|
The EUVAC-NET network is in charge of the epidemiological
surveillance and control of vaccine preventable diseases. It is coordinated
by the SSI in Denmark, in collaboration with the ISS in Italy. The two
main diseases targeted by the network are measles and pertussis. A collaboration
is planned with the PHLS for the monitoring of Haemophilus influenzae
b. EUVAC-NET includes the Member States of the European Union, and Iceland,
Norway and Switzerland.
Introduction
In September 1998, a proposal from the European Commission
was adopted as a Decision of the European Parliament and Council (1) to
set up a network for the epidemiological surveillance and control of communicable
diseases in the European Community. Based on a proposal from the Statens
Serum Institut (SSI, Denmark), an agreement was reached with the Commission
(DG SANCO) whereby the Department of Epidemiology at the SSI was to coordinate
a collaborative project, EUVAC-NET. This project undertakes surveillance
of vaccine preventable infectious diseases and involves surveillance institutions
in the 15 Euro-pean Union (EU) countries plus Iceland, Norway, and Switzerland.
The SSI should also coordinate measles surveillance whereas the Istituto
Superiore di Sanità (ISS, Italy), should coordinate the pertussis
component through an associated contract between the two institutes. It
was further agreed that surveillance of Haemophilus influenzae type b
(Hib) should be shared between the Public Health Laboratory Service (PHLS)
and the SSI.
Aims and objectives of the project are presented in table
1. Activities, outcomes, and lessons learnt from the first project period
of 18 calendar months are presented in this article.
Table 1 - Aims and objectives for the EUVAC-NET
|
Objectives
- To create a surveillance network with emphasis on epidemiological
and laboratory surveillance methods
- To operate a surveillance network for vaccine preventable infectious
diseases beginning with measles and pertussis
|
|
Tasks
- To facilitate the development of standardized surveillance methodologies
- To monitor and compare disease epidemiology and effects of different
vaccination programs
- To facilitate the development of uniform case definitions, disease
classifications and definitions of basic epidemiological and clinical
data terms with the aim of making data comparable.
- To monitor the burden of diseases from data on complications,
fatalities and sequelae; for measles especially encephalitis and
death
- To collaborate with other projects, European networks and/or
existing international surveillance systems working with aspects
relevant to the EUVAC-NET objectives
- To collate and deliver valid data also with the possibility
of detecting international epidemics and outbreaks in the EU
- To create disease specific databases
- To establish an interactive web site for the EUVAC-NET
- To create vaccination coverage databases
|
Methods
The methods of creation and operation of a surveillance
system are primarily epidemiological and managerial. A project coordinator
and a pertussis coordinator were appointed at the SSI and ISS respectively,
and each of the central surveillance institutions in the participating
countries has appointed one contact person to EUVAC-NET, the so-called
gatekeeper. The gatekeepers function as communication nodes for the network
and are familiar with their national surveillance systems, vac-cination
programmes, and methods used for estimation of vaccination coverage.
Standardised surveillance methods are developed with
respect to disease specific preventive targets and take into account differing
levels of incidence. The coordinators and/or the gatekeepers prepare proposals
to be discussed and agreed upon by the network participants. Decisions
to be taken require qualified coordination and effective communication
between the coordinators and gatekeepers, mainly through email and annual
or focused meetings with stakeholders, i.e. gatekeepers and other national
representatives as well as members of related organisations and projects
working within the same field.
Activities
Planned activities during the first project period are
presented in the figure.
Before the creation of the prototype databases and the
start of the data input for measles and pertussis for 1998 and 1999, a
questionnaire survey was carried out to assess the surveillance activities
for measles and pertussis performed at a national level in the countries
participating in EUVAC-NET.
During 1996– 1999, Hib surveillance in Europe was conducted
via a network of nine EU and three non-EU countries, coordinated by the
PHLS. From 2000, the Hib laboratory network should continue to be coordinated
in the UK while epidemiological data on Hib infection should be coordinated
in Denmark.
The process of developing an interactive web site to
be incorporated into the Health Surveillance System for Communicable Diseases
(HSSCD) in the European Public Health Information Network (EUPHIN) was
defined at a meeting with the participation of representatives from the
ISS, WHO EURO, Cap Gemini Ernst & Young, Belgium, and the SSI.
Outcomes from the first project period
It has been agreed that the WHO case definitions of measles
and pertussis (2) are used as references in EUVAC-NET (table 2).
Table 2. WHO case definitions of measles and pertussis
|
MEASLES
Clinical case definition:
Any person with:
- Fever, and
- Maculopapular rash, and
- Cough, coryza or conjunctivitis
or
Any person in whom a clinician suspects measles infection
Laboratory criteria for diagnosis:
- At least a fourfold increase in antibody titre or
- Isolation of measles virus or
- Presence of measles-specific IgM antibodies
PERTUSSIS
Clinical case definition:
A person with a cough lasting at least 2 weeks with at
least one of the following:
- Paroxysms of coughing
- Inspiratory "whooping"
- Post-tussive vomiting
- Without other apparent cause
Laboratory criteria for diagnosis:
- Isolation of Bordetella pertussis or
- Detection of genomic sequences by PCR
|
Laboratory verification of measles is essential, particularly
in the elimination phase. For pertussis any other case definition routinely
used in national surveillance systems will be accepted provided that relevant
information on laboratory diagnosis is reported (3). The definition of
a minimal data set for pertussis is more complex than for measles, for
which an elimination target is already defined (4).
Steps have already been taken to improve surveillance
(5,6), particularly regarding measles, which is generally not considered
a major threat to health in Western Europe. The network will be an added
value to the WHO strategy to eliminate measles in the European region
by 2007 and may also relieve the WHO EURO from some of the workload in
the region. Also, a substantial support in reaching the objective of controlling
pertussis diseases to less than 1 per 100 000 by 2010 should be achieved
by EUVAC-NET.
The EUVAC-NET prototype database will be compatible with
the WHO EURO Computerized Information System for Infectious Diseases (CISID)
and a close collaboration has been established with the joint aims of
avoiding double reporting and minimising the workload for participating
countries. The exchange of know-how and experience with WHO EURO has been
beneficial in the process of establishing this new surveillance network.
The collaboration is in accordance with the recently approved agreement
between the WHO and the EU to strengthen and intensify cooperation in
the development of methods for surveillance, strengthening communicable
disease surveillance, and improving responses.
In most countries the contacts in the Hib surveillance
laboratory network are different from the EUVAC-NET gatekeepers, and it
has now been agreed that both laboratory and epidemiological data on Hib
shall be collated by the PHLS in the European Union Invasive Bacterial
Infections Surveillance (EU IBIS) project. For the time being, this is
considered more feasible than splitting the Hib surveillance between two
networks.
Future collaboration has been agreed on between EUVAC-NET
and the PHLS regarding a proposal for Enhanced Laboratory Surveillance
of Measles (ELSM) by oral fluids. Epidemiological data from saliva testing
would be incorporated into the EUVAC-NET database. Furthermore, collaboration
on genotyping would be an asset when the EUVAC-NET countries enter the
elimination phase.
The outcome of the questionnaire survey is reported elsewhere
(5, 6), and the first data inputs for 1998 and 1999 into a prototype database
for measles and pertussis have been completed for testing.
At the second annual meeting in May 2001, it was recommended
that EUVAC-NET should be a forum for exchanging experience, for example
regarding methods for the strengthening of disease surveillance and the
monitoring of vaccination coverage and the coordinators should facilitate
improved communication within the network. In order to prepare focused
workshops in the next project period, each country should define three
priority areas or topics to strengthen the surveillance in the next two
years.
The three countries still without case based surveillance
of measles should consider its establishment. When more than one system
is in use, the case based system should be given priority and linking
of data to laboratory results should be enhanced. Estimation of vaccination
coverage based on birth cohorts should be encouraged in all countries.
Close monitoring of trends of pertussis should be promoted,
encouraging the implementation of case based surveillance in countries
dealing only with aggregated data. Moreover, where information on death
or hospitalisation is not included in the routine surveillance system,
an alternative data source should be identified to better assess the burden
of the disease.
When relevant, and until the Commission defines formal
rules, the principles of collaboration applying to participants in Enter-net
(7) should be used by EUVAC-NET. In view of the future extension of the
EU to the Central and East European countries (CCEE), EUVAC-NET should
link with the coordinators of a WHO EURO supported and newly established
network in these countries.
Lessons learnt
The first project period was characterised by managerial
activities related to the creation of the network, which, to a certain
extent, took longer than expected. The implementation of Community networks
such as EUVAC-NET results in additional workload for the participating
institutions, even when they avoid duplication of activities.
The creation and operation of a network are manpower
demanding at a national level when it comes to submitting and updating
data, participation in meeting activities and focused activities in the
network. This extra workload is currently not fully compensated for in
the national surveillance institutions.
The planning process would have been easier if terms
of operation between the EUPHIN-HSSCD and EUVAC-NET had been specified
from an early stage, for example type of software, placement of the database
server, maintenance, and agreed procedures. Meetings held between Cap
Gemini Ernst & Young, WHO EURO, and the EUVAC-NET were fruitful as
a forum for exchanging experience, expectations, and ideas, but did not
facilitate practical action.
The initial budget for an activity may not always meet
the actual costs, but it was a serious problem that the grant for the
first project period only covered budgeted activities in 12 of the 18
calendar months specified as the period of performance in the agreement.
Technical matters at the Commission caused this, and additional funding
was not approved as initially expected. Besides the contract period of
18 months, which already implied rather short term employment conditions,
the shortage of funds also caused difficulties in sustaining qualified
personnel in the project.
Conclusion
The first steps have been taken to create and operate
EUVAC-NET. However, ensuring high quality data and usefulness of the network
is an ongoing process, and good networking with active participation and
development of ownership will determine the success.
Managerial aspects may be similar in other networks and
networking between managers and coordinators of different networks would
facilitate the best use of experience gained in the process of creating
a community network for the epidemiological surveillance and control of
communicable diseases in the Community.
Long term planning and budgeting would be an asset to
maintain momentum in the process of creating a surveillance network. Its
sustainability will require a substantial resource commitment from the
Commission and member states in line with conclusions drawn in the Commission’s
progress report on the network in the Community (8). It is estimated that
the annual financial support to operate and further develop EUVAC-NET
will remain at the same level over the next 5-10 years, although the number
of new diseases to be included and the number of countries participating
in the network will have an impact on the budget.
|