2009 Novel H1N1 Influenza:A Situational Update with a

focus on Asthma

November 10, 2009Michigan Department of

Community Health

The “Virus” is here

When we are talking about the flu

The Influenza Virus

Influenza Overview Orthomyxoviridae, enveloped RNA virus Strains

– Type A– Type B– Type C

Further classified by surface protein– Neuraminidase (N) – 9 subtypes known– Hemagglutinin (H) – 16 subtypes known

Transmission is respiratory by spread of droplets/secretions

Source: CDC

Influenza

This new virus transmits efficiently from one human to another

2009 Novel Influenza A H1N1

It is a new influenza virus thus the general population has little/no immunity

This new virus replicates in humans and cause disease

Influenza Pandemic

Circulating Influenza Strains and Pandemics in The 20th Century

1920 1940 1960 1980 2000

H1N1H2N2

H3N2

1918: “Spanish Flu” 1957: “Asian Flu” 1968: “Hong Kong Flu”

20-40 million deaths 1-4 million deaths 1-4 million deaths

Novel H1N1 Confirmed and Probable Case Rate in the United States, By Age GroupSpring 2009

Novel H1N1 U.S. Deaths, By Age GroupSpring 2009

H1N1 Response PillarsFederal, State and Local Levels Surveillance Mitigation

– Prevention– Early Detection– Isolation– Treatment

Vaccination Communication

SurveillanceSeasonal Influenza Impacts

US Average 36,000 deaths/year Average 226,000 hospitalizations/year

MI (based on 3.3% US population) 1,188 deaths/year 6,600 hospitalizations/year

Surveillance

MI Emergency Room VisitsUS Sentinel Physician Visits

WinterSpring

Fall

CURRENT

LAST YEAR

Percentage of Visits for Influenza Like Illnes (ILI) Reported by the US Outpatient Influenza-like Illness Surveillance Network (ILINet) - Michigan, 2007-2010

0.0%

1.0%

2.0%

3.0%

4.0%

5.0%

6.0%

7.0%

8.0%

9.0%

10/4

10/18

11/1

11/15

11/29

12/13

12/27

1/10

1/24

2/72/2

13/7

3/21

4/44/1

85/2

5/16

5/30

6/13

6/27

7/11

7/25

8/88/2

29/5

9/19

Week Ending Dates

Perc

ent

ILI

2007-08

2008-09

2009-10

Baseline

Available at: www.michigan.gov/flu, click on ‘Michigan’ under Current Influenza Activity

Community Mitigation

Individual and family actions School/community responses Hospital preparedness/surge response Infection Control Treatment

School Dismissals

Antivirals New guidance (September 8, rev Oct 19) Treatment for patients with influenza and at

high risk – People without severe illness and/or are

not at high risk should not receive antiviral medication

– Clinical judgment is important factor – Lab testing generally reserved for

hospitalized patients – Chemoprophylaxis is discouraged

Antiviral Resistance

To date, 14 resistant nH1N1influenza viruses detected in US All of these viruses show the same

H275Y mutation– confers resistance to the antiviral oseltamivir– but not to the antiviral zanamivir

Vaccination Target groups for seasonal and nH1N1

vaccines differ Four companies licensed by FDA for

nH1N1 Initial delay in nH1N1 vaccine

production– Improving daily/weekly– Initial target groups vital

Influenza Target Group ComparisonSeasonal Flu Target Groups 2009 H1N1 Initial Target GroupsPregnant women Pregnant women

Children aged 6 mo-18 yrs Persons aged 6 mo-24 yrs

Persons aged 19-49 yrs with a medical condition* that puts them at higher risk

Persons aged 25-64 yrs with a medical condition* that puts them at higher risk ±

Adults aged 50 yrs and older ± see belowHealth care personnel Health care personnel and emergency

medical services personnel

Persons living with or caring for children birth-4 yrs, adults over 49 yrs & those with a medical risk condition

Persons living with or caring for infants less than 6 mo of age

Residents of long-term care facilities ± see below± Expanding vaccination beyond initial target groups: When it is determined by state and local health departments that vaccine is in greater supply, vaccinate 1) healthy persons 25-64 yrs of age and then2) persons 65 years of age and older* See next slide for list of medical conditions

8

What are the Medical Risk Conditions?

Medical risk conditions are similar for both seasonal and 2009 H1N1 and include:– Children 6 mo-18 years on long-terms asprin therapy– Persons with the following conditions or disorders:– chronic pulmonary (including asthma)– Cardiovascular (except hypertension)– Renal or hepatic – Neurologic or neuromuscular – Hematologic or metabolic (including diabetes)– Immunosuppression (including that caused by medications or

HIV)

9

H1N1 and Asthma

OUTREACH TO PERSONS WITH ASTHMA ABOUT 2009

H1N1 RISKS AND PREVENTION(FROM CDC – Air Pollution & Respiratory Health Branch)

Persons With Asthma

Increased risk of severe complications and death in previous influenza pandemics

Influenza immunization rates among have been historically suboptimal (36% in recent studies)

Relative to the general population, are at increased risk of morbidity and mortality related to seasonal influenza infection

Persons With Asthma

Relative to the general population, are at increased risk of morbidity and mortality related to 2009 H1N1 influenza (“swine flu”) infection.

Nearly 6.7 million asthma sufferers are under age 18

Asthma disproportionately impacts minority members and other socio-economically disadvantaged groups.

Overarching Messages

Key messages for persons with asthma and health-care providers

Persons with asthma

1. Take everyday preventive actions– Follow an updated, written Asthma Action Plan

developed with your doctor. – Cover your nose and mouth with a tissue when

you cough or sneeze, or sneeze into your sleeve– Wash hands– Avoid touching nose, mouth and eyes– Stay at home if you’re sick – except to get

medical care

Persons with asthma

2. Take time to get vaccinated– Persons with asthma should get the 2009 H1N1

flu vaccine as well as a seasonal influenza vaccine

– Persons with asthma should not use the inhaled "FluMist®" vaccine because of the increased risk of wheezing post-vaccination.

Persons with asthma

3. Take flu antiviral drugs if your doctor recommends them– Fight against the flu by keeping the germs from growing in

your body. – Can make you feel better faster and make symptoms milder – Relenza® (zanamivir) is not recommended for treatment in

persons with asthma – Work best when started soon after symptoms begin (within 2

days) - they may also be given to very sick or high-risk people (like persons with asthma) even after 48 hours.

Health Care Providers

1. Preventive actions– Persons with asthma should have and use an

updated, written Asthma Action Plan– Asthma Action Plan should include steps to be

taken at the earliest onset of symptoms of influenza-like illness

– Asthma Action Plan on file at their school or daycare center, and the plan and medication(s) should be readily accessible

Health Care Providers

2. Vaccinations– 2009 H1N1 flu vaccine and the seasonal

influenza vaccine– Persons with asthma should not use the inhaled

FluMist® vaccine because of the increased risk of wheezing post-vaccination.

– A person with asthma who gets any type of flu is at risk for serious complications and hospitalization.

Health Care Providers

3. Antivirals– Treat quickly - should not be withheld pending

results of testing for influenza– Persons with asthma with influenza-like illnesses

should receive empiric antiviral treatment – Zanamivir (trade name, Relenza®) is not

recommended for treatment in patients with asthma

– Post-exposure antiviral chemoprophylaxis can be considered for persons with asthma who have had contact with someone likely to have been infectious with influenza.

Health Care ProvidersAntivirals, cont.

Providers should develop methods to ensure that treatment can be started quickly after symptom onset – Informing patients or their caretakers of signs and symptoms

of influenza and the need for early treatment after symptom onset.

– Rapid access to telephone consultation and clinical evaluation for persons with asthma and other high risk conditions

– Considering empiric treatment of persons with asthma based on telephone contact if hospitalization is not indicated and if this will substantially reduce delay before treatment is initiated

2009 H1N1 and People with Asthma Resources

http://www.cdc.gov/H1N1flu/asthma/

Pneumococcal Polysaccharide Vaccine (PPSV23) and Influenza

Influenza predisposes persons to bacterial community-acquired pneumonia

Ensure high risk patients have received PPSV23 vaccine – Any person age 65 years or older– Any person 2-64 years with a high-risk condition

New recommended groups for vaccination are:– Persons 19 years of age or older who have asthma or who

smoke cigarettes

No more than 2 lifetime doses are recommended, spaced at least 5 years apart

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Communications

Primary federal websites – www.flu.gov

– http://www.cdc.gov/h1n1flu/

Primary state website– michigan.gov/flu

…prepare for the worst

Hope for the best and…

QUESTIONS?