Comparison of virus detections reported as sentinel or non-sentinel by EU/EAA countries

Joint WHO/Europe & ECDC Annual Influenza Surveillance Meeting

Vienna, 11-13 June 2014

Number of tested specimens

Discrepancies between number of tested samples in sentinel/non-sentinel across countries:

Different populations sampled in non-sentinel across countries?

Comparability?

Non-sentinel data sources

Countries General

practices

Paediatric

practices

Polyc

linics

ICU/

critical

care

General/

internal

medicine

Paediatric

hospitals

Maternity

wards

Infectious

disease

hospital

wards

Respiratory

disease

hospital

wards

Chronic

disease

hospital

wards

Specimens

collected during

respiratory

disease outbreaks

Other

AT

BE

BG

DK

EE

GR

HU

IS

IT

LV

LT

MT

NO

PL

PT

SK

SE

IE

Percentage of flu-positive specimens by

surveillance system and week, 2010/11-

2013/14

Max. sentinel

Max. non-sentinel

Season threshold

Discrepancies in sentinel/non-sentinel overall data for season estimate:

How can non-sentinel data be used?

Number of flu-

positive

specimens by

surveillance

system, week

and (sub)type,

2008/09-

2013/14

Summary

Number of specimens tested vary between seasons and

differ between countries -> different source populations

of non-sentinel specimens?

Positivity rate in non-sentinel differs to sentinel over

weeks, lower amplitude and smaller number of week

above 10% threshold – added value for season

estimates?

Distribution of types and subtypes differ between

sentinel and non-sentinel specimens – how to interpret?

Points to be discussed

Non-sentinel data are collected differently in every country

(general practice and primary care, hospitals, ICU, outbreaks etc):

1. How should we pool the data at the Regional level?

2. What is the added value of the non-sentinel data and how can non-

sentinel data be useful?

3. Which non-sentinel data should be reported from every country?

4. How should non-sentinel data be displayed, compared and

reported in the joint bulletin?