Introduction

The World Health Organisation (WHO) define “surveillance” as the systematic ongoing collection, collation and analysis of data and the timely dissemination of information to those who need to know so that action can be taken. In other words, the epidemiological surveillance is necessary to plan, single out, manage and evaluate the actions relevant for the management of population sanitary status. In particular, the main tasks of surveillance systems may be summarised as follows:

• to monitor the sanitary status dynamics with the aim of intervening with timely preventive measures,
• to evaluate measures already implemented in relation to disease prevention and control,
• to optimize the use of available resources.

In addition, the collection of relevant epidemiological data, through effective surveillance systems based on validated and standardized diagnostic protocols, is fundamental for any science-based assessment of the risks of pathogens introduction and/or spread in defined geographical areas.

The viral arthropod-borne zoonoses included in the present project, namely RVF, CCHF and WNF, represent an important group of infections for humans and animals, and an emerging sanitary threat in the Mediterranean Basin and in the neighbouring Countries. These diseases, being vector-borne infections, cannot be prevented through an animal trade control policy only. Moreover, the individual national measures tend to be completely inadequate and they are very often dependent on various choices made in other neighbouring Countries. It implies that medium and long terms objectives for the surveillance and prevention of RVF, CCHF and WNF spread should include the establishment of international surveillance networks embracing all countries at risk of the Mediterranean and neighbouring area.

The first steps for the development of such ambitious objectives are:

• evaluation of sensitivity and specificity of available diagnostic tests and protocols,
• collection of currently available surveillance data,
• assessment of surveillance strategies and their implementation,
• control and surveillance of efficacy of interventions.

Presently some data on diseases occurrence in the areas under study are available from the international organization (WHO and OIE), but few information may be retrieved from published papers on geographical distribution and density of vectors and vertebrate reservoirs. Relevant epidemiological information may be gathered from the results of national surveillance plans in place or monitoring activities performed in some Countries (for example, in France, Italy or Romania for WND), but these data is rarely comparable, given the different diagnostic protocols and definition of epidemiological units under study.

Description of work

The introduction, dissemination and maintenance of effective surveillance systems depend also on the availability of validated and standardized diagnostic and epidemiological tools.
The existing and new diagnostic tools will be compared and evaluated in different locations and
epidemiological settings to define the diagnostic sensitivity and specificity and their use in the context of epidemiological surveillance plans. Sampling frames and collection procedures for the different target species will be evaluated, and the estimates of the diagnostic performance criteria will be used to assess the probability of detecting the infection in the study regions at different levels of assumed infection prevalence.

Since Veterinary Services in most of the affected countries are confronted with serious budget constraints, it will be investigated the potential economic gain achievable through the application of the new diagnostic test and intervention strategies. Thus, the project will undertake an economic evaluation of the evaluated surveillance and control systems.

For a precise data analysis, farmer/owner questionnaires, wildlife services, case
morbidity/mortality rates, the age of exposure, distribution and vector dynamics will also be
determined. This will help to define the extent of surveillance (number of samples per defined time period) and the coverage of different domestic and wild animals stratified for geographical and other risk factors.

An assessment of the impact of the possible interventions will be also evaluated, to give practical indications to decision-makers on objectives really achievable and measures that could be undertaken.

During the project the establishment of a web-based geographical information system (GIS) will be evaluated, for the exchange and the dissemination of data and information of epidemiological relevance among countries.

Experts working groups will be established to in depth review the results of partners’ analysis for:
i)    the estimation of the sensitivity of the surveillance systems, considering different diagnostic protocols,
ii)    the determination of the geographical distribution of the pathogens, their vectors and hosts as well as factors promoting disease occurrence. These data will be fundamental for activities considered in WP2,
iii)    the qualitatively or quantitatively evaluation of the relative risk of vector-borne diseases in different geographical regions of the study areas,
iv)    the determination of the socio-economic impact of CCHF, WNF and RVF,
v)    the comparison of the overall surveillance costs of the surveillance systems,
vi)    the efficacy of new possible interventions, and
vii)    the creation or integration of geographical information systems for information dissemination:

• to decision-makers and for priority setting
• to the scientific community
• for public awareness