Pandemic H1N1 Influenza:The California Experience

Pandemic Influenza Summit II San Bernardino County Department of Public Health

July 15, 2009

Pandemic Influenza Plan

• Lengthy and detailed but no operational component

• Assumptions: – Phase 6 Pandemic– Avian influenza model

• H5N1 Avian Influenza virus• Person-to-person transmission• 1-2% fatality rate• 30-40% attack rate• Antiviral susceptibility

Seasonal flu vs. Pandemic flu

Seasonal Flu• Occurs every year, usually in

winter, in temperate climates

• Usually some immunity built up from previous exposure

• Healthy adults usually not at risk for serious complications

• Vaccine for seasonal flu is based on known virus strains

Pandemic Flu• Occur sporadically throughout

history – 2-3 waves of 3-4 months- total duration up to 18 months

• Little or no pre-existing immunity

• Healthy people of all age groups may be at risk

• Vaccine probably will not be available in the early stages of a pandemic

Baseline Assumptions at Onset of Pandemic H1N1, April 2009

• Novel H1N1 with swine, avian and human components never before seen in the world

• Since novel, assume no one is immune• Potentially as severe as Avian Flu or

1918• Since no direct swine contact, assume

person-to-person spread• Mexico reported exacerbation of influenza

with many deaths. Due to swine flu?

California Pandemic H1N1 Response - Chapter 1

• Joint Emergency Operation and Richmond Coordinating Center Activation– Daily local, state and federal conference calls– Healthcare Alerts and Guidance created– Daily media briefings

• Aggressive Response Actions– Governor Proclamation of Public Health Emergency– Enhanced surveillance recommended statewide– Teams deployed to the field– Emergency purchase of lab equipment/reagents for 24

local and state public health laboratories – Swine Flu Hotline activated – Antiviral stockpiles deployed to LHDs

Key Aspects of California’s Response – Chapter 1

• Partnership between CDPH and LHD• Richmond Emergency Coordinating Center• Sentinel Physician Surveillance• Laboratory Regional Network (LRN)• VRDL• Field response• Response, calibrated to severity

– Novel virus, yet mostly non-severe illnesses

• Media and public reaction tempered

Trust for America’s Health Report

Lessons Learned – Chapter 1

• Investments in pandemic planning and stockpiling antiviral medications paid off;

• Public health departments did not have enough resources to carry out plans;

• Response plans must be adaptable and science-driven;

• Providing clear, straightforward information to the public was essential for allaying fears and building trust;

• School closings have major ramifications for students, parents and employers;

Trust for America’s Health Report

Lessons Learned, Chapter - 1, cont. • Sick leave and policies for limiting mass

gatherings were also problematic; • Even with a mild outbreak, the health care

delivery system was overwhelmed; • Communication between the public health

system and health providers was not well coordinated;

• WHO pandemic alert phases caused confusion; and

• International coordination was more complicated than expected.

Trust for America’s Health Report

Systemic Gaps – Chapter 1 • Maintaining the Strategic National Stockpile• Vaccine development, production, and distribution• Vaccinating all Americans • Planning and coordination • School closings, sick leave, and community mitigation

strategies• Global coordination• Resources• Workforce• Surge capacity• Health care for uninsured and under-insured

Public Health ResponseChapter 2

How many cases of H1N1 infection have occurred in California as of last week?

A. 224,690B. 24,690C. 2,469D. 246E. None of the aboveF. It does not matter

Public Health ResponseChapter 2

California (San Bernardino Co) Pandemic H1N1 infections as of 7/9/2009

• Total Cases: 2,469 (139)

• Confirmed: 1,945 (134)

• Hospitalizations: 287 ( 15)

• Deaths: 32 ( 1)

Pandemic A (H1N1) 2009 Virus Infections in California Hospitalized and Fatal Cases by Date of Symptom Onset

Current as of July 8, 2009

0

2

4

6

8

10

12

14

16

4/1/20094/3/20094/5/20094/7/20094/9/20094/11/20094/13/20094/15/20094/17/20094/19/20094/21/20094/23/20094/25/20094/27/20094/29/2009

5/1/20095/3/20095/5/20095/7/20095/9/20095/11/20095/13/20095/15/20095/17/20095/19/20095/21/20095/23/20095/25/20095/27/20095/29/20095/31/2009

6/2/20096/4/20096/6/20096/8/20096/10/20096/12/20096/14/20096/16/20096/18/20096/20/20096/22/20096/24/20096/26/20096/28/20096/30/2009

Date of Symptom Onset

Number of Cases

Died Survived

California Pandemic (H1N1) cases by County, July 9, 2009

California Pandemic (H1N1) cases by Age, July 9, 2009

Percent

<1 2.3

1-9 20.2

10-19 35.0

20-34 23.0

35-49 11.5

50-64 6.4

65+ 1.7

Median age: 17.0 years

Age group, in years (of those cases with data)

California Pandemic (H1N1) Virus Infections Number of Confirmed and Probable Cases by Reported Race/EthnicityCurrent as of July 9, 2009 (based on cases with race/ethnicity reported)

612

360

73

158

13

0

100

200

300

400

500

600

700

Hispanic White Black API Amer Indian

Reported Race/Ethnicity

Number of cases

Public Health ResponseChapter 2

• The problem is far from over• Epidemiologic questions:

– Ease of transmission?– Risk populations?– Virulence factors?– Severity?– Protective and risk factors?

• Laboratory capacity– Ongoing testing, high volume– H1N1 genome changes?

• Ongoing cluster and outbreak response• PH worker and HC provider safety• Vaccine production and distribution

H1N1 Vaccination Program Planning Assumptions

• Configuration in each state and local jurisdiction determined by the target population

• Limited amount of vaccine available initially• Vaccine might be adminstered in diverse settings • Severity of illness is unchanged from what has already

been observed • Risk groups affected by this virus do not change

significantly • Vaccine testing suggests safe and efficacious product • Adequate supplies of vaccine can be produced • No major antigenic changes are evident that would

signal the lack of likely efficacy of the vaccines being produced

H1N1 Vaccination Program Planning Scenario 1

• Target population:  – Students and staff (all ages) associated with schools

(K-12th grade) and children (age ≥6 months) and staff (all ages) in child care centers

• Primary vaccination venues:  – schools and child care centers

• Goals: – Provide direct protection against illness among

persons who have high attack rates of illness, reduce likelihood of outbreaks that may lead to disruptive school dismissals, reduce transmission from schools into homes and the community

H1N1 Vaccination Program Planning Scenario 2

• Target population: – Pregnant women, children 6 months – 4 years of

age, new parents and household contacts of children <6 months of age.

• Primary venues: – Provider offices, community clinics

• Goal: – Reduce complications of novel H1N1 influenza

among those vulnerable for serious complications of influenza; protect the youngest (<6 months) who are not themselves able to be vaccinated through immunization of their household contacts

H1N1 Vaccination Program Planning Scenario 3

• Target population: – Non-elderly adults (age <65 years) with medical

conditions that increase the risk of complications of influenza

• Primary venues: – Occupational settings, community clinics,

pharmacies, providers’ offices • Goal:

– Reduce risk of hospitalizations and deaths among persons with higher rates of these complications than the general population, and focus vaccine where its impact can be most beneficial for direct protection

H1N1 Vaccination Program Planning Scenario 4

• Target population: – Health care workers and emergency services sector

personnel (regardless of age) • Primary venue:

– Occupational settings, providers’ offices• Goal:

– Reduce risk of illness, sustain health system functioning, and reduce absenteeism among front-line providers; reduce transmission from emergency services personnel and health care workers to patients; provide additional worker protection in settings of increased exposure

Summary

• Successful response in chapter one• Pandemic H1N1 still causing morbidity

and mortality in summer months• High likelihood of second more intense

wave in fall• Significant challenges for chapter two• Public health and healthcare systems will

be tested to the limit

Questions - Discussion