View clinical trials related to Tick-Borne Encephalitis.
Filter by:Cases of encephalitis of varying severity have been described in recent years in eastern France involving tick-borne encephalitis virus (TBEV). The main objective is to demonstrate the presence of TBEV in Limousin, in patients with a positive Lyme serology, or a neurological picture compatible with TBEV.
Tick-borne encephalitis (TBE) is a zoonosis mainly transmitted to humans by the bite of ticks of the genus Ixodes and, to a lesser extent, by the consumption of contaminated and unpasteurized dairy products. During the last decade, the epidemiology of this arbovirosis has changed profoundly with the discovery of new human cases and/or new areas of circulation of tick-borne encephalitis virus (TBEV) throughout Europe and particularly in France. Historically, Alsace is the main endemic area for this pathology in France. The pathology is notifiable since June 2021 in France. Although TBEV infection in children seems to lead to a milder clinical presentation, data are much less abundant than in adults and only a few cases reported in infants under 1 year old have been published. Data from the most recent ECDC Annual Epidemiological Report on TBE (2019) showed incidence rates of approximately 0.2 and 0.5 per 100,000 population in patients younger than 5 and 15 years, respectively. However, several observations may moderate and challenge both the low incidence rate and the less severe clinical presentation reported in children
The main purpose of this study is to provide safety and immunogenicity data in Japanese participants.
Tick-borne Encephalitis (TBE) can be prevented by vaccine. Vaccine failure, defined as a case of TBE regardless of previous vaccination, has been described and seems to be more predominant with increasing age, suggesting a less effective immune response following with increasing age. In fact previous studies has shown a reduced antibody response in elderly individuals compared to younger when vaccinated against TBE. As a result, in Sweden, an extra vaccine dose has been recommended during the primary vaccine schedule to individuals > 50 years of age. This alternative vaccine schedule has not been tested. The investigator aim to test if an extra vaccine dose in the primary vaccine schedule for those > 50 years of age improves the immune response and offers a corresponding immunity to younger individuals following TBE vaccination.
Obese people have an altered immune responsiveness. The present study investigates whether this influences immune responses to booster vaccinations (i. e. booster vaccination with TBE vaccine "FSME Immun") and if a modification of vaccination schedules is needed. Obese adults (BMI >30) >18 - 60 years are compared with adults with normal weight (BMI <25) concerning TBE-NT- antibody titers, TBE- NT antibody titer course and cellular immunity. Metabolic parameters and sexual hormones will be tested and compared as well.
In Europe, tick-borne encephalitis (TBE) virus causing TBE is transmitted by the bite of Ixodes ricinus tick, which can also transmit Lyme borreliae , the causative agent of Lyme borreliosis (LB). Since TBE and LB are both endemic with high incidence rates in Slovenia, we should be attentive to the possibility of double infections. Double infections with TBE virus and Lyme borreliae were reported to occur rarely even in endemic countries, however reliable data on coinfection rates are rather limited. Microbiological diagnosis of TBE virus infection is quite straightforward, and there is no specific therapy for TBE available so far. This markedly differs from borrelial infection, in which case interpretation of serological test results demands more caution, but there is highly efficient antibiotic treatment available for LB. This may lead to over prescribing of antibiotics to TBE patients with documented borrelial antibodies in serum indicating possible coinfection with Lyme borreliae, but missing clinical or microbiological criteria for proven borrelial coinfection. Approximately 10% of patients who had been treated appropriately for LB and about one third of patients after TBE report nonspecific subjective complaints, such as fatigue, headache, arthralgia, and myalgia, termed post-Lyme and post-encephalitic symptoms, respectively. These may not be differentiated clearly from nonspecific symptoms occurring with a rather substantial incidence also in the general population. A trend of ascribing medically unexplained nonspecific subjective symptoms to LB in subjects with positive borrelial antibodies in serum puzzles the situation further. The aim of this prospective observational study was to assess the proportion and clinical implication of proven and possible coinfection with Lyme borreliae in patients with TBE, and to evaluate the association between anti-borrelial antibiotic therapy and clinical outcome in the subgroup of patients with possible coinfection.
In Slovenia, tick-borne encephalitis and Lyme borreliosis are both endemic diseases with high incidence rates and they are both transmitted by a bite of infected Ixodes ricinus tick. In clinical practice, tick-borne encephalitis is confirmed by demonstration of tick-borne encephalitis antibodies in serum of a patient with compatible clinical presentation and cerebrospinal pleocytosis. Patients with Lyme meningitis or meningoradiculitis also have cerebrospinal pleocytosis, however the presence of borrelial antibodies in serum does not attest Lyme neuroborreliosis. Patients with tick-borne encephalitis and positive borrelial antibodies in serum, but not fulfilling criteria for Lyme neuroborreliosis, are often being treated with antibiotics in several European countries due to the possibility of double infection. The investigators hypothesise that such patients do not benefit from antibiotics. Such an approach may appear safe regarding the possibility of borrelial infection, however it can also be associated with detrimental consequences such as antibiotic related adverse reactions, negative epidemiological impact on bacterial resistance, and intravenous catheter related complications.
In Slovenia, tick-borne encephalitis and Lyme borreliosis are both endemic diseases with high incidence rates and they are both transmitted by a bite of infected Ixodes ricinus tick. In clinical practice, tick-borne encephalitis is confirmed by demonstration of tick-borne encephalitis antibodies in serum of a patient with compatible clinical presentation and cerebrospinal pleocytosis. Patients with Lyme meningitis or meningoradiculitis also have cerebrospinal pleocytosis, however the presence of borrelial antibodies in serum does not attest Lyme neuroborreliosis. Patients with tick-borne encephalitis and positive borrelial antibodies in serum, but not fulfilling criteria for Lyme neuroborreliosis, are often being treated with antibiotics in several European countries due to the possibility of double infection. The investigators hypothesise that such patients do not benefit from antibiotics. Such an approach may appear safe regarding the possibility of borrelial infection, however it can also be associated with detrimental consequences such as antibiotic related adverse reactions, negative epidemiological impact on bacterial resistance, and intravenous catheter related complications.
The risk for tick borne encephalitis increases in Sweden. Together with an increased awareness of the possibility to acquire protection by vaccination, this has led to an increase in the number of doses of the vaccine distributed in Sweden each year - now being approximately 400.000. The first year, two doses with an interval of 1 month is recommended for the general population, followed by a third dose approximately one year later and an additional booster dose three years after the third. Preliminary results from a previous study showed a higher percentage protected (=titer at least 10) after 3 doses than after 2 doses (Rombo et al. EUDRA CT 2011 001348-31, unpublished information). In the same study, there were no differences between those who were vaccinated 0+7+21 compared to 0+30+90. The investigators were surprised to find marked differences between 2 and 3 doses also in the younger control group. The investigators therefore aim to confirm results in a new study and to add a group with a double dose at day 0 and then a single dose at day 30 and 360
Patients undergoing allogeneic blood and marrow transplantation (HSCT) experience a prolonged period of dysfunctional immunity. Systematic reimmunization is necessary at appropriate time intervals following transplantation to re-establish immunity. Vaccination practices after HSCT remain varied and data sparse. Tick-borne encephalitis (TBE) is one of the most severe infections of the central nervous system caused by a tick-borne flavivirus. There is no specific treatment, and prevention with the vaccine is the only intervention available. To assess the efficacy of TBE vaccination in adult allogeneic HSCT recipients compared to an age-matched and sex-matched control group of healthy volunteers without previous TBE vaccination, a prospective open-label phase II pilot study on humoral and cellular immune responses after use of TBE vaccine (FSME Immun) will be performed. As primary end point the outcome of the neutralization test (NT) against TBE will be assessed in a total of 26 HSCT patients one year after HSCT and in 26 healthy volunteers, namely four weeks after the second vaccination. Therefore, the number of subjects with NT titres against TBE virus >10, assumed to be the threshold for antibody-mediated protection will be evaluated. As secondary endpoints, antibody concentrations of TBE enzyme-linked immunosorbent assay before and four weeks after the second and third vaccination and antibody concentrations of NT against TBE four weeks after primary immunization. To evaluate cellular immune responses, lymphocyte proliferations assays and cytokine detection assays will be performed. In a subgroup analysis, these secondary endpoints will be compared between healthy volunteers, HSCT patients without immunosuppressive treatment and HSCT patients receiving immunosuppressive agents. Additionally, immune reconstitution by analysis of peripheral blood lymphocyte subsets and serum immunoglobulin levels will be evaluated prior to vaccination, after twelve weeks and prior to the third vaccination in HSCT patients only.