Laboratory surveillance of influenza

Surveillance of influenza virus infection at the European level requires close collaboration between virologists, epidemiologists and sentinel GP networks to generate the data necessary to inform a timely public health response.
 
Physicians who participate in sentinel networks take nose and/or throat swabs from a subset of patients with influenza-like illness (ILI) or acute respiratory infection (ARI). Some sentinel surveillance systems also collect blood samples (e.g. the Czech Republic, Romania and Slovakia). The specimens are sent to the national reference laboratory and are tested for influenza viruses (if positive, subtypes are determined) and other respiratory viruses. These results are used to validate the clinical reports of ILI and ARI.
 
The national reference laboratories also report influenza test results from non-sentinel surveillance to EISN. Specimens (nose swabs, throat swabs and blood samples) can come from a wide range of sources: hospitals, non-sentinel physicians, homes for the elderly, clinics, etc.
 

Characteristics of the virological surveillance systems participating in EISN

Updated November 2013 

Country 

Location ref. lab

Primary virus detection

Virus detection: Culture eggs, type of cells

Virus detection: Additional tests A

Typing (A, B)  

Subtyping (H+N)

Variant analysis

Austria

Vienna

RT-PCR

MDCK

ELISA

HI, NAT, ELISA

HI, NAT

HI, sequencing

Belgium

Brussels

RT-PCR

MDCK

 

NAT, ELISA, other

NAT

HI, sequencing

Bulgaria

Sofia

RT-PCR

Eggs, MDCK

IF

HI, NAT, IF

HI, NAT

HI

Croatia

Zagreb

RT-PCR

Eggs, MDCK

ELISA, IF

HI, NAT

HI, NAT

 

Cyprus B

Nicosia

RT-PCR

 

 

NAT

NAT

 

Czech Republic

Prague

RT-PCR

Eggs, MDCK

ELISA other

HI, NAT, ELISA, IF other

HI, NI, NAT

HI

Denmark

Copenhagen

RT-PCR

MDCK

 

HI, NAT

HI, NAT

HI, sequencing

Estonia

Tallinn

RT-PCR

MDCK

IF

NAT, IF

NAT

 

Finland

Helsinki

RT-PCR

MDCK

other

HI, NAT other

HI, NAT

HI, sequencing

France

Lyon

RT-PCR

Eggs, MDCK, LLC-MK2

ELISA, other

ELISA

HI, NI, NAT

HI

France

Paris

RT-PCR

MDCK

ELISA

NAT, ELISA

HI, NI, NAT

HI, sequencing

Germany

Berlin

RT-PCR

MDCK

ELISA, IF other

HI, NAT, ELISA IF

HI NAT

HI, sequencing

Greece

Athens

RT-PCR

MDCK-SIAT-1

NAT, ELISA

HI, NAT, ELISA

HI, NAT

HI, sequencing

Greece

Thessaloniki

RT-PCR

Eggs, MDCK

other

HI, NAT

HI, NAT

sequencing

Hungary

Budapest

RT-PCR

Eggs, MDCK p/t-MK

IF

HI, NAT

HI, NAT

HI

Iceland

Reykjavik

RT-PCR

MDCK

IF

NAT, IF

NAT, (HI)

(HI)

Ireland

Dublin

RT-PCR

MDCK, other

IF

NAT

NAT

sequencing

Italy

Roma

RT-PCR

Eggs, MDCK

IF, other

HI, NAT, IF, other

HI, NAT, IF

HI, sequencing

Latvia

Riga

RT-PCR

MDCK

IF

NAT, HI, IF

HI NAT IF

HI, sequencing

Lithuania

Vilnius

RT-PCR

Eggs, MDCK

IF

NAT, IF

   

Luxembourg

Luxembourg

RT-PCR

MDCK

other

HI, NAT, other

HI, NI, NAT

HI

Malta C

Msida

RT-PCR

 

 

NAT

NAT

 

Norway

Oslo

RT-PCR

MDCK

other

HI, NAT, IF

HI, NAT, IF

HI, sequencing

Poland

Warsaw

RT-PCR

Eggs, MDCK

IF

HI, NAT, IF

HI, NAT

HI

Portugal

Lisbon

RT-PCR

MDCK, MDCK-Siat1

 

HI, NAT

HI, NAT

HI, sequencing, NI

Romania

Bucharest

RT-PCR

Eggs, MDCK

 

HI, NAT

HI, NI, NAT

HI, sequencing

Slovakia

Bratislava

RT-PCR

Eggs, MDCK

HI

HI, NAT

HI

 

Slovenia

Ljubljana

RT-PCR

MDCK, other

IF

HI, NAT, IF

HI, NI, NAT, IF

HI

Spain

Barcelona

RT-PCR

MDCK, LLC-MK2

IF

NAT, IF

NAT, IF

 

Spain

Madrid

RT-PCR

Eggs, MDCK, other

IF

NAT, IF

HI, NAT

HI, sequencing

Spain

Valladolid

RT-PCR

MDCK, other

IF other

HI, NAT, IF

HI, NAT, IF

HI

Sweden

Solna

RT-PCR

MDCK

 

NAT

HI, NAT

sequencing

The Netherlands

Bilthoven

RT-PCR

p/t-MK, MDCK-NBL2, MDCK-SIAT

 

NAT

NAT

sequencing, NI fluorescent assay

The Netherlands

Rotterdam

RT-PCR

Eggs, MDCK p/t-MK, other

IF

HI, NAT, IF

HI, NAT

HI, sequencing

United Kingdom

Belfast

RT-PCR

   

NAT

NAT

 

United Kingdom

Cardiff

RT-PCR

RMix Too, MDCK

/IF

NAT, IF

NAT

 

United Kingdom

Glasgow

RT-PCR

MDCK, LLC-MK2, other

IF

NAT, IF

NAT

sequencing

United Kingdom

London

RT-PCR

MDCK, other

 

HI, NAT

HI, NAT

HI, sequencing

 

Key to abbreviations

CE

Embryonated chicken eggs

ELISA

Enzyme-linked immunosorbent assay

HI

Haemagglutination inhibition assay

IF

Immunofluorescence

LLC-MK2

Lewis Lung Carcinoma – monkey kidney cells

MDCK

Madin Darby Canine Kidney

NAT

Nucleic acid amplificiation technology

NI

Neuraminidase inhibition assay

p/t-MK

Primary/tertiary – monkey kidney

RT-PCR

Reverse transcriptase polymerase chain reaction

 

Notes

A: All laboratories send a subset of virus isolates to the WHO Collaborating Centre for Reference and Research on Influenza (WHO-CC), London for confirmation and comparison with isolates from all over the world.

B: Cyprus is not an NIC and does not perform virus culture.

C: Malta is in the process of implementing virus culture.