Pandemic Influenza: What Is It and Why Should We Care? Dr. Judith A. Monroe, MD State Health Commissioner

What is Influenza?  Viral respiratory illness that occurs usually during the winter months  Spread by droplets from coughing or sneezing, then touching eyes, nose or mouth  Symptoms –fever, chills, cough, sore throat, muscle aches –begin about 1-4 days after exposure  May lead to pneumonia or respiratory distress –elderly –young –weakened immune systems

Influenza Viruses  Type A –Infects humans and animals (such as birds and pigs) –Capable of major genetic changes resulting in new virus subtypes –Most severe illness  Type B –Infects only humans –Less severe illness –Minor genetic changes

What is a Pandemic?  Pandemic = worldwide epidemic  Occurs randomly, but usually decades apart  Most or all of the world’s population lack preexisting immunity to pandemic virus  Spread of infection and severity of illness would likely be much greater than during the annual influenza season  Unlike typical influenza every winter, pandemic influenza is not seasonal

Recipe for a Pandemic  Starts with a new virus subtype –H5N1 avian (bird) flu virus in Europe, Asia, Africa  Causes severe infection –Infection is severe and can be fatal  Efficiently transmits from human to human –Not yet observed

Impact of Pandemic Influenza  Spreads rapidly throughout the world  High morbidity  Excess mortality  Significant burden on medical system  Social and economic disruption

Pandemic  1918 “Spanish Flu” first and worst in twentieth century (H1N1)  US deaths: 500,000  Worldwide deaths: –40 million from the flu –8.5 million from WWI

Other Pandemics  Asian Flu (H2N2) –US deaths: 60,000 –Global deaths: 1 million  Hong Kong Flu (H3N2) –US deaths: 40,000 –Some immunity from  All three pandemics had a huge social and economic impact

Current Situation: H5N1  Reservoir in water birds (ducks, geese, swans)  Highly lethal in poultry –~ 100% death rate within 48 hours  December 23, 2003—February 27, 2006 –169 confirmed human cases, 91 deaths –54% death rate among known cases –virtually all cases related to contact with infected poultry –suspected but not proven human-to-human transmission

Contact With Poultry In Eurasia  Farming practices much different than in U.S. –Poultry housed in same areas as humans –Allowed to roam freely, exposure to infected wild birds  Consumption of sick, dead birds  Ill birds marketed in crowded marketplaces and sold/transported, often illegally  H5N1 not yet found in U.S. –Federal/state agencies testing wild birds for H5N1 –Poultry industry testing every lot of poultry for slaughter

Impact Estimates for U.S. Pandemic Deaths thousand % Hospitalizations thousand % Outpatient care18-42 million 6-15% Total infected million 15-35%

Medical Management  Vaccine – will require 6-8 months to develop against a pandemic strain  Antivirals – some may be effective against a pandemic strain but supply likely limited

Trigger The trigger to enact preparedness plans is sustained human-to-human transmission anywhere in the world

Challenges  Widespread: pandemic will likely occur everywhere almost simultaneously  Long-term: successive waves may last a year or more  Essential services will have to be maintained with as much as 1/3 of the workforce out sick at any one time

Take Home Message  Local response will be critical: not much state or federal support available  Need to partner and plan NOW  Purpose of today’s summit