Background
Yearly fluctuation in the number of reported cases is typical for TBE and has various reasons: socio-economic, environmental and climatic changes, the circulation of the virus and reproduction in ticks and other hosts. All these factors have an impact on the risk to acquire TBE.

Early in the year, the authorities in Austria, Germany and Switzerland usually publish their TBE report about the previous year. Here, a summary of these 2019-reports is described and discussed.

Results

Austria
A total of 108 autochthonous TBE cases were reported in Austria in 2019. This was less compared to 2018, when 154 cases have been reported, but though, the number was far above the mean value of reported cases since the year 2000. The lowest number of reported cases was in 2005 (46 cases) and the highest number followed by the record year 2018 was in 2017 (116 cases).

Most patients were infected in Upper Austria (n=40), followed by Tyrol (n=21) and Styria (n=14). TBE cases have been notified from end of March to December with a peak from May to August. The youngest patient was six months old; the oldest patient was 89 years of age. More than half of the patients were older than 50 years, and 13.9% were children below 15 years of age. For 102 patients, data were available as regards severity of disease: 48% had a mild disease, 52% had a severe course of disease with meningo-encephalis/myelitis/radiculitis. Two patients died (both older than 70 years of age).

Germany
In 2019, 444 TBE cases have been reported in Germany (mostly autochthonous cases). This is 24% less compared to 2018 (584 cases). However, the yearly number of cases is fluctuating since 2001 with a minimum of 195 cases in 2001 and a maximum in 2018. The medium number of cases was 289 from 2001 until 2019.

In 52% of the cases, patients had neurological signs of disease with meningitis, encephalitis or myelitis. Two patients died (both older than 75 years of age).

46% of all cases were notified in Bavaria, followed by Baden-Wuerttemberg (37%), Saxony (7%) and Hesse (4%). Less than 2% were notified in additional five Federal States respectively. Most cases were reported from May to October. In the district „Emsland“ in Lower Saxony, which has of late been regarded a risk area, six TBE cases have been reported in 2019. The vaccination coverage is yet very low (in contrast to Austria) and the proportion of vaccinated individuals is stagnant. An increase in the vaccination rate, especially in those districts with a high TBE incidence is warranted and may prevent infections.

Switzerland
No 2019-report has been published until end of March.

The discussion about this report will be made up once published.

Discussion

In Austria and Germany (data from Switzerland yet not receivable), the number of reported TBE cases in 2019 were high – in the upper third – in the past two decades of recording. Unfortunately, the vaccination coverage remained low in Germany and is insufficient. No TBE foci have been discovered in Austria and Germany and the Swiss vaccination recommendations nearly cover the whole country, but the awareness for TBE remains unsatisfactory and may now be superimposed by the corona virus SARS –CoV-2 pandemic.

Literature
Holzmann et al.
FSME 2019 [TBE 2019]
Virusepidemiologische Information N.2 02/20
www.virologie.meduniwien.ac.at

Robert Koch-Institut (RKI)
FSME: Risikogebiete in Deutschland
[TBE: Risk areas in Germany]
Epid. Bull. 2020; 8:3-19, doi 10.25646/6510

Author: Dr. Michael Bröker

Michael Bröker is a microbiologist/biochemist by training. He has more than 35 years of experience in the field of biotechnology and vaccinology while working for various pharmaceutical companies. He also worked as curator and expert in committees of foundations, scientific boards and associations as well as for companies.

Compiled: March 2020

TBE Book