Robert M. Levin, M.D. Ventura County Department of Public Health The Nature of Influenza

• Humans, and pigs share the • Contagiousness is high and starts before any symptoms • The incubation period is short • Infected people can have no symptoms, mild illness or even die Routes of transmission

• Common: large droplets (sneezing, coughing, contact with saliva) • Common: objects, hands • Rare: airborne over long distance

Requirements for a Pandemic

• Isolation from humans of a new and unique • No immunity in the population • Proven ability of the virus to reproduce and cause disease in humans • Efficient person-to-person spread Influenza in the 20th Century

Years Flu Virus Mortality

1918-1919 “Spanish” H1N1 20 million 550,000 US

1957-1958 “Asian” H2N2 70,000 US

1968-1969 “” H3N2 34,000 US

Glezen WP. Epidemiol Rev. 1996;18:65. Centers for Disease Control and Prevention. Influenza Prevention and Control.

California Department of Health Services Immunization Branch AMERICAN MORTALITY RATES PER 100,000 DUE TO 1918 FLU PANDEMIC

California Department of Health Services Immunization Branch

Infectious Disease Mortality, United States--20th Century

California Department of Health Services Immunization Branch Armstrong, et al. JAMA 1999;281:61-66.

AVIAN H5N1 OUTBREAKS Migration Patterns and Bird Flu Spread

United States

WHO Lab Confirmed Human Cases as of November 1, 2005 Cases Deaths Indonesia 7 4 Vietnam 91 41 20 13 Cambodia 4 4 Total 122 62 Mortality 51% "The situation in Southeast Asia right now is the most significant setup for a very serious public that I've seen in my 30 years in this business. We're sitting on a time bomb."

Dr. Michael Osterholm Director, Center for Infectious Disease Research and Policy, University of Minnesota “Prepare for massive social and economic disruption.”

World Health Organization Pandemic Influenza Estimates for California

Number Affected in CDC Estimates of Percent of Population California Affected by the Next Pandemic* (Pop. 36,363,502)**

15% to 35% of pop. will become ill with flu 5.4 – 12.7 Million

8% to 19% of pop. will require out-patient visits 2.9 – 6.9 Million

0.2% to 0.4% of pop. will require hospitalization 72 – 145 Thousand

0.04% to 0.1% of pop. will die of flu-related causes 14 – 36 Thousand

*Estimates from FluAid 2.0, CDC www2.cdc.gov/od/fluaid/default.htm **California Department of Finance Pop. Projections for 2003 H5N1 (The Avian or Bird Flu Virus) All prerequisites met for start of pandemic except human-to-human transmission

• More of a killer than most avian strains – Progressively more lethal in – Larger number of animal species affected • Ducks have no symptoms but shed virus, so are a reservoir • Pigs shown to be infected in • Human cases concentrated in previously healthy children and young adults MechanismsMechanisms ofof InfluenzaInfluenza VirusVirus AntigenicAntigenic ““ShiftShift””

CT DIRE

Non-human Human virus virus

Reassortant virus Monitoring for avian influenza in wild and domestic birds • The CA Dept of Fish and Game • UC Davis Wildlife Health Center • U.S. Fish and Wildlife Service • CA Dept of Food and Agriculture • CA Dept of Health Services Possible Measures to Control • Measures to reduce risk that cases transmit – Confinement – Face masks (symptomatic, exposed, seeking care) • Measures to reduce risk that contacts transmit infection – Follow-up of contacts – Quarantine of healthy contacts – Antiviral prophylaxis • Measures to increase social distance – Isolation of ill – Closures – Masks Models suggest potential containment of initial clusters using a combination of

• Isolation and Quarantine • Case treatment and contact prophylaxis with antivirals • School and work closure

¾After 4-5 weeks, it will probably be impossible to contain

California Dept of Health Services Immunization Branch Conditions for success of initial control • Rapid identification of initial cluster • Rapid case detection and treatment • Rapid prophylaxis of targeted population – Sufficient drug available – No antiviral resistance • Population cooperation with strategies

California Dept of Health Services Immunization Branch Pandemic stages •0.1: Novel virus subtype isolated from single human case •0.2: >2 human with novel virus – no evidence of person-to-person transmission •0.3: Person-to-person transmission confirmed •1.0: Several outbreaks in at least one country, international spread, severe morbidity and mortality in at least 1 segment of population Possible measures to reduce risk that cases transmit infection

Pre-pandemic Pandemic 0.1-0.2 0.3

– Confinement Y Y Y – Face masks ƒ Symptomatic persons YY Y ƒ Exposed persons CC C ƒ Persons seeking care in Y Y Y risk area

Y: yes, N: No, C: consider Possible measures to reduce risk that contacts transmit infection

Pre-pandemic Pandemic 0.1-0.2 0.3 • Tracing and follow Y Y N up of contacts • Voluntary quarantine of N Y N healthy contacts • Advise contacts to reduce N N N social interaction • Provide contacts with Y Y N antiviral prophylaxis Possible measures to increase social distance

Pre-pandemic Pandemic 0.1-0.2 0.3 • Vol. home confinement Y Y Y of symptomatic persons • Closure of schools N C C • Population-wide measures N C C (e.g. close workplaces) • Masks in public places N N N* Y Yes, N no, C consider * Not known to be effective Pandemic Spread and Availability • Spread of a pandemic – Months to reach U.S. for prior pandemic strains 1918 – 0; 1957 – 4-5; 1968 – 2-3; 1977 – 3-4 – Next pandemic: earlier entry from air travel may be offset by international surveillance • Availability of vaccine – Optimally, first doses available ~4 months after reference strain is developed – Weekly delivery of ~3-5 m doses from U.S. production – Federal guidelines for prioritization Prototype Vaccine

• Hungary has developed and tested on 150 persons • Claims it is effective “beyond doubt” • Set to be approved by European Medicines Agency • Sold at $5-6 per dose • Ready to begin production The Federal Government will develop priority recommendations (11/1/2005) National Vaccination Priority Recommendations* Tier Element # indv

1A • Health care involved in direct patient contact and essential support 9 m • Vaccine and antivirals manufacturing personnel 40 K 1B • Highest risk group 26 m 1C • Household contacts of children <6 months and severely immune 11 m compromised, and pregnant women

1D • Key government leaders and critical public health responders 151 K

2 • Remainder of high risk group 60 m • Other public health responders and infrastructure personnel 8.5 m 3 • Other key government health decision makers and mortuary services 500 K

4 • Healthy 2-64 years not in other groups 180 m

*Approved by NVAC/ACIP committee on July 19, 2005

Antiviral Stockpile ()

Recommedations of Advisory Group • 40 million courses minimum – 133 million courses to treat all infected and prophylaxis HCWs and patients at highest risk of infection Surge Capacity

• Beds – Emergency regulations, increase in beds in existing facilities, alternative facilities, tents, home care • Personnel – Emergency System for Advance Registration of Volunteer Health Professionals (ESAR-VIP); Medical Reserve Corps; citizen volunteers; scope of practice changes • Equipment – SNS; HRSA grant Coercive public health action must be: • Effective • Necessary • The least restrictive means • Proportional • Impartial

Kayman: Albany School Public Health Presentation Aug 2005 Ethics of Emergency Response

Tension between • Individual rights and freedoms • “Common good” and the public’s health Why do we feel so anxious about this threat?

Because usually, the government protects us.

This time, we must rely on many small defenses, some quite old-fashioned. This time, we must take personal responsibility. We must defend ourselves. This time, we must accept that “doing everything” only decreases our vulnerability, but won’t make us invulnerable. Summary Summary of our County’s Planning Efforts • We have a pandemic flu plan which we have submitted to the State; • We have done some and are planning additional "exercises" to practice our pandemic flu response; • We are in immediate contact with the state for the purpose of letting us know if there is any imminent threat from a "new" mutated avian flu virus; • We have increased the public health lab's ability to both grow and rapidly identify flu viruses from patients in our county; • Our communicable disease reporting system lets us know when there are seriously ill patients with bad respiratory disease in any of our hospitals so that we might follow up on them on the chance that they might have the bird flu; Summary - Continued • We have one and we are trying to recruit three more "sentinel" physicians who serve as medical practices that look for and track patients with the flu; • We have a team of epidemiology investigators, and we are training more, who are able to interview and isolate the contacts of cases of pandemic flu when they occur in our county; • We have already recorded (and KVTA is playing) 9 PSA's about the bird flu; • We have researched and are ordering the most protective facemasks available to protect our nurses and patients associated with avian flu cases; • Orders related to public gatherings will be considered and acted upon depending on the stage of a pandemic; Summary - Continued • People will be told to stay home from work or school if they feel ill; • Messages concerning the importance and effectiveness of hand washing and using tissues will be disseminated before and with the first case of bird flu; • Depending on the availability of Tamiflu, we will be following federal guidance as to its recommended usage; the same can be said for any flu that become available; • Quarantine at home will be utilized for many sick people in our county; • Travel restrictions from areas with cases of avian influenza can be anticipated to be in force early in a pandemic; • The Ventura County Public Health DOC will be opened upon hearing of the appearance of pandemic flu anywhere in the world; • Model PSA's and news releases are being drawn up in anticipation of a pandemic flu. WHAT DO WE HAVE GOING FOR US? • A mutated virus may turn out to be not as dangerous as we fear. • The vaccine being developed now may be more effective than we expect. • The pandemic may occur in two waves and give us time to develop a specific vaccine. • The may not occur for years, giving us time to develop large supplies of Tamiflu. • We have much better supportive health care today than in 1918. • We are healthier as a people today than in 1918. • We have antibiotics today to treat secondary bacterial infections. • The Avian flu virus has not mutated yet and may never do so.