Page 310 - TBE_Book_V2_2019

Chapter 12b

TBE in Italy

Valentina Tagliapietra, Flavia Riccardo and Giovanni Rezza

History and Current Situation

Italy is considered a low incidence country for A retrospective study conducted in 2015 in
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tick-borne encephalitis (TBE) in Europe. Areas the north east regions, allowed the
at higher risk for TBE in Italy are identification of 367 cases (0.38 per 100,000
geographically clustered in the forested and inhabitants) during the period from 2000 to
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mountainous regions and provinces in the 2013. TBE cases were mainly males (70%),
north east part of the country, as suggested and around 70% of them were between 30
by TBE case series published over the last and 70 years of age. A significant increase in
2-5
decade. A national enhanced surveillance the annual incidence rate (IR) was observed
system for TBE has been established since during the study period, from 0.18 per
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2017. Before this, information on the 100,000 in the year 2000 up to 0.59 per
occurrence of TBE cases at national level in 100,000 in 2013 (incidence rate ratio [IRR]
Italy was lacking. Both incidence rates and the =1.05 per 1 calendar year increase, 95%
geographical distribution of the disease were confidence interval [CI]: 1.02–1.08, P>0.01).
mostly inferred from endemic areas where The majority of identified TBE cases occurred
surveillance was already in place, ad hoc between April and October, consistent with
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studies and international literature. the seasonality of tick activity. Areas with IR
greater than 10 per 100,000 appear to be
TBE has been recorded in Italy since 1967, concentrated in 3 main foci: 1 in the
with foci of infection in north east (Trento, Autonomous Province of Trento (IR=41.6), 1 in
Belluno and Gorizia) and central Italy the Belluno Alps in Veneto (IR=35.9), and the
(Florence and Latina) provinces. 7-10 TBE pres- third at the extreme north east section of
ence in central Italy has not been confirmed Friuli-Venezia Giulia (IR=42.6). According to
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by further studies on ticks and serosurveys this study, the risk of TBE is associated with
conducted afterwards, 11-12 suggesting the ex- altitude, with the highest values found for
tinction of these small endemic foci. municipalities between 400 and 600 m a.s.l.,
and the IR falling along with municipality
Serological investigations of people at risk altitude decrease or increase. Of note, the IR
such as forestry rangers, hunters and
for municipalities with a mean altitude >800 m
mushrooms collectors, have been performed
a.s.l. appears to be 5 times higher than for
in order to get information on TBE virus municipalities with a mean altitude <200 m
(TBEV) circulation in the pre-alpine and alpine a.s.l..
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regions reporting seroprevalence values of
0.6%, 1.07% and 3.2% in Friuli-Venezia In 2018, the recently established national TBE
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Giulia, Trento province and Turin surveillance system recorded a total of 40
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province, respectively. Interestingly, Turin confirmed cases of neuro-invasive TBEv
province has never reported human cases of infection in four north eastern Italian regions
TBEV infection, so far. and provinces: Trento, Bolzano, Friuli-Venezia

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