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International influenza programs and differences from U.S.
Krista Kniss
ISDS Webinar
October 22, 2012
National Center for Immunization & Respiratory Diseases
Influenza Division
WHO Surveillance Guidelines • Epidemiologic Surveillance
– Describe the seasonality of influenza in the country. – Signal the start and end of the influenza season. – Identify and monitor groups at high risk for severe disease. – Establish baseline levels of activity for influenza and severe influenza
related disease with which to evaluate the impact and severity of each season and of future pandemic events.
– Determine influenza burden to help decision makers prioritize resources and plan public health interventions
– Provide a platform for evaluation of intervention effectiveness
• Virologic Surveillance – Identify locally circulating types and subtypes of influenza viruses and
their relationship to global and regional patterns. – Assist in developing an understanding of the relationship of virus strains
to severity – Describe the antigenic character and genetic make-up of circulating
influenza viruses. – Monitor antiviral sensitivity. – Facilitate vaccine strain selection. – Provide candidate viruses for vaccine production.
Global Influenza Surveillance • WHO Global Influenza Surveillance and Response System
– 122 National Influenza Centers (NIC) in 87 countries – 4 WHO Collaborating Centers – Tropical and resource-limited countries are underrepresented
Why might influenza burden be different/important in developing countries
• Health care access and provision is poor
• Different age structure
• Untreated comorbidities and malnutrition
• Co-infections - malaria, HIV, TB, parasitic load
• Different risk factors e.g. smoking
• Role of secondary infections (pneumococcal)
• Lower annual risk of infection?
• Higher likelihood for the emergence of a new pathogen?
• Majority of deaths will occur in developing countries during a
pandemic
J Bryce et al: Lancet 2005;365:1147-52
Disease Burden in Developing Countries
• Fewer resources means there is a need quality surveillance systems for countries to understand disease incidence and severity to help implement appropriate prevention strategies – First step to introduction of vaccine into countries
is establishing disease burden
– Most efficient (resource) way to help establish burden is through Sentinel surveillance: Influenza-like Illness (ILI) and Severe Acute Respiratory Infection (SARI) surveillance
Traditional Sentinel Surveillance (Influenza-like Illness)
• Limitation of ILI surveillance
– Provide little epi data
– Do not produce measure of disease incidence
– Focus on mild disease
Severe Acute Respiratory Infection (SARI)
• Hospital based surveillance is the most efficient way of collecting clinical information and specimens from persons with severe disease.
– Initially implemented to monitor H5N1 activity, and or the emergence of a new pathogen such as SARS.
Case Definitions
• ILI and SARI :
– An acute respiratory illness with
• history of fever or measured fever of ≥38°C
• and cough,
• with onset within the last 7 days
• And requires hospitalization.
Recommended Data Elements for SARI Patients Tested For Influenza • Unique identifier (to link epi and lab for tracking of patient) • Sex • Age • Body temperature at presentation • Date of symptom onset • Date of hospitalization (SARI) • Date of specimen collection • Seasonal influenza vaccination status • Antiviral use for present illness • Pregnancy status • Presence of chronic pre-existing medical illnesses
— Chronic Respiratory Disease — Asthma — Diabetes — Chronic cardiac disease — Chronic liver disease — Chronic renal disease — Chronic neurological or neuromuscular disease — Immunodeficiency (including HIV)
Components of U.S. and Other Countries Influenza Surveillance System
Deaths
Hospitalizations
Medically Attended
Primary Care/Outpatient Cases
Not Medically Attended
National Death Reporting, Mortality modeling
SARI surveillance
ILI/ARI surveillance
Surveys and serological studies
122 CMRS, Pediatric Death, AHDRA during pandemic and Mortality modeling from NCHS data
FluSurvNET (EIP and IHSP) AHDRA during pandemic
ILINet and ED syndromic surveillance
Surveys (i.e. BRFSS)
SARI vs. U.S. Hospital Surveillance
Enrollment Site Determination
Testing Outcome
SARI Clinical case definition
Should be a select number of good performing sites ideally representative
All cases or a unbiased systematic sample should be tested for influenza
#SARI cases per hospital admissions Proportion of SARI cases positive for influenza
FluSurvNET Medical records review for positive flu test
Participation in network (approx 7% of US population)
Part of routine care
Population based hospitalization rates
EXAMPLE OF SARI SURVEILLANCE
South Africa Influenza Surveillance Data
2009-2010
Babatyi Malope-Kgokong Presenting on behalf of the National Influenza Centre - National Institute for Communicable Diseases
(a Division of the National Health Laboratory Services)
2nd ANNUAL AFRICAN NETWORK FOR INFLUENZA SURVEILLANCE AND EPIDEMIOLOGY (ANISE) MEETING
JANUARY 11-12, 2011 ACCRA, GHANA
Methodology – SARI Surveillance
• Prospective hospital-based surveillance
• Sampling: All SARI cases daily except weekends for all sites
• Procedure: Informed Consent obtained
Conduct structured interviews
Collect: Respiratory Samples - tested by multiplex real time PCR
Blood sample - for pnuemococcal PCR and HIV PCR or ELISA
Collection of in hospital results of routine laboratory investigations
Patient followed up until final outcome
Location of SARI Sentinel Sites – South Africa, 2010
Northern
Cape
Western
Cape
Eastern
Cape
Free
State
KwaZulu
Natal
MpumalangaLimpopoGauteng
North West
500 0 500 Km500 0 500 Km
N
EW
S
Northern
Cape
Western
Cape
Eastern
Cape
Free
State
KwaZulu
Natal
MpumalangaLimpopoGauteng
North West
500 0 500 Km500 0 500 Km
N
EW
S
N
EW
S
6 Hospitals: • 1 Gauteng • 2 Mpumalanga • 2 North West • 1 KwaZulu Natal
Case Definitions - SARI Surveillance
Children 2 days
to < 3 months
old
Diagnosis of suspected sepsis
or physician diagnosed acute lower
respiratory tract infection (LRTI) irrespective
of signs and symptoms.
Children ≥ 3
months to < 5
years old
Physician-diagnosed acute LRTI including
bronchiolitis, pneumonia, bronchitis and
pleural effusion.
Children ≥ 5
years old and
Adults
Acute LRTI with:
Sudden onset of fever (>38ºC) and
Cough or sore throat and
Shortness of breath, or difficulty breathing
with or without clinical or radiographic
findings of pneumonia.
Patient presenting within 7 days of the onset of illness, Overnight Sleep
Distribution of SARI Cases by Province and
Hospital, South Africa 2009-2010
Province Hospital Total
Patient Admitted
Total SARI visits
“N (%)”
Total SARI sampled
“N (%)”
No. Influenza Positive/No.
Tested (% Flu +)
Gauteng CHBH Data
Pending for 2010
8360 5966 (71.3) 508/5966 (8.5)
KwaZulu Natal Edendale 8050 576 (7.2) 374 (64.9) 26/374 (7.0)
North West Klerksdorp 1009 188 (18.6) 91 (48.4) 14/91 (15.4)
North West Tshepong 3206 323 (10.1) 294 (91.0) 31/294 (10.5)
Mpumalanga Mapulaneng 6387 529 (8.3) 507 (95.8) 56/507 (11.1)
Mpumalanga Matikwane 8341 748 (9.0) 512 (68.4) 59/512 (11.5)
Total 26993 10724 7744 (72.1) 694/7744 (9.0)
Proportion SARI Cases Admitted by Month,
South Africa, 2009-2010
15
20
25
30
35
40
45
50 Ja
n
Feb
Mar
Ap
r
May
Jun
Jul
Au
g
Se
p
Oct
No
v
De
c
Month
% o
f S
AR
I Cas
es
pe
r A
dm
issi
on
s
Year - 2009
Year - 2010
Are we missing anything?
• Important to monitor both mild and severe disease (ILI, hospital, and mortality surveillance) – We pick-up signals through ILI and FluSurvNET – State Coordinators are in touch with local hospitals in
areas where we don’t have national hospital surveillance implemented (collected information on these during the pandemic)
• Detection of outbreaks of severe or unusual disease – Responsibility of states to investigate and report
outbreaks – ILI may pick-up signals, and laboratory data should
signal anything unusual.
Thanks. Questions???
For more information please contact Centers for Disease Control and Prevention
1600 Clifton Road NE, Atlanta, GA 30333
Telephone: 1-800-CDC-INFO (232-4636)/TTY: 1-888-232-6348
E-mail: [email protected] Web: http://www.cdc.gov
The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention.
National Center for Immunization & Respiratory Diseases
Influenza Division