Tick-borne encephalitis virus – a review of an emerging zoonosis

Abstract

During the last 30 years, there has been a continued increase in human cases of tick-borne encephalitis (TBE) in Europe, a disease caused by tick-borne encephalitis virus (TBEV). TBEV is endemic in an area ranging from northern China and Japan, through far-eastern Russia to Europe, and is maintained in cycles involving Ixodid ticks (Ixodes ricinus and Ixodes persulcatus) and wild vertebrate hosts. The virus causes a potentially fatal neurological infection, with thousands of cases reported annually throughout Europe. TBE has a significant mortality rate depending upon the strain of virus or may cause long-term neurological/neuropsychiatric sequelae in people affected. In this review, we comprehensively reviewed TBEV, its epidemiology and pathogenesis, the clinical manifestations of TBE, along with vaccination and prevention. We also discuss the factors which may have influenced an apparent increase in the number of reported human cases each year, despite the availability of effective vaccines.

Alkhurma Hemorrhagic Fever Virus

“…AHFV'nin bulaşında ise kenelerin daha çok vektör olarak rol oynadığı düşünülmektedir [20] . Ornithodoros savignyi ve sert kene Hyalomma dromedarii virüsün taşınmasında vektör görevindedir [21] .…”

Viral encephalitis in travellers

“…4 Tick-borne encephalitis (TBE) virus is endemic in a large geographical area spanning from northern China and Japan through far-eastern Russia and into Europe, and causes thousands of cases of TBE per year in Europe alone. 5 Outbreaks of chikungunya virus have been reported in several African countries, the Indian subcontinent and South-East Asia, 6 and an outbreak was recently reported in Italy. 7 Whilst rare, neurological complications from this infection have been reported.…”

Encephalitic Flaviviruses

“…While several different species of tick have been found to be biologically competent to transmit Tick-borne encephalitis virus in the laboratory, in nature, because of specific ecological limiting factors, only Ixodes ricinus in Europe, and Ixodes persulcatus and Haemaphysalis concinna in Russia, appear to play a significant role in the virus maintenance (Labuda & Randolph, 1999). There are three subtypes of Tick-borne encephalitis virus, the European (also known as Central European encephalitis virus), Siberian (also known as west-Siberian encephalitis virus) and Fareastern (also known as Russian Spring/Summer encephalitis virus), in which the degrees of virulence are different (Mansfield et al, 2009). Transmission of Tick-borne encephalitis virus through raw milk or cheese from goats, sheep and cows was previously responsible for 10 to 20% of cases of Tick-borne encephalitis virus transmission in central Europe.…”