objectives pandemic influenza then and now public health pandemic influenza planning –what to...
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OBJECTIVES
• Pandemic Influenza Then and Now
• Public Health Pandemic Influenza Planning – What to expect– What not to expect
• Individual/Employee Pandemic Planning
WHAT IS PANDEMIC INFLUENZA?• A global influenza outbreak
– Caused by a change in a flu virus– Most severe occur with big changes in the virus
• Because it is a drastically changed virus, few or no people would be immune
• Many people would get sick in every part of the world
• Asia is the source of many outbreaks because swine, birds and humans live under the same roof, providing opportunity for viral mixing
HOW DOES INFLUENZA VIRUS CHANGE?• Antigenic Drift:
– Small changes in virus over time– New strains appear and replace older strains– May not be recognized by antibodies to older strains
• Antigenic Shift: – Abrupt, major change (reassortment)– Results in novel strain or new subtype– Can cause pandemic influenza
PANDEMIC INFLUENZA CYCLE• Recognized global outbreaks of influenza since the
1500’s• Historical cycles of 10 to 40 years• Rapid transmission worldwide.• High attack rate for all age groups.• High mortality rates, esp. for young adults.
1918: Spanish Flu A(H1N1)
20-40 m deaths675,000 US deaths
1957:AsianFlu A(H2N2)
1-4 m deaths70,000 US deaths
1968: Hong Kong Flu A(H3N2)
1-4 m deaths34,000 US deaths
Influenza Pandemics 20th Century
GLOBAL STATUS OF CURRENT PANDEMIC THREAT
• World Health Organization (WHO) defines 3 major periods (broken into 6 phases) of increasing human infection with new flu virus:
– Interpandemic (no human infection)
– Pandemic Alert (limited human infection)
– Pandemic (widespread human infection)
• We are at Pandemic Alert
• Isolated human infections with a novel influenza strain [H5N1] with no (or rare) person-to-person transmission.
Country
2003 2004 2005 2006 2007 2008 Total
casesdeath
scases
deaths
casesdeath
scases
deaths
casesdeath
scases
deaths
casesdeath
s
Azerbaijan 0 0 0 0 0 0 8 5 0 0 0 0 8 5
Cambodia 0 0 0 0 4 4 2 2 1 1 0 0 7 7
China 1 1 0 0 8 5 13 8 5 3 0 0 27 17
Djibouti 0 0 0 0 0 0 1 0 0 0 0 0 1 0
Egypt 0 0 0 0 0 0 18 10 25 9 0 0 43 19
Indonesia 0 0 0 0 20 13 55 45 42 37 9 8 126 103
Iraq 0 0 0 0 0 0 3 2 0 0 0 0 3 2
Lao People's Democratic Republic
0 0 0 0 0 0 0 0 2 2 0 0 2 2
Myanmar 0 0 0 0 0 0 0 0 1 0 0 0 1 0
Nigeria 0 0 0 0 0 0 0 0 1 1 0 0 1 1
Pakistan 0 0 0 0 0 0 0 0 1 1 0 0 1 1
Thailand 0 0 17 12 5 2 3 3 0 0 0 0 25 17
Turkey 0 0 0 0 0 0 12 4 0 0 0 0 12 4
Viet Nam 3 3 29 20 61 19 0 0 8 5 1 1 102 48
Total 4 4 46 32 98 43 115 79 86 59 10 9 359 226
Source World Health Organization
WILL H5N1 BE THE NEXT PANDEMIC?• Impossible to know if or when
• If not H5N1, then another will come
• The prudent time to plan is now
AVIAN FLU• OCCURS
REGULARLY IN AVIAN SPECIES
• SOMETIMES SPREADS TO OTHER SPECIES
PANDEMIC FLU• OCCURS
PERIODICALLY IN HUMANS
• CAN BE CAUSED BY ANY STRAIN OF INFLUENZA VIRUS
PLANNING ASSUMPTIONS: DISEASE TRANSMISSION
• No one immune to virus; 30% of population will become ill
• People may be contagious up to 24 hours before they know they are sick
• People are most contagious the first 2 days of illness
– Sick children are more contagious than adults
• On average, each ill person can infect 2 or 3 others (if no precautions are taken)
Medical Burden in Knox CountyBased on 2006 Knox County population estimate of 399,254
Characteristic Moderate* Severe*
Illness 119,775 [30% of pop] 119,775 [30% of pop]
Outpatient care 59,890 [50% of ill] 59,890 [50% of ill]
Hospitalization 1,200 [1% of ill] 13,175 [11% of ill]
ICU Care 180 [15% of hosp] 1,975 [15% of hosp]
Mechanical Ventilation 90 [50% of ICU] 990 [50% of ICU] Deaths (Case fatality rate) 240 [0.2% of ill] 2,395 [2% of ill]
HEALTH AND HUMAN SERVICES PLANNING OBJECTIVES
• Primary objective:
– Minimize sickness and death
• Secondary objectives:
– Preserve functional society
– Minimize economic disruption
INFLUENZA CONTAINMENT STRATEGIES• Routine Activities
– Surveillance• 911 calls• ER visits• Sentinel physicians
– Public information and education– Promote “respiratory hygiene” and hand washing
• Unique Activities– Measures to increase social distancing– Change how we perform our day-to-day business to protect
our staff and patients who still need our services
INFLUENZA CONTAINMENT• Very early isolation and quarantine• Reduce social contact
– Stay home if you are sick– Canceling large gatherings, mass transit, schools
• Decision based on location of flu activity:– Outbreak not local: gatherings >10,000 cancelled– Outbreak in local/neighboring county: >100
• School closings determined by State Commissioner of Health/Board of Education.
• Heavy reliance on personal measures
INFLUENZA CONTAIMENT, PERSONAL MEASURES• Hand Hygiene
– Frequent washing– 60%-95% alcohol-based
sanitizer• Respiratory Hygiene
– Cover your cough • Environmental cleaning
– 1:10 bleach solution– EPA registered disinfectant
• Gloves & surgical masks for direct contact with ill person• These apply at home and at work
Flu Vaccine • Production minimum 6
month process:(growing 93 million eggs)
• HHS priority groups– Military and vaccine
manufacturers– Healthcare workers with
direct patient care– Persons at highest risk
for complications• Two doses needed for
protection
Tamiflu• Anti-viral agent• Could be used to contain
first human outbreak• Resistance described• Should be used within 48 of
infection• HHS priority groups: military
and hospitalized patients• Tamiflu ≠ Preparedness
Guidance for Families
• Plan for childcare in the event schools close
• Arrangements made for eldercare, pet care
• Discuss/develop plan with employer how you might work at home
Guidance for Families• Personal protection:
– Hand hygiene and respiratory etiquette– Surgical masks: proven effective for
droplet precautions – Pneumococcal vaccination of those for whom it is
recommended
• Stockpiling: One to three week essential water, food, supplies, medicines
RESOURCES
• PandemicFlu.gov
• CDC.gov/flu/avian
• www.nyhealth.gov
• Knoxcounty.org/health