The influenza situation in Austria is monitored via the so-called Influenza Surveillance System. Data is gathered from a clinical and a virological sentinel surveillance system, in addition to data from laboratory reports on influenza detection from five other virological labs. This data is sent to the European Surveillance System, managed by the European Centre for Disease Prevention and Control (ECDC), by the Austrian Federal Ministry of Health on a weekly basis.
Clinical Surveillance
The ILI (Influenza-like illness) Sentinel System was established in 1992/93: 52 honorary, registered sentinel doctors (GPs and paediatricians) from the influenza information systems of Magistrat 15 of the City of Vienna and Department 7 of the City of Graz, as well as the Influenza Surveillance System in Greater Innsbruck, report cases of ILI identified within one working week (according to the definition of influenza-like illness) to the Reference Centre for Influenza Epidemiology on a weekly basis. The centre calculates the estimated incidence value per calendar week every week (number of reported cases per number of inhabitants in the patient catchment area of the sentinel doctors).
Virological Surveillance
Virological surveillance is conducted by the virological sentinal system DINÖ (Diagnostic Influenza Network Austria), coordinated by the National Reference Laboratory for Influenza Viruses at the Department of Virology of the University of Vienna. A total of 49 sentinel doctors send nose and throat swabs taken from ILI cases to the National Reference Laboratory for Influenza to be tested for influenza. The weekly number of samples examined for influenza and the number of those that exhibited evidence of influenza are sent to the Reference Centre for Influenza Epidemiology by the laboratory.
Five more influenza diagnosis laboratories (Virology Section, Department for Hygiene, Microbiology, Social Medicine, Med University IBK, Tyrol; Division of Virology& Infection Serology, Institute for Hygiene, Microbiology and Environmental Medicine, Medical University Graz; Microbiological Laboratory& Travel Medicine Clinic, IBK, Tyrol; Analysis BioLab GmbH, joint business of Elisabethinen Hospital Linz and AGES; SALK Labor GmbH, Salzburg ) also report their weekly sample data with the number of identified influenza cases by virus type and subtype, as well as the number of samples tested for influenza once per week.
The classification of circulating influenza viruses according to subtype carried out by the National Reference Laboratory helps identify new influenza virus varieties and allows for a comparison with the strains present in current vaccines. The objective of the Austrian influenza surveillance system is to monitor influenza activity to detect seasonal and inter-seasonal influenza epidemics early.