Pandemic Influenza Contra Costa Health Services Public Health Division June 2006

Seasonal influenza Pandemic influenza Can history help us see the future? Challenges Where do we go from here? Overview

Respiratory illness characterized by fever, headache, tiredness, dry cough, sore throat, runny nose, muscle aches and occasionally nausea, vomiting and diarrhea Complications occur mostly among “high risk” and include bacterial pneumonia, dehydration, and worsening of chronic conditions such as congestive heart disease, asthma and diabetes Seasonal Influenza

Epidemiology of Influenza Infectivity is relatively high Infectivity is relatively high The incubation period is short The incubation period is short Clinical illness is non-specific Clinical illness is non-specific Ease of transmission Ease of transmission Routes of transmission Common: large droplets (sneezing, coughing, contact with saliva) Common: large droplets (sneezing, coughing, contact with saliva) Common: fomites Common: fomites Rare: airborne over long distance Rare: airborne over long distance

Pandemic Influenza Summary Easily transmitted from person to person Easily transmitted from person to person Highly infectious virus Highly infectious virus Most of population has no experience (immunity) Most of population has no experience (immunity) May also infect animals other than humans May also infect animals other than humans Limited or no vaccine Limited or no vaccine Limited antiviral medications available Limited antiviral medications available Limited excess capacity in health care system Limited excess capacity in health care system

Years FluVirusMortality Years FluVirusMortality “Spanish” Type A (H1N1) 20 million worldwide 550,000 US “Spanish” Type A (H1N1) 20 million worldwide 550,000 US “Asian” Type A (H2N2)70,000 US “Asian” Type A (H2N2)70,000 US “Hong Kong” Type A (H3N2)34,000 US “Hong Kong” Type A (H3N2)34,000 US Glezen WP. Epidemiol Rev. 1996;18:65. Centers for Disease Control and Prevention. Influenza Prevention and Control. Influenza. Available at: Influenza Pandemics in the 20th Century

CDC Estimates of Percent of Population Affected by the Next Pandemic* Number Affected in California (Pop. 36,363,502)** 15% to 35% of pop. will become ill with flu 15% to 35% of pop. will become ill with flu 5.4 – 12.7 Million 5.4 – 12.7 Million 8% to 19% of pop. will require out-patient visits 8% to 19% of pop. will require out-patient visits 2.9 – 6.9 Million 2.9 – 6.9 Million 0.2% to 0.4% of pop. will require hospitalization 0.2% to 0.4% of pop. will require hospitalization 72,000 – 145,000 72,000 – 145, % to 0.1% of pop. will die of flu-related 0.04% to 0.1% of pop. will die of flu-related causes causes 14,000 – 36,000 14,000 – 36,000 Pandemic Influenza Estimates for California *Estimates from FluAid 2.0, CDC www2.cdc.gov/od/fluaid/default.htmwww2.cdc.gov/od/fluaid/default.htm **California Department of Finance Pop. Projections for 2003

Inactivated Influenza Virus Vaccine ContentUpdated yearly to protect against anticipated strains, consists of type A (2) and type B (1) ProcessGrown in chicken eggs and formalin inactivated

Antiviral - Tamiflu Limited supply – single manufacturer for world supply Limited supply – single manufacturer for world supply Expensive Expensive Would need to prioritize who would receive anti-viral medications Would need to prioritize who would receive anti-viral medications

Influenza vs SARS Influenza Influenza SARS SARS Incubation Incubation period period 2-3 days 2-3 days 10 days 10 days Infectivity Infectivity Up to 24 hours before symptoms peak Increases over course of illness Symptoms Symptoms Non-specific symptoms, no well defined risk groups Fever, cough H/O exposure to SARS pt (or setting)

Pandemic Flu - Summary We do not have a virus circulating that could cause a pandemic at this time We do not have a virus circulating that could cause a pandemic at this time The world experiences a pandemic of influenza periodically and not at regular or predictable intervals The world experiences a pandemic of influenza periodically and not at regular or predictable intervals We need to have plans in place to respond in the event of a pandemic to take care of the needs of the people we serve We need to have plans in place to respond in the event of a pandemic to take care of the needs of the people we serve