Avian Influenza H5N1 The Next Pandemic? May 9, 2006

1997 First Human Outbreak  Hong Kong  18 Infected  6 Killed

1997 through February 2004

August 2004

July – August 2005

October 2005

April 27, 2006

How does this affect humans?  Risk of direct infection  Risk of mutation  More infected birds = more opportunities for human infection

Country Total casesdeathscasesdeathscasesdeathscasesdeathscasesdeaths Azerbijan Cambodia China Egypt Indonesia Iraq Thailand Turkey Viet Nam Total Source: World Health Organization 55% Mortality

Country Total casesdeathscasesdeathscasesdeathscasesdeathscasesdeaths Azerbijan Cambodia China Egypt Indonesia Iraq Thailand Turkey Viet Nam Total Source: World Health Organization 55% Mortality

Country Total casesdeathscasesdeathscasesdeathscasesdeathscasesdeaths Azerbijan Cambodia China Egypt Indonesia Iraq Thailand Turkey Viet Nam Total Source: World Health Organization 55% Mortality

Country Total casesdeathscasesdeathscasesdeathscasesdeathscasesdeaths Azerbijan Cambodia China Egypt Indonesia Iraq Thailand Turkey Viet Nam Total Source: World Health Organization 55% Mortality

Country Total casesdeathscasesdeathscasesdeathscasesdeathscasesdeaths Azerbijan Cambodia China Egypt Indonesia Iraq Thailand Turkey Viet Nam Total Source: World Health Organization 55% Mortality

Country Total casesdeathscasesdeathscasesdeathscasesdeathscasesdeaths Azerbijan Cambodia China Egypt Indonesia Iraq Thailand Turkey Viet Nam Total Source: World Health Organization 55% Mortality

Current State  WHO Phase 3 – Self limiting  Human infection with a new subtype, but no human-to human spread, or at most rare instances of spread to a close contact. Even without human intervention it would be self- limiting among humans

Reasons for Concern  H5N1 entrenched in Southeast Asia  Infected poultry and birds in new areas increase opportunities to infect humans and swine  Each human case gives H5N1 an opportunity to improve transmissibility  Each swine case provides an opportunity for mutation

Reasons for Concern  Domestic ducks acting as “silent reservoirs”  H5N1 now lethal to mice and ferrets  H5N1 surviving longer in the environment  H5N1 increasing its host range  Infecting and killing mammalian species previously considered resistant

Treatment  Amantidine  Cheap  Easy to Produce  Oseltmivir (Tamiflu)  More expensive  Difficult to produce in large quantities  Zanimivir (Relenza)  Untested on H5N1  Expected to be an effective treatment

Treatment  Amantidine  Cheap  Easy to Produce  Oseltmivir (Tamiflu)  More expensive  Difficult to produce in large quantities  Zanimivir (Relenza)  Untested on H5N1  Expected to be an effective treatment

Worst Case Scenario  30% Infected in United States  40% of work force absent at peak of pandemic  1.9 million dead

Pandemic Planning

Pandemic Planning - Federal  Stockpile of antiviral treatments  26 million treatment courses  81 million by end of 2008  Enough to treat 25% of US population  Increased funding for vaccine development and production

Pandemic Planning - Social  Quarantine  Only effective at onset of pandemic  Social Distancing  Likely result of widespread pandemic  Increases distance between individuals  School Closures  Business Closures  Staying home when ill  Avoiding large gatherings  Telecommuting

Pandemic Planning - Local  Goals:  Increase the use and development of interventions known to prevent human illness.  Decrease the time needed to detect and report threats to the public health  Decrease the time to identify causes, risk factors, and interventions for those affected.  Decrease the time needed to [provide countermeasures and health guidance to those affected  Improve the timeliness and accuracy of communications regarding threats to the public's health

More Information  United States Information   World Health Organization   World Organization for Animal Health   Center for Infectious Disease Research and Policy 