Data collection systems and

ad-hoc data collections

Bruno Lina

Hospices Civils de Lyon, CNR des virus influenza,

Université de Lyon, Lyon, France

What do we know about influenza ?

• It is a disease (and a virus) with a worldwide impact

• It has a wide range of impacts on individuals (risk-factors, clinical presentations)

• It can change every year and may be responsible for pandemics

• Its surveillance is a worldwide approach based on the collection of both epi and viro data

• Different approaches have been used

• The most consistent data is provided by networks that can provide good clinical and virological data (beware of confounding pathogens and misinterpretation of the results).

Influenza: a viral respiratory disease to be

reported in in- and out-patients

Le virus pénètre dans l’organisme

via le nez, la bouche et les yeux

Types and sub-types of human influenza

viruses

Type B

H1N1 H2N2 H3N2 H?N?

Type C

Type A

Usual trends of influenza activity

• Influenza is responsible for epidemics

• Influenza can be circulating all year round

• Influenza is unpredictable

• One must keep in mind that a pandemic virus will

emerge in the future

Clinical surveillance

How to detect flu in a patient

Patient

Généraliste /

Pédiatre

Clinical syndrome:

ARI – ILI

Clinical form? Virological

testing

Laboratoir

e

Test Rapide

ou

Report of clinical surveillance: ARI vs ILI

0

50

100

150

200

250

semaines de surveillance entre 2001 et 2004

IRA/Actes MG base 100

IRA/Actes Ped base 100

40 50 1 5 15/40 45 52 7 15/40 45 50 5 15

2001-2002 2002-2003 2003-2004

Weekly report of ARI by GP and pediatricians of the GROG influenza network

Example: collection of ARI data in France (2001-04)

Influenza : estimating impact through disease

(P&I) surveillance in the US

Different seasonal patterns of influenza circulation

Tamerius et al;,Environ Health Perspect ,2011

Clinical surveillance of Influenza

• Can be based on community and hospital surveillances

• Can be done through ARI or ILI surveillance

• Should be carried out all year round in tropical areas

• Clinical activity should be reported on a weekly basis

• Age-groups surveillance should be implemented

• Additional items can be reported depending if detailed clinical data

is collected

Virological surveillance

Virological surveillance of influenza:

an added value to clinical surveillance

Le virus pénètre dans l’organisme

via le nez, la bouche et les yeux

Influenza, a short lasting disease

Sample Day 6 negative

Rapid test

Culture

PCR

BD Directigen EZ Flu A+B

NOW INFLUENZA A&B

ESPLINE

Influenza, a less short lasting disease in children

Report of influenza detection by labs: ie in France

(combined hospital and community detection)

Virus type/subtype dominance

sentinel vs. non sentinel

The need for virological data

to avoid confounding factors

• Other pathogens (if not detected)

– RSV

– Rhinoviruses

– Others…

• Diagnostic methods

– Rapid tests

– Molecular testing

• Surveillance system

– Impact of age groups

– Hospital-based or community-based surveillance

Clinical specimens and virological data

?

RSV circulation in different latitudes

Virus type/subtype dominance sentinel vs. non sentinel

Integration of Clinical and Virological

Surveillances

Number of ARI observed by age groups

0

100000

200000

300000

400000

500000

600000

700000

800000

1 2 3 4 5 6 7 8 9 10

WEEK

ARI 0-4

ARI 5-14

ARI 15-64

ARI >=65

Incidence of ARI by age groups and by week

Consultations pour IRA (/ 100 000) par groupe d'âge

0

1 000

2 000

3 000

4 000

5 000

6 000

7 000

8 000

9 000

10 000

2 3 4 5 6 7 8 9 10

Week

Ta

ux

0 to 4 5 to 14 15 to 64 >65

Estimation of GP consultations for influenza in France

Estimation du nombre de grippe confirmée

(Au total de la semaine 2 à la semaine 10 : 1 702 393)

IC95%= [1 095 041 - 2 313 893]

0

100 000

200 000

300 000

400 000

500 000

600 000

700 000

1 2 3 4 5 6 7 8 9 10

Semaine

Between week 2 and 10 : 1 702 393

IC95% = [1 095 041 – 2 313 393]

Distribution of confirmed cases per age groups

Estimation du nombre de consultations pour grippe confirmée par classes d'age et par semaine

0

50000

100000

150000

200000

250000

300000

1 2 3 4 5 6 7 8 9 10

Semaine

Nombre de grippe0-4 ans

Nombre de grippe5-14 ans

Nombre de grippe15-64 ans

Nombre de grippe>=65 ans

Incidence of GP consultation for virologically confirmed influenza by age groups

GP consultation for confirmed influenza by age groups

0

500

1 000

1 500

2 000

2 500

3 000

2 3 4 5 6 7 8 9 10

Weeks

Ta

ux

0 to 4 5 to 14 15 to 64 >65

Overall

• Influenza is all over the world, with different epidemic patterns according to latitudes

• Influenza surveillance can be carried out by differents approaches

• Integrated clinical and virological surveillance is providing the most accurate picture

• Should combined hospital- and community-based surveillances

• Confounding factors must be kept in mind to avoid misinterpretation of the data collected by the system

• This surveillance may provide a wide range of data, but should be structured together with influenza labs

• Installed surveillance for seasonal influenza is a pre-requisite for efficient surveillance in a pandemic