Page 146 - TBE_Book_V2_2019

Chapter 7: TBE in special situations

adsorption of TBEV in the human gut takes from 1:200 to < 1:1000. Estimating the
33
place in the duodenum, and moreover, TBEV number of reported TBE cases proportional to
seems to be protected by milk proteins during the number of visitors to TBE endemic areas in
the stomach passage with its acid conditions, Europe, there is an estimated risk of infection
finally infecting duodenal cells. of 1:77,000 to 1:200,000 travels in TBE
23
endemic areas. The risk depends on the time

of travel (e.g. summer vs. winter), the
TBE as travel risk duration of the travel and the risk activities
24
during traveling. The real number of travel-
associated TBE infections is underreported for
TBE is endemic in some of the most popular
holiday destinations in Europe. In six of the 10 many different reasons, most importantly lack
most visited countries TBE is endemic at least of awareness and under-diagnosing in non-
25,26
endemic areas.
in some areas (Figure 2), including Austria and
Scandinavia. In Germany about 2 to 6% of the Travel-related cases in non-endemic countries
annual TBE cases are acquired abroad (Robert have been reported during recent years from
Koch Institut Jahrbuch 2006 - 2017). Countries Israel, the Netherlands, Australia, United
where Germans acquire TBE outside their own States and England. The Australian patient
territory are ranked by frequency in Figure 4.
travelled by car from Moscow to Novosibirsk
with ample opportunities for exposure in

Figure 4: Origin of travel-imported nature although it was unclear whether he
TBE cases in German patients was infected by a tick bite or by the alimen-
tary route. He developed a generalised
infection with drowsiness, fatigue and lower
27
limb myalgia. Two Germans from Baden-
Württemberg, father and son, acquired their
TBE infections during a travel rest by drinking
goat milk and eating goat cheese in
13
Zwiefalten, southwestern Germany. The
infection of the son was diagnosed several
days later when back again in London, UK,
where he was employed. The infection of the
father was only diagnosed in Germany after
the diagnosis of the son was available. French
physicians reported a number of TBE cases
acquired outside of the country, mainly on the
other side of the Rhine River in the Black
Forest in Germany. Single travel-related TBE
cases have also been reported from Austria,
28
Russia, Czech Republic and Sweden. While
recently the first autochthonous TBE cases
29
were reported from the Netherlands, the
According to the Epidemiologische Bulletin
2007 to 2017; RKI greater proportion of TBE cases diagnosed in
the Netherlands are still imported cases in
22
According to Süss the risk of infection for travellers. TBE infections are imported to the
TBE after a tick bite in endemic areas varies Netherlands mainly from Germany and from
30,31
according to the respective human activity Austria.

141
141