Eurosurveillance - Volume 10, Issue 1, 01 January 2005

The study by Stefanoff et al raises two important questions concerning tick-borne encephalitis (TBE) virus infections. First, the lack of a generally accepted case definition and secondly the quality of national surveillance of TBE cases. Ideally, reported cases should be confirmed and the clinically relevant cases with central nervous system (CNS) disease should be separated from febrile cases without CNS manifestations. The surveillance of TBE in the European countries is not uniform and not always mandatory. Efforts to reach a final diagnosis, especially in less severe cases and in children, varies as well as the awareness of the disease in low endemic regions. The only relevant and stable basis for national surveillance is cases with established CNS disease, although immunity to TBE virus after less severe febrile illness is of interest on individual basis. The ratio of non-CNS disease to CNS disease is generally believed to be about three, but there are regional differences in virulence. Significantly, age related differences are basically unknown.

The incorporation of varicella zoster virus (ZVV) vaccination in childhood immunisation schedules is becoming an increasingly common option in Europe. The current study forms part of the European Sero-Epidemiology Network 2 (ESEN2) organisational analysis for VZV and describes current passive immunisation policies, as well as current and proposed active immunisation strategies, and existing surveillance systems for diseases caused by the varicella zoster virus in ESEN countries.

In 2000, the new German infectious disease control act replaced aggregate with individual case reporting. The process was facilitated by the simultaneous introduction of electronic data transfer within the public health system. Reporting laboratories have not been electronically connected to this network. A survey by means of a postal questionnaire was conducted in 2003 among 537 German medical microbiology laboratories to explore their reporting habits, preference for electronic reporting formats, and relevant software equipment. Almost 90% of the respondents indicated a reporting delay of no more than 24 hours and 45% were still manually filling in paper forms for reporting purposes. The introduction of electronic reporting formats was favoured by 74% of the laboratories although 33% were not using any microbiology-specific software and the remaining 67% listed 62 different products. Pilot projects with selected software manufacturers might help to pave the way for the implementation of a standardised electronic infectious disease reporting format in Germany.

In 2002, the internet based reporting system OSIRIS was introduced in the Netherlands and by the end of that year had fully replaced the paper-based reporting system. The objectives of OSIRIS were to improve timeliness and completeness of surveillance data on infectious diseases reported from regional to national level. We compared the timeliness of infectious diseases reported by the conventional paper-based system in 2001 with those reported by OSIRIS in 2003. Two distinct types of delay were compared: total delay: defined as time between sympton onset and reporting at national level and central delay: defined as time between regional and national reporting. Median delays between both systems were compared using the Wilcoxon Rank Sum-Test. We also compared electronic reports received via OSIRIS in 2003 to those received through the conventional system for 2001 for completeness of specific data fields. The Fisher exact test and the Mantel-Haenzel test with Yates correction were used to determine the significance of proportions of completed data fields in each system.

Central European tickborne encephalitis (TBE) is a viral disease of the central nervous system. Despite a surveillance system for TBE existing in Poland since 1970, there are no standardised case definitions and different diagnostic tests are used in various regions. The purpose of this study was to summarise four years of surveillance data using standardised case definitions. From 1999 to 2002, 607 cases of TBE were reported to Poland’s national surveillance system: 386 (63.6%) were males, 331 (54.5%) lived in rural areas, and 186 (30.6%) were between 30 and 50 years old. Of 606 diagnosed cases, 453 (74.7%) had aseptic meningitis, 109 (18.0%) had meningoencephalitis, and 44 (7.3%) had meningoencephalomyelitis. Of the 607 reported cases, 602 (99.2%) could be classified: 153 (25.4%) as confirmed, 343 (57.0%) as probable, and 106 (17.6%) as possible cases. There was a significant difference in classified cases by gender: 28.6% of male cases were classified as confirmed, compared with 19.7% of female cases (chi2= 10.48, p=0.0053). There was a significant difference in case classification by clinical diagnosis: 32.4% of cases with meningoencephalitis were classified as confirmed cases, compared with 24.7% of cases with aseptic meningitis (chi2=11.79, p=0.019). There were also significant differences in the distribution by case definition group across geographical regions. For appropriate monitoring of TBE, a uniform and valid case definition should be used in European countries. With only 25% of reported cases meeting the definition for confirmed cases, there is a need for more complete follow-up and standardised testing of suspect cases.

At the end of May 2003, the Marseilles Hospital Centre’s virology laboratory informed the French public heath institute of 5 cases of confirmed measles among young adults living in Marseilles. An investigation was conducted, consulting different community and hospital health services, to determine the virus circulation in the Provence-Alpes-Côte d’Azur (PACA) region by the southern interregional epidemiological cell. The investigation identified 259 cases: 183 clinical, 74 serologically confirmed and 2 epidemiologically linked cases. The first cases were identified during the first six months of 2003, with a peak in April. This outbreak of measles in the PACA region was favoured by poor vaccination coverage, which created groups of susceptible population. The real number of cases was probably higher than the number identified. This investigation has outlined the limitations of the measles surveillance system in France: the sentinel network had not detected any case for this period. France needs to reach the WHO objective of measles elimination by 2010 and the surveillance tools used must be those already used in the most countries that are furthest advanced in the elimination process. To reach this goal, the Direction Générale de la Santé has nominated a working group to be in charge of proposing a national plan to interrupt indigenous measles transmission in France.