Page 248 - TBE_Book_V2_2019

Chapter 12b

TBE in Belgium

Vanessa Suin, Bernard Brochier, Tinne Lernout,
Marjan Van Esbroeck, Steven Van Gucht and Sophie Roelandt

History and Current Situation
In 2018, the two first human tick-borne were subjected to a seroneutralization
encephalitis (TBE) cases with possible/ test. Seventeen bovines were seropositive
probable autochthonous infection, were and 6 had borderline results. The overall
diagnosed at the National Reference Centre bovine seroprevalence in the targeted area
(NRC) of Arbovirus (The Institute of Tropical was estimated between 2.61% and 4.29%.
Medicine, Antwerp, Belgium). Every year, This confirmed for the first time the
some imported cases of TBE are also detected, presence of infected foci in the wild in
infected in other European countries as Belgium.
1
Germany, Scandinavia, Austria, Kyrgyzstan or
2
Slovenia and Russia between 2011 and 2018. 3. Roe deer sera collected between 2008 and
2013 (n =190) in Flanders were examined
Moreover, several seroprevalence/prevalence for antibodies against TBEV using a
studies in sentinel animals and ticks have been seroneutralization test. Seroprevalence
performed in Sciensano. Seropositive dogs, was 5.1%.
cattle, roe deer, and wild boar have been
3-7
found in Belgium. Up to now, no positive 4. As part of a Flemish wildlife surveillance in
tick has been detected in Belgium (on a total 2013, a serological screening was per-
of ca. 1,600 ticks tested). formed on sera from wild boar (Sus scrofa;
n = 238) in order to detect TBEV- specific
1. Serum samples of Belgian dogs were antibodies by using a seroneutralization
obtained from 3 diagnostic laboratories in test. Ten wild boars were found to be TBEV
Northern Belgium (n = 688) and Southern -seropositive. This study demonstrated the
Belgium (n = 192). All samples were taken presence of TBEV-specific antibodies in
by local veterinary surgeons between wild boar and highlighted potential TBEV-
March 15, 2009 and June 22, 2009. ELISA- foci in Flanders.
positive and borderline samples were
subjected to a tick-borne encephalitis virus The above studies in animals suggest that
(TBEV) seroneutralization test. One dog TBEV has been circulating for at least several
was confirmed TBEV seropositive but the years in Belgium (at a low level), and
clinical history of the seropositive dog infections in humans were expected to occur.
could not explain beyond doubt where and In 2018, two human cases of TBE were
when TBEV infection was acquired reported, in people that were possibly/
probably infected in Belgium. However, since
2. Based on a targeted, risk-based sampling they also traveled abroad during the
design, serological screening was incubation period, the autochthonous origin
performed on Belgian cattle (n = 650), could not be confirmed.
selected from the 2010 Belgian national
cattle surveillance serum bank. All samples

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