Page 372 - TBE_Book_V2_2019

Chapter 12b

TBE in Romania

Lidia Chitimia-Dobler, Adriana Hristea, Wilhelm Erber
and Tamara Vuković Janković

History and Current Situation

Based on an epidemiological survey per- testing 5,063 sera from humans and 2,336
1
formed, human TBE - virus neuroinfections sera from animals derived from a total of 20
may have an endemic emergent course, and counties all over Romania during the years
natural foci are in full territorial expansion. 1985 to 1993. The overall sero-prevalence rate
Identified risk areas are Tulcea district, was found to be 6.5% for humans and 10.0%
Transylvania, at the base of the Carpathian for animals with ranges from 0 to 19.4% for
2,3
Mountains and the Transylvanian Alps. TBE individual counties. The testing was done
is notifiable disease since 1996. Surveillance of using hemagglutination inhibition testing
TBE is not done at the country level, only without further confirmation by neutralization
7
regionally in some counties (northern/central/ test. A recent prevalence antibody study
western part, close to Hungary). The passive published in 2017, which studied by serum
surveillance system was implemented in 2008. neutralization test 519 sheep samples from 5
However, there is no regular screening and Romanian counties provided a total sero-
the relative risk of contracting this disease is prevalence rate of 15.2% with ranges from 2.0
unknown. In 1999, an outbreak of TBE in to 27.7%. The data are summed up in Table 3.
humans was recorded with a total of at least
4
38 human cases. The probable cause of the During an unpublished study from 2011-2012,
outbreak was goat milk and raw goat milk a total of 6,548 nymphs and 853 adult ticks of
products. Subsequent studies to detect TBEV the species Ixodes ricinus from the Romanian
in ticks of the affected regions resulted in a counties Alba, Cluj, Ilfov, Mures and Sibiu,
non -specified number of TBEV isolates, which including the region of outbreak in 1999, were
were described to belong to the European tested by real time-RT-PCR. All ticks were
subtype of TBEV. A publication of the found to be negative. Testing of 74 sheep sera
neighboring Republic of Moldova described by TBEV neutralization test gave 6/60 (10%)
the existence of the Far-eastern subtype of sera from sheep from Sibiu county, while all
7
5
TBEV just at the frontier to Romania. other sera were found negative. In the same
study the goat flock, which presumably caused
In 2001–2006, an epidemiological survey of the milk-borne outbreak in 1999 in the county
TBEV infection in 1,669 individuals from 11 of Sibiu was serologically tested by
Transylvanian counties showed a sero- neutralization test. 10/10 (100%) goats of the
prevalence rate in the general population of flock showed positive antibody titers for
7
0.6%; higher rates were found in at-risk TBEV.
populations: 5.8% in those living around
natural foci and up to 41.5% in those with In the period between 2006-2015 the studies
1,6
known occupational risks. undertaken has shown that the most frequent
species of ticks in Romania is I. ricinus. Three
In 2008 a sero-prevalence study was published Romanian counties were selected as ticks

367