Tick-borne encephalitis: What travelers should know when visiting an endemic country

Abstract

Tick-borne encephalitis (TBE) is an acute febrile illness with neurological manifestations that is prevalent in forested areas of moderate climate in Europe and Asia. TBE virus is transmitted by ticks and rarely by unpasteurized milk and dairy products. The disease burden is attributed mainly to resulting long-term disability, especially in individuals over 50 y of age. Currently, there is no causative treatment, but a very effective vaccination is available with a good safety profile. The vaccination requires 3 basic doses to be fully effective and regular boosters afterwards. An accelerated vaccination schedule enables a patient to reach reasonably protective titres within 3 to 4 weeks from the first injection. The risk of travel-related TBE is estimated to be less than the risk of acquiring typhoid fever while visiting highly endemic regions in South Asia, but more than the risk of acquiring Japanese encephalitis, meningococcal invasive disease, or rabies. The pre-travel risk assessment of acquiring TBE should consider known risk factors which include 1) the country and regions to be visited; 2) April to November season; 3) altitude less than 1500 m above the sea level; 4) duration of stay; 5) the extent of tick-exposure associated activities including leisure and professional outdoor activities within the endemic area; and 6) age and comorbidities of the traveler. A major challenge, however, is the very low awareness of the risk of contracting TBE in those who travel to industrialized European countries.

Tick-Borne Encephalitis Virus Vaccines Contain Non-Structural Protein 1 Antigen and May Elicit NS1-Specific Antibody Responses in Vaccinated Individuals

“…MS data were acquired using a data-dependent strategy that selected up to the top 10 precursors based on precursor abundance in the survey scan (350-2000 m/z). The resolution of the survey scan was 60,000 (400 m/z), with a target value of 1×10 6 ions, one microscan, and a maximum injection time of 1000 ms. HCD (higher-energy collisional dissociation) MS/MS spectra were acquired with a target value of 50,000 and resolution of 15,000 (400 m/z). The maximum injection time for MS/MS was 500 ms.…”

“…For example, the virus has recently been detected in the United Kingdom, which was previously considered to be a TBEV-free country [4,5]. The virus is transmitted to humans by tick bites, or less frequently by consumption of unpasteurized milk or milk products from infected goats, sheep, or cows [3,6,7]. Tick-borne encephalitis (TBE) in humans can be asymptomatic or can manifest as a self-limiting, flu-like febrile disease.…”

Tick-borne Encephalitis Virus Vaccines Contain Non-structural Protein 1 (NS1) Antigen and May Elicit NS1-Specific Antibody Responses in Vaccinated Individuals

“…MS data were acquired using a data-dependent strategy that selected up to the top 10 precursors based on precursor abundance in the survey scan (350-2000 m/z). The resolution of the survey scan was 60 000 (400 m/z) with a target value of 1×10 6 ions, one microscan, and a maximum injection time of 1000 ms. HCD MS/MS spectra were acquired with a target value of 50 000 and resolution of 15 000 (400 m/z). The maximum injection time for MS/MS was 500 ms.…”

“…For example, the virus has recently been detected in the United Kingdom, which was previously considered to be a TBEVfree country [4][5]. The virus is transmitted to humans by tick bites or less frequently by consumption of unpasteurized milk or milk products from infected goats, sheep, or cows [3,[6][7]. Tick-borne encephalitis (TBE) in humans can be asymptomatic or can manifest as a self-limiting, flu-like febrile disease.…”

Tick-Borne Flaviviruses, with a Focus on Powassan Virus

“…Also, control of small mammals (mainly rodents) should be implemented around home environments to minimize contact with putative primary vertebrate hosts, and our pets (dogs and cats) should be protected against tick bites and examined regularly to prevent tick introduction into the living space. Preventive arrangements and basic risk factors were recently reviewed (115).…”