Tick-borne encephalitis surveillance systems and vaccination recommendations in UE/EEA, 2009

Abstract

Tick-borne encephalitis (TBE) is an acute disease of the central nervous system caused by a virus from the Flaviviridae family. The infection, caused by one of the subtypes of TBE virus circulating in Europe, usually progresses biphasically. The first (viremic) phase often is asymptomatic or cause influenza like symptoms. Only about one third of cases progress to the second phase. The disease may present as meningitis, encephalitis, meningoencephalitis, meningoencephalomyelitis or can cause other clinical syndromes. Sequelae are reported in 35-58% of patients. There is no curative treatment for TBE. The only successful method of prevention is active immunization. The first vaccine against TBE was produced in 1937. It was the first vaccine against Flavivirus and the third vaccine against viruses in the world. In Europe two highly effective and safe vaccines are used in preventing TBE infection and its chronic consequences. They typically need three doses of primary immunization at 0-1-6 months, and booster doses every 3-5 years. In spite of presence of effective vaccine, the TBE is growing a public health problem in Central and Northern Europe. From 1974 to 2003 a 400% increase was observed in TBE morbidity in Europe. Each year about 3000 clinical cases are reported in Europe. The aim of the study was to evaluate TBE vaccination strategies and outline localization and modalities of ascertainment of TBE endemic areas in the EU/EFTA countries. The specific objectives of the study were: · Assess TBE incidence data available in countries, · Characterize surveillance systems for TBE in particular countries, · Describe existing information on TBE endemic areas, and methods of their ascertainment; · Summarize vaccination recommendations in particular countries; · Summarize methods used for immunization coverage assessment.