Methods for sentinel virological surveillance of influenza in Europe - an 18-country survey.

The European Influenza Surveillance Scheme (EISS) is based on an integrated clinical and virological surveillance model. To assess the comparability of virological data, a questionnaire was sent to participants in June 2002 enquiring about specimen collection, laboratory diagnosis of influenza and tests for other respiratory infections. The results showed differences, but also uniformity in virological data collection methods. Similarities were reported for the specimen collection procedures; the type of swab and the transport conditions were comparable. The diagnostic methods were diverse; differences were seen in the (sub)typing methods, with PCR used most often in western countries. The findings will be helpful for the interpretation of virological data collected by sentinel physicians and for the creation of a Community Network of Reference Laboratories for Human Influenza in Europe. Important objectives of the Community Network include the harmonisation of virological methods and the application of quality assurance assessments for the national reference laboratories.