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Transcript of WHO PANDEMIC PHASES INTERPANDEMIC PERIOD Phase 1 Phase 2 PANDEMIC ALERT PERIOD Phase 3 Phase 4 Phase...
WHO PANDEMIC WHO PANDEMIC PHASESPHASES
INTERPANDEMIC PERIOD
Phase 1
Phase 2
PANDEMIC ALERT PERIOD
Phase 3
Phase 4
Phase 5
PANDEMIC PERIOD
Phase 6
POSTPANDEMIC PERIOD
INFLUENZA VIRUS
MILESTONES IN INFLUENZAMILESTONES IN INFLUENZA
1933 Demonstration of virus transmission to ferrets Smith et al. 1933
1937 Growth of influenza virus in hens’ eggs Francis & Magill 1937
1941 Agglutination of erythrocytes by influenza Hirst 1941
1943 Extensive clinical trials in USA showed vaccine was 70% effective Francis 1943
1945 Vaccination of US Army showed consistent protection Francis et al. 1946
1945 Licence of first influenza vaccine in USA
I cannot forecast to you the action of Russia. It is a riddle wrapped in a mystery inside an enigma.
Sir Winston ChurchillRadio Broadcast, October 1, 1939
I cannot forecast to you the pandemic impact of this influenza virus. Influenza virus is a riddle wrapped in a haemagglutinin – neuraminidase encrusted envelope inside an enigma
Barry D SchoubNICD, June 22, 2009
A.A. SPORADIC INFLUENZASPORADIC INFLUENZA
B.B. PANDEMIC INFLUENZAPANDEMIC INFLUENZA
C.C. SEASONAL INFLUENZASEASONAL INFLUENZA
NICD
A.A. SPORADIC INFLUENZASPORADIC INFLUENZA
B.B. PANDEMIC INFLUENZAPANDEMIC INFLUENZA
C.C. SEASONAL INFLUENZASEASONAL INFLUENZA
HUMAN CASES OF AVIAN INFLUENZA
Year Subtype No. of Cases Location
1997 H5N1 18 (6 deaths) Hong Kong
1999 H9N2 2 (children ages 4 yr, 13 mo) Hong Kong
2002 H7N2 1 United States (Virginia)
2003 H5N1 2 (1 death) Hong Kong
2003 H7N7 89 (1 death) The Netherlands
2003 H7N2 1 New York
2003 H9N2 1 (child) Hong Kong
2003- (ongoing)
H5N1 262/440 (60%) Vietnam, Thailand, Cambodia, Indonesia, China, Turkey, Iraq, Azerbaijan, Egypt etc
2004 H7N3 2 Canada (British Columbia)
2004 H10N7 2 (infants) Egypt
NICD
A.A. SPORADIC INFLUENZASPORADIC INFLUENZA
B.B. PANDEMIC INFLUENZAPANDEMIC INFLUENZA
C.C. SEASONAL INFLUENZASEASONAL INFLUENZA
INFLUENZA PANDEMICSINFLUENZA PANDEMICS
15101510 1889 – 18901889 – 1890 H2N2H2N2 1899 – 19001899 – 1900 H3N2H3N2 1918 – 19191918 – 1919 H1N1H1N1 “Spanish flu” “Spanish flu” 1957 – 19581957 – 1958 H2N2H2N2 “Asian flu” “Asian flu” 1968 – 19691968 – 1969 H3N2H3N2 “Hong Kong flu” “Hong Kong flu”
NICD
A.A. SPORADIC INFLUENZASPORADIC INFLUENZA
B.B. PANDEMIC INFLUENZAPANDEMIC INFLUENZA
C.C. SEASONAL INFLUENZASEASONAL INFLUENZA
INFLUENZA PANDEMICS
15101510 1889 – 18901889 – 1890 H2N2H2N2 1899 – 19001899 – 1900 H3N2H3N2 1918 – 19191918 – 1919 H1N1H1N1 “Spanish flu” “Spanish flu” 1957 – 19581957 – 1958 H2N2H2N2 “Asian flu” “Asian flu” 1968 – 19691968 – 1969 H3N2H3N2 “Hong Kong flu” “Hong Kong flu”
NICD
1977 H1N1
RECOMMENDED VACCINE RECOMMENDED VACCINE FORMULATIONFORMULATION
The following strains have been recommended by the WHO for the 2009 Southern Hemisphere influenza season:-
A/Brisbane/59/2007 (H1N1) - like virus *
A/Brisbane/10/2007 (H3N2) - like virus **
B/Florida/4/2006 - like virus #
* A/South Dakota/6/2007 (an A/Brisbane/59/2007-like virus) is a current vaccine virus used in live attenuated vaccines** A/Brisbane/10/2007 and A/Uruguay/716/2007 (an A/Brisbane/10/2007-like virus) are current vaccine viruses# B/Florida/4/2006 and B/Brisbane/3/2007 (a B/Florida/4/2006-like virus) are current vaccine viruses
ONSET & DURATION OF INFLUENZA ONSET & DURATION OF INFLUENZA SEASON: 1985 - 2007SEASON: 1985 - 2007
Median onset:Median onset: Week 23Week 23 Range 15-28Range 15-28
Median peak:Median peak: Week 27Week 27 Range 20-32Range 20-32
Median Median duration:duration: 10 weeks10 weeks Range 7-17Range 7-17
Epidemiological week
15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
19851986
198719881989
19901991
19921993
1994
19951996
19971998
1999
20002001
200220032004
2005
2006
Mean onset
2007
Apr May Jun Jul Aug Sep
INFLUENZA VIRUS
(9 subtypes)
(16 subtypes)
NICD
HAEMAGGLUTININSHAEMAGGLUTININS H1H1 N1N1 NEURAMINIDASESNEURAMINIDASES
H2H2 N2N2
H3H3 N3N3
H4H4 N4N4
H5H5 N5N5
H6H6 N6N6
H7H7 N7N7
H8H8 N8N8
H9H9 N9N9
H10H10
H11H11
H12H12
H13H13
H14H14
H15H15
H16H16
PANDEMICS
1918 H1N1 SPANISH PANDEMIC
1957 H2N2 ASIAN PANDEMIC
1968 H3N2 HONG KONG PANDEMIC
H5N1 AVIAN INFLUENZA NICD
INFLUENZA PANDEMICS
15101510 1889 – 18901889 – 1890 H2N2H2N2 1899 – 19001899 – 1900 H3N2H3N2 1918 – 19191918 – 1919 H1N1H1N1 “Spanish flu” “Spanish flu” 1957 – 19581957 – 1958 H2N2H2N2 “Asian flu” “Asian flu” 1968 – 19691968 – 1969 H3N2H3N2 “Hong Kong flu” “Hong Kong flu” 2009 - ? H1N1 v “Swine flu”/pandemic 20092009 - ? H1N1 v “Swine flu”/pandemic 2009
NICD
H1N1
1918/19 Pandemic1918
Ag Stasis
(sporadic human cases)
Triple reassortant
Influenza A (H1N1) v
2009 Pandemic
Eurasian
Ag drift
Seasonal flu
Ag drift
Seasonal flu
1957
1977
1998
2009
Positive samples by influenza types and subtypes : Viral Watch South Africa 2009
0
50
100
150
200
250
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51
Week
Nu
mb
er
0
20
40
60
80
Pe
rcen
tag
e
A awaiting typing A H1N1 (seasonal) A H3N2
B Novel H1N1 Detection rate**
Diagnosed and reported H1N1 influenza statistics
Infected individuals
Symptomatically infected
Report to doctor
Doctor takes specimen
Diagnosed and reported H1N1 influenza statistics
Adequate specimen reaches laboratory
Laboratory test reliable
Reported to surveillance authority
PANDEMIC H1N1 DEATHSPANDEMIC H1N1 DEATHS (31(31STST August 2009) August 2009)
TOTAL = 27TOTAL = 27
A) A) PREGNANCYPREGNANCY:: 12 (44%)12 (44%)StageStage:: 11stst trimester trimester 11
33rdrd trimester trimester 1010PuerperiumPuerperium 11
Co-morbidityCo-morbidityNoneNone 5 (42%)5 (42%)Under investigationUnder investigation 11HIVHIV 44TB (only)TB (only) 11Obese + substance abuseObese + substance abuse 11
Age distributionAge distributionRangeRange 16-3716-37
B)B) NON-PREGNANTNON-PREGNANT
Total:Total: 1515
Age range:Age range: 0-53yr0-53yr
a)a) NilNil 33 (20%)(20%)
b)b) Co-morbiditiesCo-morbidities
1.1. HIVHIV 22 (1 TB)(1 TB)
2.2. ObesityObesity 77 (1 asthma, 2 cardiac, 1 (1 asthma, 2 cardiac, 1 diabetes)diabetes)
3.3. DiabetesDiabetes 44 (1 obesity, 1 hypertension)(1 obesity, 1 hypertension)
4.4. TBTB 11
5.5. Premature Premature 11
WHO PANDEMIC WHO PANDEMIC PHASESPHASES
INTERPANDEMIC PERIOD
Phase 1
Phase 2
PANDEMIC ALERT PERIOD
Phase 3
Phase 4
Phase 5
PANDEMIC PERIOD
Phase 6
POSTPANDEMIC PERIOD
CHARACTERISTICS OF PANDEMICS
1. Novel virus
2. Increased transmissibility
3. +/- increased virulence
4. Age shift
5. Relative non-seasonality
6. Geographic heterogeneity
7. Multiple waves
8. Human adaptation seasonal influenza
NICD
3. VIRULENCE
CFR: MEXICO 0.4% (0.3 – 0.6%)
USA 0.2%
SEASONAL 0.04-0.08%
INFLUENZA
1918/1919 5.0%
PANDEMIC
H5N1 60%NICD
INFLUENZA PANDEMICS
1510 1889 – 1890 H2N2 1899 – 1900 H3N2 1918 – 1919 H1N1 “Spanish flu” 1957 – 1958 H2N2 “Asian flu” 1968 – 1969 H3N2 “Hong Kong flu”
1977 H1N1
SEASONAL INFLUENZA 250 – 500,000
DEATHS
> 50 million> 1 million~ 0.5 million
MILD
NICD
INFLUENZA PANDEMICS
NO. OF WAVES
1889 – 1890 H2N2
1899 – 1900 H3N2
1918 – 1919 H1N1 2 or 3
1957 – 1958 H2N2 3
1968 – 1969 H3N2 2
NICD
… … a lot of “known knowns; a lot of “known knowns; there are things we know there are things we know we know. We also know we know. We also know
there are known unknowns; there are known unknowns; that is to say we know there that is to say we know there are some things we do not are some things we do not know. But there are also know. But there are also unknown unknowns – the unknown unknowns – the ones we don’t know we ones we don’t know we
don’t know”don’t know”Donald Rumsfeld Donald Rumsfeld
US Secretary of DefenseUS Secretary of Defense
THE IMPONDERABLES - VIRAL
1. ? Further waves
2. ? Replace human seasonal H1N1
3. ? Reassort with human seasonal H1N1
4. ? Mutational resistance development
5. ? Reassort with human seasonal H3N2
6. ? Reassort with avian H5N1
NICD
THE IMPONDERABLES - HUMAN
1. Travel
2. Urbanization
3. Immunosuppression
4. Displaced persons
5. Medical and scientific advances
NICD
THANK YOUTHANK YOUTHANK YOUTHANK YOU