Upload
others
View
4
Download
0
Embed Size (px)
Citation preview
Patterns of Seasonal Influenza in New Zealand
Lance JenningsClinical Virologist, Canterbury Health Laboratories
3rd New Zealand Influenza Symposium, Wellington, 2nd November 2016
Outline
SESSION 1: The big picture
• Periodicity & seasonality of influenza• Surveillance & it’s public health role• 2016 season• The Canterbury influenza initiative
• & use of surveillance data
141 WHO National Influenza Centres in 111 countries (>92% population)5 WHO Collaborating Centres for Influenza (human), one for animal13 H5 Reference Laboratories4 Essential Regulatory Laboratories (FDA, TGA, NIBSC, NIID)
Coordinated by WHO Global Influenza Program in Geneva
AtlantaLondon
TokyoBeijing
Melbourne
Memphis
(GISRS)
Influenza surveillance – the bigger picture:fulfilling a public health role• Indicate the onset, size and duration of influenza activity,
• including the demographics of the population affected• Identify the influenza strains for planning future vaccines• Serves as a global alert mechanism for emergence of influenza viruses with pandemic potential
• Help to understand the impact on the health of individuals and on the health system as a whole
• Help to estimate the burden of disease to inform policy and research on • Where to target interventions – prevention and treatment• The likely benefits from effective interventions
• Acts as a marker for measuring the effectiveness of vaccines and other interventions
Understanding the impact of seasonal influenza
SYNDROMIC LABORATORY
Global, Northern & Southern Hemisphere activity: WHO Flunet
http://www.who.int/influenza/gisrs_laboratory/flunet/charts/en/
Southern Hemisphere
Northern HemisphereGlobal 2015‐2016
H3H1
New Zealand specimens positive for influenza: WHO Flunet
http://www.who.int/influenza/gisrs_laboratory/flunet/en/
0
100
200
300
400
500
600
700
92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16
Rate
per 1
00,000
pract
ice po
pulat
ion
Year
ILI and laboratory surveillance 1990‐2016
Source: Huang S. ESR, 2016; https://surv.esr.cri.nz/PDF_surveillance/Virology/FluAnnRpt/Influenzasurveillance2014Final.pdf
15 1665 9435 6
Laboratory surveillance: influenza viruses
Influenza A• A(H3N2): dominant 15/20 seasons
• A(H1N1)pdm09: 2009, 2010 and 2014
Influenza B• B/Victoria: 3‐yearly cycle during 2002‐2011
• 2015 B/Yam & more B/Victoria in late season
2016• 94% Influenza A• A(H3N2) dominant & little B: B/Yam > B/Vic
0
500
1000
1500
2000
2500
3000
3500
4000
Num
ber o
f inf
luen
za v
iruse
s
Seasonal A(H1N1)
A(H3N2)
A(H1N1)pdm09
97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16Seasonal A(H1N1) 8 48 0 52 87 1 0 0 18 13 42 2 20 0 0 0 0 0 0 0A(H3N2) 92 52 100 48 13 99 100 100 82 87 58 98 2 1 80 86 74 26 98 78A(H1N1)pdm09 0 0 0 0 0 0 0 0 0 0 0 0 78 99 20 14 26 74 2 22
0
100
200
300
400
500
600
700
800
900
1000
1100
Numb
er of
influe
nza v
iruse
s
B-Victoria lineage
B-Yamagata lineage
90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16B/Victoria lineage (%) 0 0 0 0 0 0 0 0 0 0 0 0 99 33 2 82 60 1 77 0 100 98 16 2 4 51 42B/Yamagata lineage (%) 100 100 100 100 100 100 100 100 100 100 100 100 1 67 98 18 40 99 23 0 0 2 84 98 96 49 58
Source: Huang S. ESR, Oct 2016
Influenza A
Influenza B
Influenza surveillance 2016SARI
SARI case demographics
ILI and influenza incidence
https://surv.esr.cri.nz/PDF_surveillance/Virology/FluWeekRpt/2016/FluWeekRpt201639.pdf
3C.3a
H3N2
Source: Melbourne WHOCC AIVC Report 13 Oct 2016
A(H3N2)
Source: Melbourne WHOCC AIVC Report 13 Oct 2016
DHB ILI consultations
https://surv.esr.cri.nz/PDF_surveillance/Virology/FluWeekRpt/2016/FluWeekRpt201639.pdf
Community ILI rates (per 100,000 practice population) & influenza identifications
National ILI and influenza incidence CDHB ILI CDHB influenza isolates
Influenza 2016 ‐ 91% A(H3N2)Influenza B – 81% B Yam
Canterbury: markers of influenza severity
0
100
200
300
400
500
12 16 20 24 28 32 36 40Week
Elderly Paeds Adult Elderly 2015 Paed 2015 Adult 2015
Elderly 2016
Elderly 2015
0
0.4
0.8
1.2
1.612 16 20 24 28 32 36 40
Week20162012‐2015 average
Weekly hospital admissions
ICU/CICU admissions (Weekly ave of previous 6 weeks admissions)
Cumulative rate /100,000 by age
2016 admissions to ICU approx. 2X 2015
http://intel.phuserver.org.nz/influenza‐and‐respiratory‐pathogens.aspx
Normal Workload
Increased ILI/Respiratory Illnesses
Business as Usual
Approx 4 months Approx 4 months Approx 4 months
Practice Capacity
Expanded Practice Capacity
Impact of Annual Winter Illnesses 2016 Primary Care Flu Response Plan
Staff
ILI
Non‐ILI
The Canterbury initiative
• Intel is circulated weekly to all GP’s
• One pager• Contains key points & relevant advice to GP’s
Canterbury initiative: use of influenza intelInfluenza surveillance is used to inform the Canterbury response:• GPs are made aware of
• ILI rates, ED attendances and potential pressure on hospital beds, ICU admissions• GPs advised to introduce clinic access strategies
• The holding flu clinics; Extension of opening hours. • CDHB considers funding for patients to attend clinics at after hours centres • Promote influenza vaccination
• For the funded groups as well as others; Promote workplace vaccination.• Promote respiratory hygiene in schools, preschools and community. • Highlight the role of Tamiflu in general practice.• Community messaging about self‐management (balance against the risk of the elderly, and others, presenting late and requiring hospitalisation).
• Influenza surveillance data needs to be:• Timely• Relevant to the community that uses the data for influenza prevention and control strategies.
Christchurch in bed with the ‘Flu
Thank you