the h1n1 influenza pandemic kentucky optometric association september 8, 2009 kraig e. humbaugh,...

The H1N1 Influenza Pandemic

Kentucky Optometric AssociationSeptember 8, 2009

Kraig E. Humbaugh, M.D., M.P.H.Kentucky Department for Public Health

Cabinet for Health and Family Services

What is a Pandemic?

• Pandemic = Global Epidemic• An epidemic (or outbreak) occurs when more

than the usual number of expected cases occurs

• An influenza pandemic results when a new strain of influenza that the living human population is not immune to begins circulating human-to-human


Why Do influenza Pandemics Occur?

• Influenza is a very changeable virus• Minor genetic changes occur from season to

season• When major changes occur,

a new pandemic strain

can emerge


How Humans Spread the Flu

• Droplet or contact spread• Infectious period

– Adults: 1 day prior to symptoms to about 5 days after onset

– Young children and immunocompromised, much longer

• Incubation period– 1 to 4 days Image Source: Human Biology, Starr and McMillan


Children/Teenagers 29%

Adults 59%

Seniors 12%

Demographics

Glass, RJ, et al. Local mitigation strategies for pandemic influenza. NISAC, SAND Number: 2005-7955J

School

Household

Workplace

Likely sites of transmission

Who Infects Whom?

To Children To Teenagers To Adults To Seniors Total From

From Children 21.4 3.0 17.4 1.6 43.4

From Teenagers 2.4 10.4 8.5 0.7 21.9

From Adults 4.6 3.1 22.4 1.8 31.8

From Seniors 0.2 0.1 0.8 1.7 2.8

Total To 28.6 16.6 49.0 5.7


Seasonal Influenza: A Yearly Threat

• About 200,000 hospitalized each year and about 36,000 die annually in US of influenza and its complications

• Seasonal influenza vaccine is expected to be readily available this year

• Almost anyone 6 months and older who wants protection from influenza infection or wants to prevent transmission can get a flu vaccination


Novel H1N1: the New Pandemic Strain• H1N1 influenza: first recognized in Mexico in

April 2009• World Health Organization: pandemic phase

6 declared on June 11, 2009• Centers for Disease Control and Prevention

(CDC) estimates over 1 million infections in the U.S., most unconfirmed. 8,000 hospitalizations and 500 deaths nationally.

• CDC has ceased counting individual cases


Compare & Contrast: H1N1 vs. Seasonal

• Similar mechanism of spread• Comparable severity of illness• Attack rate for H1N1 likely higher, because

more of the population is susceptible• Incidence of H1N1 infection highest in children• Incidence of H1N1 infection lowest in seniors• More complications for illness in pregnant

women and those with chronic diseases• Similar public health strategies


KY’s H1N1 Snapshot: Sept. 2009• Almost all influenza this summer has been

H1N1, per statewide surveillance and testing at KDPH’s Division of Laboratory Services

• Outbreaks in schools, correctional facilities and other institutional residential settings

• Progression from containment to mitigation phase, due to sustained persistence of human-to-human transmission

• Transition from individual case reporting to reporting by statewideactivity level


KY: Regional Flu Activity in Summer!


Worst Case Scenarios• Attack rate of 20-40% (40% of the population ill,

probably in waves weeks to months apart)• Virulence of H1N1 virus increases, so that severity is

greater than seasonal influenza• H1N1 virus becomes resistant to antiviral medicines• Kentucky Health Projections:

– Deaths: 3000 – 7000– Hospitalizations: 9,200 – 21,400– Outpatient visits: 455,000 – 1.06 million

• Kentucky Economic Projections:– Infrastructure: Thousands at home either ill or caring for ill– Potential economic losses in the billions $$$


Mortality rate by age: 1918 pandemic


1918 Pandemic 2nd and 3rd waves 13


Pandemic Influenza Planning: Global Epidemic-Local Response

• Kentucky Emergency Management: Lead agency for all hazards

• State pandemic influenza plan since 2003, updated in April 2007 and July 2008, with input from multidisciplinary stakeholder group

• 50 community-based summits sponsored by local health departments held throughout the commonwealth in summer 2006

• Each local health department planning; communities should prepare to be self-sufficient


Public Health Strategies

3 Public Health strategies for successfully responding to an influenza pandemic:–Antiviral medicines –Vaccine–Behavioral interventions that decrease

spread• Individual health behaviors• Community-based mitigation interventions,

such as “social distancing,” and other activities


Antivirals: Treatment for Flu• Antiviral medicines do not “cure” the flu, but

help to lessen flu’s severity and course• To be effective, antivirals should be given

ASAP after first symptoms develop• Antivirals are available in limited supply,

though supply is increasing• H1N1 appears to be susceptible to

oseltamivir (Tamiflu) and zanamivir (Relenza), so far

• Gov’t-purchased antivirals can be used if commercial supplies depleted


Clinician Guidance

• Most patients will not need testing or treatment while H1N1 severity remains comparable to seasonal flu

• Consider treating with antivirals high-risk patients with flu-like symptoms and those asymptomatic high-risk household contacts of ill patients (young children, pregnant women, health care workers)


Novel H1N1 Vaccine• Expected to be available from the federal

government through public health in the fall• Public & private partnership needed for

vaccine coverage• Demand could exceed supply, necessitating

the limitation of first shipments to target groups

• Delivery will be complicated by simultaneous administration of seasonal flu vaccine

• 2 doses likely required for immunity


H1N1 Vaccine Target Groups

• Target Groups, when vaccine becomes available:– pregnant women– household contacts and caregivers of children <6 mos.– health care workers– persons 6 mos.-24 years – persons 25-64 yrs. w/ a chronic medical condition

• Priority Groups, if limited vaccine availability: – pregnant women– health care workers with direct patient contact– household contacts and caregivers of children <6 mos.– children 6 mos.- 4 years – children 5-18 yrs. w/ a chronic medical condition


Vaccine Distribution• Vaccine allotment to KY determined by

population• Determination of KY’s jurisdictional allotment

by state health department• Determination of vaccine shipments to

providers by local health departments• Vaccine shipments through centralized federal

system directly to providers• Prioritization of providers serving target pop.’s• Ancillary vaccine supplies sent separately


Provider Participation

• Enrollment through https://khelps.chfs.ky.gov/• Public and private providers are needed to

vaccinate• Providers will be requirement to sign a

provider agreement with Public Health• Providers will be able to charge for vaccine

administration, but not for the vaccine itself


H1N1 Vaccine Demand

Unknown ???

Likely a function of:• Perceived Safety of Vaccine

versus • Severity of Illness


Behavioral InterventionsPromoting barriers to spread, from individual

level to community:• Hand washing• Personal Protective Equipment (masks, etc..)

for health care workers• Isolation and treatment of ill persons at home,

when feasible• Dismissal of students from school and

employees from work: social distancing Targeted Layered Containment (TLC):

The sum of various strategies is likely to be greater than the parts.


How every Kentuckian can prepare. . .

• Wash hands frequently• Cough / sneeze into tissue or elbows• Avoid crowds during outbreaks• If sick, stay home from work / school• Develop an “all hazards” emergency

preparedness family plan and kit• Get a seasonal flu immunization each fall

Advice for both seasonal and pandemic influenza


Handwashing!

The scientific evidence supports the conclusion that handwashing helps to decrease respiratory infections.

Alcohol-based hand gels can be an effective alternative to handwashing, but only if the hands are not visibly soiled.


Handwashing

According to a 2007 study done by the American Society for Microbiology:

• Only about three-quarters of adults were observed to have washed their hands after using public restrooms, despite the fact that 9 of 10 adults claimed to always wash their hands

• Men washed their hands less often than women ( 66% vs. 88%)


Community-Based Mitigation Interventions: Balancing Act

Examples of activities that promote distancing:• School dismissals• Workplace closures• Self-isolation strategies

Unintended consequences:• Economic and personal impact• Disproportionate impact among vulnerable

populations


Basis for Community-Based Strategies

• Evidence from 1918 pandemic• Epidemiologic studies• Modeling• Common sense

Which interventions to use when?

From least restrictive to more restrictive, based on severity of pandemic, since non-pharmaceutical interventions also have unintended consequences.

Cabinet for Health and Family ServicesCollins SD, Frost WH, Gover M, Sydenstricker E: Mortality from influenza and pneumonia in the 50 largest cities of the United States First Edition Washington: U.S. Government Printing Office 1930.

1918 Death Rates: Philadelphia v St. Louis

0

2000

4000

6000

8000

10000

12000

14000

16000

Date

Death

s R

ate

s /

100,0

00 P

op

ula

tio

n

(An

nu

al

Basis

)

Philadelphia

St. Louis

16


Unintended Consequences of Community-Based Strategies

• Economic impact on families and individuals and potential disruption of services due to workplace closures or dismissal of students

• Issues with keeping children and teens from re-congregating in the community

• Disproportionate impact on certain populations


0

5

10

15

20

25

30

35

National SchoolLunch Program

School BreakfastProgram

Summer MealProgram

Par

ticip

ants

(milli

ons)

29.6 million

9.3 million

2.0 million

School Meal Programs FY05

Source: http://www.fns.usda.gov/pd/cnpmain.htm


No One to Care for You If Sick, by Income

% saying they have no one to take care of them at home if they were sick for 7-10 days

24%

36%

25%22%

15%

Total <$25K $25-49.9K $50-74.9K $75K+

Poll results from representative national sample of 1,697 adults conducted in September-October, 2006 by Harvard School of Public Health Project on the Public and Biological Security


Whitley Co. School Dismissal Investigation

• Joint effort between CDC, KDPH, and Whitley Co. HD in March 2008

• What happens to community dynamics when schools close?

• Random telephone survey: 262 surveys completed• Results:

– Most parents agreed with decision to close schools– Most had arrangements for child care for children– More than 40% had children who visited malls, large

department stores or family during the closure– Most understood importance of handwashing as a

prevention strategy, but small percentage mentioned vaccination


School and Child Care Guidance

• When severity is comparable to seasonal flu, schools can remain open in most instances.

• Exclusion period for ill students and staff is at least 24 hours after they have become fever-free (without the use of anti-fever medicines).

• Special environmental cleaning, beyond the routine, is not required.

• http://www.cdc.gov/h1n1flu/schools/schoolguidance.htm


Business Guidance

• Develop/ Refine Continuity of Operations Plans (COOP) to prepare for 40% absenteeism or closure of child care facilities

• Ensure work environment allows for hand washing and social distancing, if possible

• Discuss/disseminate plans and preparations for keeping workers healthy with employees

• Encourage/allow sick workers to stay home


University H1N1 Guidance

• Request residential students who are ill to “self-isolate” until fever-free for 24 hours

• Encourage routine cleaning• Discourage visits to campus from ill persons• Remind health-care students and staff to

follow appropriate infection control policies• Continuity of operations planning (COOP)• http://www.cdc.gov/h1n1flu/institutions/

guidance/


Challenges for Institutions

• Can’t send residential students “home”• Living and working in close quarters• Many international faculty and students with

different backgrounds and cultures


If Severity Worsens…

Consider:• Activating COOP • Liberalizing leave policies• Extending exclusion periods• Suspending events/ dismissing child cares,

schools and workplaces


Closing Thoughts• Current status:

– Transmission mechanisms and severity seem comparable to seasonal influenza

– Higher incidence in children; more complications in pregnant women and in those with chronic diseases

• Situation rapidly evolving– maintain vigilance while waiting to see what clinical course

the virus takes (not alarmed, but concerned)

• Prepare and respond appropriately now– Get a seasonal flu shot, practice good personal behaviors,

remember 3 basic public health strategies– A pandemic affects all sectors of society, so all should

share in the responsibility of addressing the challenge


Good General Resources

• Your local health department• http://www.healthalerts.ky.gov• http://www.cdc.gov• http://www.pandemicflu.gov/: planning

checklists• http://www.ready.gov/


Kentucky Public HealthPrevent. Promote. Protect.

the h1n1 influenza pandemic kentucky optometric association september 8, 2009 kraig e. humbaugh,...

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