Novel H1N1 Influenza UpdateAugust 2009

What did we learn from the Spring 2000 H1N1 experience?

How will the Fall flu season differ from Spring 2009 experience?

Frank J. Welch, MD MSPH

Medical Director, Pandemic Preparedness

Department of Health and Hospitals, Office of Public Health

Louisiana Response: April-May 2009 H1N1 Outbreak

Week 1-3: Aggressive Approach based on initial information from Mexico experience: Emerging Unknown Infection!

Week 4 on: Paradigm Shift! – mild/moderate influenza strain. Focus on serious cases

National Response: Pandemic Declared

• H1N1 virus continues to spread• June 11, 2009: WHO declares a global pandemic

of novel influenza A (H1N1) by raising the worldwide pandemic alert to phase 6

• “Pandemic” is a reflection of the spread of the H1N1 virus, not the severity of illness

H1N1 Transmission Characteristics

• Wide range of symptoms: fever, cough, sore throat, body aches, headache, chills, and fatigue

• Many reports of nausea, vomiting, diarrhea• U.S. has higher than normal Influenza Like Illness • Localized and some intense outbreaks still

occurring• Most people recover without medical intervention• Expected to continue through summer and into fall• Potential, along with seasonal influenza, to cause

significant illness and hospitalizations in the next flu season

International Update

• 2009 H1N1 continues to circulate in tropical countries.• Continuing to increase in southern Africa with more

Africa countries have reported their first cases.• 2009 H1N1 is the predominant influenza virus in

circulation worldwide. • Epidemiology of the disease caused by the 2009 H1N1

influenza virus in the Southern Hemisphere is very similar to that described in the United States this past spring.

• No significant changes detected in the virus isolated in the Southern Hemisphere as compared to viruses isolated in the Northern Hemisphere.

H1N1 in the United States• Most states end case identification in May• Hospitalizations and deaths are still being

counted• U. S. hospitalizations 7983• U. S. deaths 522• Higher levels of influenza activity than is normal

for this time of year• Current visits to doctors for influenza-like illness

are down from April, but higher than what is expected in the summer

•All 50 states with outbreaks occurring•Significantly higher levels of flu-like illness than is normal for this time of year•Anticipate Novel H1N1 to co-circulate with regular seasonal flu and become the dominant strain

H1N1 in the United States

• Hospitalization rates for adults and children for influenza remains low

• Proportion of deaths attributed to pneumonia and influenza is low and within the bounds of what is expected in the summer.

• Activity appears to be increasing in Southeastern U. S.

• Most health officials are reporting local or sporadic influenza activity.

H1N1 in the U. S.

• Any reports of widespread influenza activity in August are very unusual.

• Almost all of the influenza viruses identified were the new 2009 H1N1 influenza A viruses.

• 2009 H1N1 viruses remain similar to the viruses chosen for the 2009 H1N1 vaccine

• Viruses remain susceptible to antiviral drugs (oseltamivir and zanamivir).

Louisiana 2009 H1N1 Outbreak

• 579 lab confirmed cases of novel H1N1 in Louisiana

• Extrapolation of CDC data, real case count is ~33,000

• Increased H1N1 cases reported in recent weeks • Louisiana tests only hospitalized cases• Sentinel surveillance

– Tracks intensity of influenza activity by age and area – Samples sent to CDC for antiviral sensitivity

Fall Planning Assumptions

• Severity of illness will be unchanged from what has already been observed

• Risk groups affected by this virus do not change significantly

• Clinical testing suggests vaccine is a safe and an efficacious product

• Vaccines not yet been licensed, expected to be available in mid-October

• Enough vaccine will be available, but initial does will be prioritized

More Planning Assumptions

• Adequate supplies of vaccine can be produced• No major antigenic changes in the virus

– Efficacy of the vaccines being produced– Antiviral sensitivity

• Model will be very similar to an aggressive seasonal influenza

• Seasonal influenza viruses are still expected to cause illness this Fall

• Individuals encouraged to get their seasonal flu vaccine as it becomes available.

Overall Key Response Differences

Spring: Individual case identification, individual testing, reduce spread, antivirals for every case and contacts

Fall: self isolation of ill individuals, reduce spread, identification and testing of seriously ill persons, antivirals for those most at risk

Key Response Differences

• Clinical Identification and Guidance

– Spring: Individual identification, travel history• Every individual with flu-like symptoms encouraged to

see healthcare provider, get tested, antivirals for patient and all contacts

– Fall: Identification and follow-up of hospitalized• Otherwise healthy individuals encouraged to stay

home and self isolate.• Those with high risk conditions encouraged to seek

medical care and treatment

Key Response Differences

• Laboratory Testing

– Spring: Testing every suspect

– Fall: Testing of all those hospitalized with ILI• Sentinel testing for H1N1 as in seasonal flu

Key Response Differences• Epidemiologic Investigation and follow-up

– Spring: identification and follow-up of every case• Surveillance for individual cases• Case isolation and containment

– Fall: Identification and follow-up of those hospitalized• Surveillance for overall disease prevalence and

trends• Self isolation of ill individuals• Community infection control measures

Key Response Differences• Antiviral Recommendations

– Spring: • Antivirals for all suspected, probable, and

confirmed cases• Antivirals for all contacts of suspected,

probable, or confirmed cases– Fall:

• Antivirals for all high-risk suspected, probable, and confirmed cases

• Antivirals for all suspected and confirmed hospitalized cases

• Post Exposure prophylaxis for exposed healthcare workers

Key Response Differences

• Vaccination– Spring: No vaccine– Fall:

• Encourage seasonal flu vaccination• H1N1 vaccination campaign

Key Response Differences

• Guidance for School Closures– Spring:

• School closure recommendations based on preventing any spread from student to student. Any outbreak or cluster typically closed school for a week

– Fall:• Outbreaks will be handled like seasonal influenza

with the self-isolation at home of ill students and teachers. School closures only when absenteeism is too high.

Key Response Differences

• Media Interest– Spring:

• Media interest intense, speculative• Individual numbers and cases reported

– Fall:• ? Media interest• Media will be a partner in education

Key Response Differences

• Engagement of Response Partners– Spring:

• EOC Operations• Key response partners involved with

response and antiviral deployment– Fall:

• Will depend on outbreak epidemiology

Common Questions

• Is the seasonal flu different than H1N1?• Will we be using the antivirals? What is the

difference between antivirals and vaccine? When is either one used?

• If I get the seasonal flu vaccine does this mitigate the H1N1? Or do I need both?

• Why are there different priority groups for antiviral medications, seasonal influenza vaccine and H1N1 vaccine?

DHH Operational Details

Morning:Battle-Rhythm of Calls (set at M, W, F or adjusted as appropriate)

- to share latest guidance from CDC- to adjust response based on feedback from the field- identification of activities or response plan(s)

Morning – Afternoon:- Intelligence gathering – ie. CDC calls, braintrust calls, etc- Monitoring

Afternoon – Evening:Press Releases (afternoon or early evening in for news broadcasts)

Parish Operations

• Review Continuity of Operations Plans• Cross train staff to support core functions• Review human resource policies for flexibility• Share pan flu planning with employees• Plan for multiple levels of response • Influenza is very difficult to predict• Prepare for multiple scenarios with evolving situation

http://www.cdc.gov/H1N1flu/business/ toolkit/pdf/Business_Toolkit.pdf

Levels of Response

• Similar severity as Spring 2009– Sick persons should stay home– Sick employees at work should be asked to go home– Cover coughs and sneezes– Improve hand hygiene– Cleans surfaces and items that are frequently touched– Encourage employees to get vaccinated– Protect employees at high risk for complications – Prepare for increased employee absences– Plan for essential functions– Prepare for possibility of school dismissal

Additional Level of Responses

• Increased Severity Compared to Spring 2009– Previous actions PLUS– Active screening of employees reporting to work– Alternative work environments for employees at

higher risk for complications– Increasing social distancing in the workplace– Consider canceling non-essential travel– Prepare for school dismissal or closure of child care

programs

Community Actions Prevent the Flu

Cover your nose and mouth with a tissue when you cough or sneeze. Throw the tissue in the trash after you use it.

Wash your hands often with soap and water, especially after you cough or sneeze. Alcohol-based hand cleaners are also effective.

Avoid touching your eyes, nose or mouth. Germs spread this way.

Try to avoid close contact with sick people.

Stay home until you have been symptom-free for 24 hours without fever reducing medicines. This is to keep from infecting others and spreading the virus further.