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Chapter 12b: TBE in Latvia

Vaccination is mandatory for employees with Currently used vaccines in Latvia are FSME-
high risk of occupational exposure such as Immun® (TicoVac, used since 1995) and
forest workers, military personnel, and lab Encepur® (since 2001 for adults and 2002 for
workers and is paid by the employer. For children). FSME-IMMUN® is the most common
other residents of Latvia and travellers used TBE vaccine in Latvia, having up to an
vaccination is also strongly recommended, but 86% market share in those vaccinees who
not reimbursed, but most of the private received at least one dose of TBE vaccine and
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insurance companies covers TBE vaccine knew which brand they received.
expenses. 13,14 Because of National Nevertheless, the number of vaccination
Immunization Program, TBE vaccination doses sold annually should be cautiously
coverage in children reached up to 77% in correlated to percentage of vaccinated
highly endemic areas and 22% nationwide, population, because exact vaccine usage at
reducing proportion of TBE cases among individual level remains unclear and cannot be
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children from 12.5% in 2001 to 3.6% in 2010 equalized with the sales amount.
and 2016. For whole population vaccination
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rate was 39% in 2009 and increased up to
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52.5% in 2015.
Overview of TBE in Latvia

Table 1: Virus, vector, transmission of TBE in Latvia

In Latvia, all 3 main TBEV sub-types circulate: European, Siberian,
and Far Eastern.
Viral subtypes,
distribution 4,5,6 In Latvia 1-96 is a close relative to the Vasilchenko strain (Siberian sub
-type), and RK1424 is related to the Sofjin strain (Far Eastern sub-
type).
Among the small rodents identified in the most long-term monitoring
site for I. ricinus (Riga region) in 1997–2001 were Clethrionomys
Reservoir animals
glareolus (85%), followed by Sorex araneus, Apodemus flavicollis,
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and Apodemus agrarius.
I. ricinus ticks are spread throughout the western and central parts of
Latvia; however, they are also present in small numbers in the
eastern part of the country. I. persulcatus solely dominates in the
eastern part of the country, comprising 58%–99% of all collected
ticks.
Infected tick species (%) 3,6,7
Earlier data reveal that TBEV annual prevalence from 1993 to 2002 in
the field-collected adults for I. ricinus adults varied between 1.7% and
26.6% and for I. persulcatus – between 0% and 37.3%. The infection
level in ticks removed from humans was much higher and from 1998–
2002 reached about 30%.

Dairy product transmission Not available

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