Download H1N1 Global Pandemic 2009 Kevin Sherin, MD, MPH, FACPM, FAAFP Director

H1N1 Global Pandemic 2009
Kevin Sherin, MD, MPH, FACPM, FAAFP
Director
Orange County Health Department
What is H1N1 Swine Flu?

It’s not like other recent human H1N1’s. Pieces come from birds, pigs, and people.
Pandemic H1N1/09 Virus

First Cases:
-Mexico early March, California
early April
 Spread:
-This virus has spread 4 x as fast
as 1918 pandemic influenza
 Severity:
-WHO classified as Moderate
- 1/3 of lethal cases may have
had no determined underlying
disease
-1918 had 1-2% mortality
 Strain:
-8 strands, 5 porcine, 1 human, 2
avian
-Recombination, 12 Countries
including the U.S.
Flow of H1N1 Info
Containment to Mitigation

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The virus is widespread in the community
Individual case investigation, contact quarantine & contact tracing is no longer feasible
or effective

Voluntary measures to reduce person-to-person spread

Self-isolation of the sick

Encourage good respiratory hygiene, handwashing

Sensible, practical methods to reduce transmission in public and private settings

Help treatment facilities provide appropriate care

Reduce healthcare amplify of infection

Make best use of available treatment drugs and equipment to reduce morbidity and
mortality

Coordinate public health and healthcare responses

Health Department Measures

Investigation of critical cases and deaths

Outbreak investigations

Influenza Surveillance

Provide public and medical community with accurate information and guidelines
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What Can We Hope to Accomplish?

Reduce total number of cases

Reduce number of deaths
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Spread out cases over a longer period

Delay cases until vaccine is available

Protect the Public’s Health!
6
H1N1 Statistics (Sept. 4)
U.S.
 593 Deaths
World
 2,837 Deaths (WHO)

9,079
Hospitalizations

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68,222 Confirmed
Cases in 50 states
and 4 territories
(unofficial count)
254,206 Cases
(WHO)
The WHO and the CDC are no longer counting individual cases. CDC will report hospitalizations and deaths
weekly and as well as data from traditional influenza surveillance systems. Unofficial counts are based on
media reports\.
International Co-circulation of 2009 H1N1 and Seasonal Influenza
As of September 2
U.S. Influenza Activity
Note the widespread activity in Southeastern states
Current Surveillance by FL DOH
State public health laboratory
 100 sentinel providers
 ESSENCE syndromic surveillance system
(Hospital ED’s)
 County health departments
 Weekly count of deaths
 Outbreak investigations
 Local systems (e.g. school absenteeism)

Florida Statistics- September 2
Florida
 644 hospitalizations
 70 deaths
 51 cases in pregnant
women
 Numerous outbreaks
in daycares, camps,
correctional facilities,
workplaces, and
schools.
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County Influenza Activity based on
Surveillance Reports
Based on number of outbreaks reported, ILI activity detected through
local surveillance systems and lab evidence of influenza in the community.
ESSENCE: ED visits for ILI
The percent of emergency department visits associated with influenza-like illness is greatest in the
<1-19 age group, and now exceeds the percent observed during the initial increase in May 2009.
Increases since June are mostly occurring in the younger and middle age groups.
Laboratory Surveillance
FIGURE 4. The Bureau of Laboratories is now reporting that 50% of the specimens
submitted to them are positive for influenza. Of those positive for influenza, 98%
were novel H1N1 influenza. The remaining 2% were seasonal influenza B.
Clinical Presentation
Transmission

Seasonal human influenza viruses- are thought to spread from person to person
primarily through large-particle respiratory droplet transmission (e.g., when an
infected person coughs or sneezes near a susceptible person).

Transmission via large-particle droplets requires close contact between source
and recipient persons because droplets do not remain suspended in the air and
generally travel only a short distance (< 6 feet).

Contact with contaminated surfaces is another possible source of transmission
and transmission via droplet nuclei (also called “airborne” transmission).

Because data on the transmission of novel H1N1 viruses are limited, the potential
for ocular, conjunctival, or gastrointestinal infection is unknown. Since this is a
novel influenza A virus in humans, transmission from infected persons to close
contacts may be common.

All respiratory secretions and bodily fluids (diarrheal stool/vomitus) of novel
influenza A (H1N1) cases should be considered potentially infectious.
Novel H1N1 vs. Seasonal H1N1
In vitro and in vivo characterization of new swine-origin H1N1
influenza viruses. Nature, Yasushi et al,13 July 2009
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Novel H1N1 was found to replicate more efficiently in mice,
ferret, and non-human primate models than seasonal H1N1.
Novel H1N1 was found to cause more severe pathological
lesions in mice vs. seasonal H1N1.
Novel H1N1 was found to have a similar transmission pattern
to seasonal H1N1 viruses.
High transmissibility that we are currently seeing likely due to
lack of pre-existing immunity among majority of the population.
We are not seeing increased severity but are seeing severe
illness in atypical age group for influenza.
Incubation Period
Incubation period
 The estimated incubation period is
unknown and could range from 1-7 days,
but more likely 1-4 days.

Infectious period

The duration of shedding of H1N1 virus is unknown. Estimated is
based on data for seasonal influenza infection.

Seasonal Flu Shedding: one day before onset until resolution of
symptoms; typically 1 day before to 7 days after illness onset.
Children, especially younger children, might be infectious for up to
10 days.

New Self-Isolation Guidelines from CDC : Self-isolation (no school
or work) should be recommended for all patients presenting with ILI
until 24 hours after fever resolves (<100° F) without the use of a
fever reducer.

Isolation guidelines remain the same for healthcare workers: 7 days
from onset or until symptoms resolve, whichever is longer.
Seasonal Flu High Risk Groups

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Children less than 5 years old and adults aged 65 yrs or
older
Children and adolescents (< 18 years) receiving longterm aspirin therapy (Reye’s syndrome)
Pregnant women
Adults and children who have chronic pulmonary,
cardiovascular, hepatic, hematological, neurologic,
neuromuscular, or metabolic disorders
Persons who have immunosuppression (including
immunosuppression caused by medications or by HIV)
Residents of nursing homes and other chronic-care
facilities
Children
CDC MMWR on Pediatric Deaths Associated w/ H1N1-Sept.4

67% of H1N1 deaths in kids less than 18yrs had underlying medical
conditions,
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92% of which were neurodevelopmental (developmental delay or cerebral
palsy).
41% had both neurodevelopmental and chronic pulmonary conditions.
In children w/ cultures done, 43% had bacterial co-infection; co-infection
was found in all cases less than 5 yrs old.
Almost 50% of H1N1 cases in FL are in children 18 and under, who are
less than 25% of the population.
 Most H1N1 outbreaks were associated with daycares or camps this
summer in FL.
 13% of H1N1 deaths are in persons <24 yrs in FL.
 They include: 1 death in a child less than 4 yrs, 9 deaths in persons 5-24
yrs, 6 with underlying medical conditions.
Pregnancy

H1N1 2009 influenza virus infection during pregnancy in the USA, The
Lancet, Jamieson et al, 29 July 2009

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From April 15 to July 16, 13% of H1N1 associated deaths are in pregnant women
Pregnant women are at increased risk for H1N1 complications
Pregnant women have a higher rate of hospitalization than the general public

Per CDC data, pregnant women are 4 times as likely to be hospitalized for
H1N1 than the general population.

Pregnant women with influenza-like illness should be treated promptly with
antiviral medications.

Pregnancy should not be considered a contraindication to oseltamivir or
zanamivir use. The benefits outweigh the risks.

Oseltamivir is preferred to zanamivir in pregnant women.
Antiviral Medications
Oseltamivir (Tamiflu)
 Prophylaxis: once a day
for 10 days
 Treatment: twice a day
for 5 days
 Dosage: based on
weight/age
 EUA for prophy in
children less than 1 yr
old



Zanamivir (Relenza)
Prophylaxis: two 5mg
inhalations once a day
for 10 days
Treatment: two 5mg
inhalations twice a day
for 5 days
Only treat those who are high risk!
Complications
Clinicians should expect complications to be similar to seasonal influenza:
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exacerbation of underlying chronic medical conditions
upper respiratory tract disease (sinusitis, otitis media, croup)
lower respiratory tract disease (pneumonia, bronchiolitis, status
asthmaticus)
cardiac (myocarditis, pericarditis)
musculoskeletal (myositis, rhabdomyolysis)
neurologic (acute and post-infectious encephalopathy, encephalitis,
febrile seizures, status epilepticus)
toxic shock syndrome
and secondary bacterial pneumonia with or without sepsis
Critically ill 25 year old H1N1 patient
http://www.cfnews13.com/Health/YourHealth/2009/9/1/man39s_3month_bat
tle_with_swine_flu_ends_wednesday.html
How Does Influenza Kill?

Primary pneumonia – viral
Secondary pneumonia – bacterial
 Both congest airways and make
breathing impossible
 Contribute to deaths from heart
attack, stroke, cancer, etc.
Deaths associated with novel
H1N1
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75% have underlying chronic disease
Age distribution is different from that for all confirmed cases
In many cases there was late initiation of antiviral treatment due
to delayed medical evaluation or misdiagnosis as bacteria illness
Important for high risk individuals to seek medical attention early
in illness to avoid complications
Emergency Symptoms :
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has difficulty breathing or chest pain
has purple or blue discoloration of the lips
is vomiting and unable to keep liquids down
has signs of dehydration such as dizziness when standing, absence
of urination, or in infants, a lack of tears when they cry
has seizures (for example, uncontrolled convulsions)
is less responsive than normal or becomes confused
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Cases and Deaths by Age Group
Number of Deaths
Deaths are occurring in older age groups than cases
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0-4
5-24
25-49
50-64
65+
Age Group
New ly reported
Year-to-date
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Influenza Rapid Test
H1N1 Confirmatory Testing

Since July 13, the DOH Bureau of Laboratories has only test for the novel
2009 H1N1 virus specimens from:
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Patients with life-threatening illnesses,
Patients from county health departments investigating suspected influenza
outbreaks
Patients from the Florida network of sentinel surveillance practices.
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RT-PCR testing to detect the novel H1N1 virus is now also available through
at least one commercial laboratory (Quest), and some local hospital
systems.
Specimen- nasopharyngeal swab or aspirate, nasal swab plus a throat swab
or nasal wash, or tracheal aspirate should be collected. (Nasopharyngeal
swabs are preferred)
Wear appropriate PPE when collecting the specimen
Not all people with suspected novel influenza (H1N1) infection need to have the
diagnosis confirmed, especially if the illness is mild.
Remember 99% of current circulating flu is H1N1!
Infection Control
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Patients with ILI who present for care at a healthcare
facilities should be placed directly into individual rooms
and the door should be kept closed
The ill person should wear a surgical mask to contain
secretions when outside of the patient room
Healthcare personnel entering the room of a patient in
isolation should be limited to those performing direct
patient care.
Infection Control

All healthcare personnel who enter the rooms of suspect H1N1
patients should wear a fit-tested disposable N95 respirator or
better (CDC/IOM). FL DOH recommends the use of surgical
masks for routine contact.

In a Healthcare setting- Isolation precautions for 7 days from
symptom onset or until symptoms resolve, whichever longer.

Asymptomatic healthcare personnel who have unprotected
exposure to novel H1N1 may continue to work if they are started
on antiviral prophylaxis.
Intervention Strategy:
H1N1 Swine Flu Vaccine
•
Initial doses will be made
available when received from
CDC- tentatively mid-October
•
The H1N1 shot will be separate
from the seasonal flu shot- it is
unknown whether the H1N1 and
seasonal shots can be
administered at the same time
•
Shots will be VOLUNTARY and
FREE
•
Will likely involve 2 doses
separated by 21 to 28 days.
Drive-Thru Vaccine POD
Vaccine – Initial Target Groups
•
•
•
•
•
Pregnant women
Health care workers and emergency services personnel
People caring for infants under 6 months of age
Children and young adults from 6 months to 24 years
People aged 25 to 64 years with underlying medical
conditions (e.g. asthma, diabetes, respiratory or cardiac
illness)
Resource: http://www.pandemicflu.gov/vaccine
** Older people may have protection against H1N1 **
Subset of Target Groups During
Limited Vaccine Availability
Same groups as previous slide with
following 2 caveats
 children aged 6 months--4 years
 children and adolescents aged 5--18
years who have medical conditions that
put them at higher risk for influenzarelated complications

Prevention Messages

Wash your hands

Cough or sneeze into your sleeve or elbow,
when a tissue is not available.

Try to stay in good general health by getting
plenty of sleep, drink plenty of fluids, and eat
nutritious food.

STAY HOME IF SICK- at least 24 hours after fever
is gone for the general public; 7 days after
symptoms begin or until all symptoms are gone,
whichever is longer, for all health care workers

Get vaccinated as soon as vaccines become
available (for seasonal flu) and if you are in the
target group (for H1N1 swine flu).
For more flu information, visit: www.myflusafety.com
Public Education Efforts
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Press releases
Numerous media interviews
Articles in Medical Society newsletter
Blast emails to local providers
Contact with public and private schools,
universities, major employers, daycares,
hospitals, clinics, etc.
 Education material provided to schools,
daycares created by Orange CHD.
Protect! Don’t Infect!
(PDI) www.protectdontinfect.com
Questions?

[email protected]