa 1997 H 5 N 1 found in Hong Kong 1997 H 5 N 1 found in Hong Kong 2003 Bird Flu re-emergence in South Asia 2003 Bird Flu re-emergence in South Asia

Avian Flu Mechanism of Non-Human Spread  Once spread from wild bird population to domestic birds (Chickens): a first serious step has occurred  A viral “jump” to more domestic animals (horses, cats, pigs): a second serious step will have occurred  This broad “mixing pot” of genetic material; makes the spread to humans more likely from such a pool of replicating gene fragments

Avian Flu Isolated Facts New H 5 N 1 virus comes from mostly avian gene pool (not New H 5 N 1 virus comes from mostly avian gene pool (not mammals) like the H 1 N 1 Spanish flu did (1918) mammals) like the H 1 N 1 Spanish flu did (1918)  Why has it now become lethal in some humans? Unknown!  H 5 N 1 virus remain “alive” in feces, oral droppings, contaminated water for 7-10 days  Asian human H 5 N 1 infections are in younger population (17-31yrs)  In south Asia, human infection has mostly involved direct, close contact with infected birds (blood, feces, feathers)

Avian Flu Isolated Facts Cont’d  Current human Influenza A vaccine does not protect against H 5 N 1 Flu; eating “cooked” infected chickens will not cause infection Flu; eating “cooked” infected chickens will not cause infection  Domestic ducks can carry H 5 N 1 “silently”: so a reservoir for potential carrier of infection  Domestic chickens get “infected” from contact with shed droppings from “migratory waterfowl/ducks” The H 5 N 1 avian flu is 32 times more infective than SARS Virus (2003)

Avian Flu Human Pandemic Requires:  Highly virulent organism  Lack of sufficient human immunity  Easy spread from human to human This is currently absent This is currently absent

Avian Flu Potential Catastrophic Change H 5 N 1 Virus Invades Human Cell Replicates Organ Damage Invades Other Cells Lung Lung Heart Heart Kidney Kidney “Mutates”

Avian Flu Human Diagnosis  Spot testing  Local Labs  Reference Labs (CDC)  Physicians/Hospitals

Avian Flu Initial  High fever  Chest pain  Cough  Weakness, muscle aches  Easy bleeding  Diarrhea Late  Pneumonia  Encephalitis  Kidney failure Human signs and Symptoms Currently in East Asia : mortality 50 % (n=150 cases)

Avian Flu Current Spread of Avian Disease (Asia to Europe) North to Mongolia/Siberia North to Mongolia/Siberia East Asia West to Ukraine, Croatia, West to Ukraine, Croatia, Turkey Turkey

Avian Flu TreatmentSurveillance  China may be Ground Zero (1 st line of defense) 1.3 billion people 1.3 billion people 13 billion birds 13 billion birds 75% of population live on farms 75% of population live on farms Medical system weak Medical system weak  Prophylaxis (For Chickens) Twice a year vaccines Twice a year vaccines  Bird Flu Outbreak Authorities kill hundreds of thousands of birds Authorities kill hundreds of thousands of birds

Avian Flu Human Treatment Quarantine Quarantine  World health Organization (WHO) 21 days to “control” 21 days to “control”  Before disease affects people  Hard for doctor to diagnosis quickly/implement isolation  Area may be as large as a city

Avian Flu Human Treatment Vaccine Vaccine Available for bird now Available for bird now In development for human In development for human Problems with application Problems with application  New mutation may limit effectiveness Antivirals Antivirals Tamiflu (oral) Tamiflu (oral) Relenza (inhalation) Relenza (inhalation) Problems with application of these meds Problems with application of these meds  Not thoroughly tested  Resistance occurs  Stockpilling can be disruptive

Avian Flu Possible Global Threat (Worst case scenario)  Estimate 150 million human deaths worldwide  Estimate economic cost : 800 billion dollars  Theoretical terrorist operation: steal deadly viral genome steal deadly viral genome harvest “live” virus in lab harvest “live” virus in lab deliver as aerosol to unsuspecting populace deliver as aerosol to unsuspecting populace

Avian Flu Conclusions Far-reaching spread of deadly virus to USA (Unlikely) Far-reaching spread of deadly virus to USA (Unlikely) Danger of H 5 N 1 reaching USA is real Danger of H 5 N 1 reaching USA is real Interconnected world (infection carriers) Interconnected world (infection carriers) Wild birds (could first reach Alaska & Canada) Wild birds (could first reach Alaska & Canada) Human travelers (a flight away) Human travelers (a flight away) No intervention has been successful stopping a pandemic once it starts

Avian Flu Conclusions Surveillance, global cooperation, vaccination, antiviral agents,quarantine, infected chicken elimination will prevent epidemic spread in USA Surveillance, global cooperation, vaccination, antiviral agents,quarantine, infected chicken elimination will prevent epidemic spread in USA Gene Mutation and Viral human to human spread is random and cannot be controlled Gene Mutation and Viral human to human spread is random and cannot be controlled SO SO viral illnesses are a stark reality we have to fight viral illnesses are a stark reality we have to fight