6.3. Data description and analysis

6.3.1. Overview

For some diseases there has been significant reduction in the incidence and number of cases through concerted prevention and control action by Member States (even though levels remain high in specific population segments and risk groups). For some of these diseases further joint actions (e.g. through vaccination and similar control measures) could lead to the EU, and eventually Europe, be declared ‘free’ of the disease. The fact that this can be done has been shown most recently by the WHO that declared Europe as being ‘polio free’. However, surveillance and prevention would remain necessary until the disease is eradicated, to reduce the consequences of importation of the disease.

Why this sort of vigilance is important can be deducted from the overview of trends for the 49 diseases under surveillance (Table 6.1). Of the 49 diseases, 21 have incidence levels that are in double or triple digits per million population with half of these 21 also having rising (or steady) trends. It is of concern that three of the six communicable diseases with the highest incidence in the EU belong to this group. Rising trends are also observed for the two diseases with the highest crude incidence rates in the EU (Chlamydia infection and campylobacteriosis) which could in part be due to improved surveillance. In 22 diseases the age groups most affected were those under 24, indicating that more action is needed to protect the health of our future generations. Most of the remainder (apart from TB) affect the economically active population. Of the main disease groups, the ‘Zoonoses’ and ‘Serious imported disease’ groups had the lowest incidence rates and also showed decreasing trends (except for avian influenza, AMR and malaria).

Table 6.1. Summary of general trends (1995–2005), EU incidence (2005), main age groups affected (2005), and major threats detected (2005) for diseases reported on EU-level.

The analysis of other chapters in this report also shows that across the EU there is a heterogeneity in health services organisation, in the way communicable disease prevention and control are managed and in the surveillance systems (with a consequential effect on the comparability of incidence data) not to mention inherent socioeconomic differences. Whilst the main responsibility for action lies with the Member States, EU level initiatives can assist in providing the evidence base for action, in identifying and sharing best practice, and in suggesting methods for follow-up of interventions made. Also more and better data and scientific studies are needed to clearly understand the relative importance of the different disease areas.3

Most of the information will continue to rely on data from routine surveillance in the Member States. In order to interpret these data properly, one must realise that the original function of national surveillance systems was the detection of outbreaks and not the production of  data for more in-depth analysis of risk factors, determinants, or burden of disease. Furthermore, most routine surveillance systems are built on the paradigm that a person is infected, falls ill, goes to see a doctor, is diagnosed, and finally the case is notified. For a large number of diseases under EU-wide surveillance, this ‘classical’ view does not hold at all: HIV, Chlamydia infection, hepatitis C, toxoplasmosis, to name just a few, are often discovered by the laboratory in asymptomatic patients either by chance, as a more or less unexpected finding in a medical investigation, or as part of a screening programme. For many of the diseases discussed in this report, national incidence figures thus often reflect activity to find asymptomatic patients rather than reflecting the ‘true’ incidence of an infection.

This shift from a ‘clinic-based’ to a ‘laboratory-based’ surveillance has important implications. One is that the laboratory capabilities of the Member States must be brought up to the same level, another is that we need ‘denominator data’ for a number of such asymptomatic infections; in other words, we need to know the number of tests performed, not just the number of tests found positive.

The annual costs for health services for treating communicable diseases are significant, as indicated by country-based estimates. For example, in England, from GP consultations and hospital admissions, the costs related to communicable diseases have been estimated at around 5.3 billion €, increasing to around 7.2 billion € when the two major areas of HIV/AIDS and hospital-acquired infection treatment are included. Also, a recent study in the Netherlands has estimated annual costs based on both the direct health service costs and indirect costs (i.e. the impact on sectors other than health). This study showed that for the Netherlands (population of 16 million) in 2004 the cost attributable to norovirus was € 25.0 million, to campylobacteriosis €22.3 million, to rotavirus € 21.7 million and to salmonellosis € 8.8 million. Extrapolated to the EU level these country estimates indicate annual costs in the EU of the order of billions of euro.

Besides the direct and indirect annual costs, the last decade saw high profile crises such as SARS and avian influenza. In a globalised world, the overall consequences of communicable diseases can be very severe and instantaneous, affecting many countries and sectors other than health. The 2003 SARS outbreak cost some countries about 1% of their economies, primarily through lost tourism and travel revenues. In the case of pandemics, no part of society and no country is immune. Country-specific outbreaks (vCJD and avian influenza) have also shown the huge impact on specific sectors (especially in the food and agricultural sectors) with costs around €10 billion per episode in some countries.

The visible impact of these communicable diseases on the:

·         health of present and future generations;

·         annual and continuing costs to the health and related sectors; and

·         health and cost consequences of recent high profile outbreaks,

has given a new impetus, importance and urgency to effective disease surveillance, prevention and control: not only within countries but also to collaboration between countries and between the relevant and concerned sectors.