Food-related
illness is common world-wide, and bacterial pathogens have historically
been associated with this mode of transmission. In recent years, however,
it became clear that the majority of such outbreaks are caused by viruses,
especially the human caliciviruses belonging to the genus Norovirus
(NV, previously named Norwalk-like viruses). Transmission of these viruses
is primarily from person to person, but numerous examples illustrate
that NV are efficiently transmitted via food, water, or contaminated
environmental surfaces. NV similar but not identical to the human strains
have been found in cattle and in pigs. Different variants co-circulate
in the community, but occasionally shifts occur, in which a single variant
dominates. It was found that norovirus outbreaks occur internationally,
and that (international) food and waterborne transmission may play an
important role in the dissemination of new variants. The detection of
4 novel (recombinant) viruses in the course of the past 3 years, associated
with increased burden of illness, and in the absence of robust control
measures for viral contamination of food and water, stresses the need
for surveillance.
This project
will help build capacity across Europe for national and transnational
surveillance of outbreaks due to Noroviruses, particularly outbreaks
associated with contaminated foods, water, and environmental exposures.
This information is essential for acute control and long term prevention
of norovirus outbreaks and to inform and promote best practice. In contrast
to other disease specific networks, the EC can not rely on data aggregation
of laboratory test reports from individual sick patients at the national
level, because methods for norovirus detection are not used routinely
in many countries. While epidemiological criteria can be used to identify
outbreaks of illness due to noroviruses (as piloted in the FBVE project),
the lack of underpinning laboratory data would result in a surveillance
activity of little value for early warning purposes. Timely strain characterisation
is essential for detection of emerging novel viral strains and to provide
an early warning for the emergence of more aggressive strains. Therefore,
this project seeks to build on the highly successful collaboration achieved
by the Food Borne Viruses in Europe (FBVE) project in which national
expert virology and epidemiology combined to strengthen competence in
norovirus outbreak detection and control, and develop the necessary
laboratory tools and databases. In this proposal we will seek further
partners in existing member states and applicant countries, so extending
EU surveillance and will build competence through training in surveillance
epidemiology and in viral diagnostic methods.
