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: cdcinfo@cdc.gov 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