Tick-Borne Encephalitis, Lombardy, Italy.

Tick-borne encephalitis was limited to northeast portions of Italy. We report in Lombardy, a populous region in the northwest, a chamois displaying clinical signs of tickborne encephalitis virus that had multiple virus-positive ticks attached, as well as a symptomatic man. Further, we show serologic evidence of viral circulation in the area.

Early outcomes of endovascular repairs of the aortic arch using thoracic branch endoprosthesis.

OBJECTIVE: The only commercially available thoracic branched endoprosthesis (TBE) for treatment of the aortic arch was released in 2022. Limited data outside of clinical trial results have been reported. This study describes the demographics, anatomic details, and outcomes for patients treated for zone 0 to 2 using TBEs outside of a clinical trial. METHODS: All patients treated using TBEs for zone 0 to 2 were included. Patients treated as part of the clinical trial for zone 0 to 1 (n = 6) were excluded. Patient demographics, comorbidities, anatomic and operative details, and outcomes were reported. Outcomes and survival were then compared between groups. RESULTS: Of 40 patients, six patients underwent repair of zone 0, three of zone 1, and 31 of zone 2. There were no differences in demographics, comorbidities, or operative details by zone of treatment; however, the frequency of genetic aortopathy differed (zone 0: 0%; zone 1: 67%; and zone 2: 6.4%; P < .01). Seventy-three percent of patients were treated for dissection vs 27% with isolated aneurysms. Of the patients, 2.5% were treated for rupture, 22% were treated for symptomatic aneurysms, and 75% were treated electively. Forty-eight percent of repairs included a proximal cuff, and 83% received distal extension. Technical success was achieved in 100% of patients. Mean fluoroscopy time was 18 minutes, and median fluoroscopy dose was 416 mGy. Sixty percent of patients had prior aortic ascending/arch repair. TBE was planned as part of a complete thoracoabdominal repair in 45% of patients. Thirty-day mortality was 2.5% overall, with a single death in a zone 0 patient that occurred at day 1 due to a myocardial infarction. There were no reinterventions within 30 days. All other outcomes were similar. The 30-day stroke rate was 5.0%. The strokes occurred at day 6 (zone 1) and day 15 (zone 2); however, both were due to occlusion of a prior proximal surgical bypass and unrelated to the TBE side branch or embolization. Specifically, both patients had occlusion of a branch of their prior zone 1 or zone 2 arch replacement. An endoleak occurred in 7.5% of patients at 30-day follow-up (type II: 5.0%; unknown: 2.5%). At a mean follow-up of 6.6 months, 100% of side branches were patent. CONCLUSIONS: Repair of the aortic arch including TBE can be performed electively and urgently with acceptable stroke and death rates. TBE provides a valuable tool for patients requiring complete repair of a thoracoabdominal aneurysm. Continued investigation is underway to assess long-term safety and efficacy outside of the clinical trial.

Tick-borne encephalitis virus transmitted singly and in duo with Borrelia burgdorferi sensu lato and Anaplasma phagocytophilum bacteria by ticks as pathogens modifying lipid metabolism in human blood.

BACKGROUND: Ticks are vectors of various pathogens, including tick-borne encephalitis virus causing TBE and bacteria such as Borrelia burgdorferi sensu lato and Anaplasma phagocytophilum causing e.g. viral-bacterial co-infections (TBE + LB/HGA), which pose diagnostic and therapeutic problems. Since these infections are usually accompanied by inflammation and oxidative stress causing metabolic modifications, including phospholipids, the aim of the study was to assess the level of polyunsaturated fatty acids and their metabolism (ROS- and enzyme-dependent) products in the blood plasma of patients with TBE and TBE + LB/HGA before and after pharmacotherapy. METHODS: The total antioxidant status was determined using 2,20-azino-bis-3-ethylbenzothiazolin-6-sulfonic acid. The phospholipid and free fatty acids were analysed by gas chromatography. Lipid peroxidation was estimated by measuring small molecular weight reactive aldehyde, malondialdehyde and neuroprostanes. The reactive aldehyde was determined using gas chromatography coupled with mass spectrometry. The activity of enzymes was examined spectrophotometrically. An analysis of endocannabinoids and eicosanoids was performed using a Shimadzu UPLC system coupled with an electrospray ionization source to a Shimadzu 8060 Triple Quadrupole system. Receptor expression was measured using an enzyme-linked immunosorbent assay (ELISA). RESULTS: The reduced antioxidant status as a result of infection was accompanied by a decrease in the level of phospholipid arachidonic acid (AA) and docosahexaenoic acid (DHA) in TBE, an increase in DHA in co-infection and in free DHA in TBE with an increase in the level of lipid peroxidation products. The enhanced activity of enzymes metabolizing phospholipids and free PUFAs increased the level of endocannabinoids and eicosanoids, while decreased 15-PGJ2 and PGE2 was accompanied by activation of granulocyte receptors before pharmacotherapy and only tending to normalize after treatment. CONCLUSION: Since classical pharmacotherapy does not prevent disorders of phospholipid metabolism, the need to support treatment with antioxidants may be suggested.

Clinical characteristics and factors affecting disease severity in hospitalized tick-borne encephalitis patients in Norway from 2018 to 2022.

PURPOSE: To describe the clinical characteristics and factors associated with disease severity in a Norwegian cohort of hospitalized patients with tick-borne encephalitis (TBE). METHODS: This observational multicenter study included hospitalized patients with TBE in the endemic area in the southeastern region of Norway from 2018 to 2022. Clinical signs and findings from laboratory tests, EEG, CT and MRI scans were recorded. Patient characteristics were compared among those with mild, moderate, and severe TBE, and factors associated with disease severity were identified. RESULTS: Nearly all eligible patients were included in the final cohort (153/189 participants, 81%). The median age was 56 years, 63% were men, and 7% were vaccinated against TBE; no participants were fully vaccinated. TBE presented as mild (meningeal) disease in 31% of patients and as moderate or severe (encephalitic) disease in 54% and 14% of patients, respectively. We found that 46% of the patients had a monophasic course, 64% had hyponatremia, and 7% presented with central nervous system (CNS) symptoms without pleocytosis in cerebrospinal fluid (CSF). Dysesthesia, a symptom previously not described, was reported in 10% of the patients. Most objective findings were related to the CNS. Preexisting comorbidities, CRP and CSF protein levels were predictors of more severe disease. CONCLUSION: This novel presentation of a large Norwegian cohort supports TBE as a serious disease in the southeastern region of Norway. The majority of hospitalized patients presented with encephalitis, and fewer presented with meningitis. Comorbidities, CRP and CSF protein levels were associated with more severe disease. TRIAL REGISTRATION: Prosjekt #2,296,959 - The Norwegian Tick-borne Encephalitis Study - NOTES. Acute phase characteristics and long-term outcomes. - Cristin.

Esophagogastric Junction Outflow Obstruction (EGJOO): A Manometric Phenomenon or Clinically Impactful Problem.

PURPOSE OF REVIEW: Esophagogastric junction outflow obstruction (EGJOO), defined manometrically by impaired esophagogastric junction relaxation (EGJ) with preserved peristalsis, can be artifactual, due to secondary etiologies (mechanical, medication-induced), or a true motility disorder. The purpose of this review is to go over the evolving approach to diagnosing and treating clinically relevant EGJOO. RECENT FINDINGS: Timed barium esophagram (TBE) and the functional lumen imaging probe (FLIP) are useful to identify clinically relevant EGJOO that merits lower esophageal sphincter (LES) directed therapies. There are no randomized controlled trials evaluating EJGOO treatment. Uncontrolled trials show effectiveness for pneumatic dilation and peroral endoscopic myotomy to treat confirmed EGJOO; Botox and Heller myotomy may also be considered but data for confirmed EGJOO is more limited. Diagnosis of clinically relevant idiopathic EGJOO requires symptoms, exclusion of mechanical and medication-related etiologies, and confirmation of EGJ obstruction by TBE or FLIP. Botox LES injection has limited durability, it can be used in patients who are not candidates for other treatments. PD and POEM are effective in confirmed EGJOO, Heller myotomy may also be considered but data for confirmed EGJOO is limited. Randomized controlled trials are needed to clarify optimal management of EGJOO.

The long-term efficacy of tick-borne encephalitis vaccines available in Europe - a systematic review.

BACKGROUND: Despite the availability of vaccination, TBE (tick-borne encephalitis) remains a global public health problem. Therefore, the aim of our study was to assess the long-term efficacy of vaccinations against tick-borne encephalitis using vaccines available on the European market. METHODS: The analysis was conducted on the results of a systematic review conducted in accordance with the Cochrane Handbook for Systematic Reviews of Interventions. The search was performed in three databases, namely Medline (via PubMed), EMBASE (via Ovid), and the Cochrane Library database. The authors followed the PRISMA method and the selection of the articles was performed with two independent researchers. RESULTS: From a total of 199 citations, 9 studies were included in this review. According to the primary studies identified in the search, the efficacy of available anti-TBE vaccines ranges from 90.1% to 98.9%; however, in individuals above the age of 60, the protection wanes as early as one year after vaccination. Administration of a booster dose 3 years after completion of the basic vaccination schedule significantly extended the period of protection against TBE. CONCLUSIONS: Anti-TBE vaccines available in Europe have a high level of efficacy. However, the level of protection against TBE is decreasing after vaccination. Therefore, in addition to the conventional schedule, booster vaccines should be administered every 5 years in individuals before the age of 60 and more frequently, e.g. every 3 years, in individuals aged 60 and beyond.

Tick-borne encephalitis virus IgG antibody surveillance: vaccination- and infection-induced seroprevalences, south-western Germany, 2021.

BackgroundThe exact epidemiology of tick-borne encephalitis virus (TBEV) infections is unknown because many TBEV infections have an influenza-like or asymptomatic course. Surveillance data are based on patients with any (predominantly neurological) symptoms that prompted diagnostic testing. Infection- and vaccine-induced antibodies against TBEV can be distinguished using an NS1 IgG ELISA.AimIn a seroprevalence study we aimed to investigate TBEV antibody prevalence, incidences, manifestation indices and potential protection rates in a highly endemic district in south-western Germany.MethodsWe analysed 2,220 samples from healthy blood donors collected between May and September 2021. The reported number of TBEV infections was provided on a sub-district level by the local public health authorities. Blood samples were first screened using a TBEV IgG ELISA. In a second step, all positive samples were further analysed with a recently established NS1 IgG ELISA. The presence of specific antibodies against TBEV (excluding cross-reacting antibodies against other flaviviruses) was confirmed by testing screening-positive samples with a microneutralisation assay.ResultsOf 2,220 included samples, 1,257 (57%) tested positive by TBEV IgG ELISA and 125 tested positive for infection-induced TBEV NS1 antibodies, resulting in a TBEV NS1 IgG seroprevalence at 5.6% in our population. The yearly incidence based on the NS1 ELISA findings resulted in 283 cases per 100,000 inhabitants.ConclusionUsing the TBEV NS1 IgG assay, we confirmed a manifestation index of ca 2% and a high incidence of predominantly silent TBEV infections (> 250/100,000/year), which exceeds the incidence of notified cases (4.7/100,000/year) considerably.

Tick-borne encephalitis epidemiology and surveillance in Poland, and comparison with selected European countries before and during the COVID-19 pandemic, 2008 to 2020.

BackgroundTick-borne encephalitis (TBE) is the most common viral central nervous system (CNS) infection in Poland. Previous research suggests that its incidence was underestimated in the pre-pandemic period. The COVID-19 pandemic caused a considerable burden on surveillance systems, which could further impact reporting.AimWe aimed to assess the completeness of reporting of TBE in the years 2008 to 2020 and explore the potential impact of the COVID-19 pandemic on reporting to the epidemiological surveillance system, compared with hospitalisations for TBEV and other viral neuro-infections.MethodsWe compared the Polish epidemiology of TBE and other viral infections of the CNS from national surveillance reports with data on hospitalisations from 2008 to 2020 and data from selected European countries.ResultsBetween 2008 and 2020, 3,016 TBE cases were reported to surveillance compared with 3,620 hospitalisations. There was an increasing trend in hospitalisations, while surveillance data demonstrated the opposite, with the largest discrepancy observed in the first pandemic year (354 hospitalisations vs 159 cases reported to surveillance). Serological testing for TBE was used more in the known endemic region of north-eastern Poland and less in non-endemic areas. Other European countries reported higher TBE case numbers and an increase during the COVID-19 pandemic, whereas Poland observed an opposite trend.ConclusionThe sensitivity of TBE surveillance in Poland requires improvement. There are considerable regional differences. Regions that test for TBE intensively report most cases. Policymakers should be made aware of the value of quality epidemiological data for planning prophylactic measures in risk areas.

The thick-borne encephalitis caused by alimentary transmission - case series report.

Tick-borne encephalitis (TBE) is a central nervous system zoonotic disease transmitted by ticks. Tick-borne encephalitis virus (TBEV) is one of the main causes of lymphocytic meningitis in the areas of its endemic occurrence. A mode of transmission of TBEV which is rarely observed in clinical practice is an alimentary transmission through consumption of unpasteurised dairy products from infected animals. The following article contains detailed description of the clinical course of TBE among five family members, for whom the occurrence of TBE was temporarily associated with the consumption of unpasteurised goat's milk from the same source. The epidemiological outbreak presented in this article is the fifth ever described case of the milk-borne TBE in Poland. More so, the clinical course of the disease has shown differences from the typical course characterised so far in the literature. Clinical cases of TBE described in this study were similar to infections caused by tick bites in humans. The following article discusses available methods of preventing TBE, with emphasis on alimentary transmission of TBEV, since possibility of serious detrimental long-term neurological complications resulting from TBE was stressed in prior literature.

Deaths from Tick-Borne Encephalitis, Sweden.

We assessed standardized mortality ratio in tick-borne encephalitis (TBE) in Sweden, 2004-2017. Standardized mortality ratio for TBE was 3.96 (95% CI 2.55-5.90); no cases in patients <40 years of age were fatal. These results underscore the need for further vaccination efforts in populations at risk for TBE.

Clinical and Laboratory Characteristics and Outcome of Illness Caused by Tick-Borne Encephalitis Virus without Central Nervous System Involvement.

Information on febrile illness caused by tick-borne encephalitis virus (TBEV) without central nervous system involvement is limited. We characterized 98 patients who had TBEV RNA in their blood but no central nervous system involvement at the time of evaluation. Median duration of illness was 7 days; 37 (38%) patients were hospitalized. The most frequent findings were malaise or fatigue (98%), fever (97%), headache (86%), and myalgias (54%); common laboratory findings were leukopenia (88%), thrombocytopenia (59%), and abnormal liver test results (63%). During the illness, blood leukocyte counts tended to improve, whereas thrombocytopenia and liver enzymes tended to deteriorate. At the time of positive PCR findings, 0/98 patients had serum IgG TBEV and 7 serum IgM TBEV; all patients later seroconverted. Viral RNA load was higher in patients with more severe illness but did not differ substantially in relation to several other factors. Illness progressed to tick-borne encephalitis in 84% of patients within 18 days after defervescence.

Tick-Borne Encephalitis Virus RNA Found in Frozen Goat's Milk in a Family Outbreak.

Tick-borne encephalitis (TBE) is one of the commonest arthropod-borne viral diseases in Middle-East Europe and North Asia. The main reservoir of the virus is comprised of small rodents and domestic mammals with the common tick (Ixodes) being the usual vector. The clinical spectrum of TBE ranges from mild meningitis to severe meningoencephalomyelitis. This disease can lead to severe sequelae and has a mortality up to 2% in Europe. Even though the majority of cases are transmitted through bites of infected ticks, infections through ingestion of contaminated milk and dairy products from farms in endemic areas have been reported. We report a family outbreak of a febrile disease, initially suggestive of human-to-human infection, during the early summertime in Austria. Tick-borne encephalitis was diagnosed following consumption of unpasteurised goat's milk and the virus was subsequently detected in frozen milk samples. Although this is a rare manifestation of TBE, this case series shows that TBE should be included in the differential diagnosis of an outbreak of febrile disease, and a careful clinical history with reference to unpasteurized dairy products is crucial in order to prevent further disease spread. The best preventive measure is active immunisation of people living in, or travelling to, endemic areas.

The regional decline and rise of tick-borne encephalitis incidence do not correlate with Lyme borreliosis, Austria, 2005 to 2018.

BackgroundTick-borne encephalitis (TBE) virus is a human pathogen that is expanding its endemic zones in Europe, emerging in previously unaffected regions. In Austria, increasing incidence in alpine regions in the west has been countered by a decline in traditional endemic areas to the east of the country.AimTo shed light on the cause of this disparity, we compared the temporal changes of human TBE incidences in all federal provinces of Austria with those of Lyme borreliosis (LB), which has the same tick vector and rodent reservoir.MethodsThis comparative analysis was based on the surveillance of hospitalised TBE cases by the National Reference Center for TBE and on the analysis of hospitalised LB cases from hospital discharge records across all of Austria from 2005 to 2018.ResultsThe incidences of the two diseases and their annual fluctuations were not geographically concordant. Neither the decline in TBE in the eastern lowlands nor the increase in western alpine regions is paralleled by similar changes in the incidence of LB.ConclusionThe discrepancy between changes in incidence of TBE and LB support the contributions of virus-specific factors beyond the mere availability of tick vectors and/or human outdoor activity, which are a prerequisite for the transmission of both diseases. A better understanding of parameters controlling human pathogenicity and the maintenance of TBE virus in its natural vector-host cycle will generate further insights into the focal nature of TBE and can potentially improve forecasts of TBE risk on smaller regional scales.

Tick-borne Encephalitis Vaccine Failures: A 10-year Retrospective Study Supporting the Rationale for Adding an Extra Priming Dose in Individuals Starting at Age 50 Years.

BACKGROUND: Southern Sweden is endemic for tick-borne encephalitis (TBE), with Stockholm County as one of the high-risk areas. Our aim in this study was to describe cases of vaccine failures and to optimize future vaccination recommendations. METHODS: Patients with TBE were identified in the notification database at the Department of Communicable Disease Control and Prevention in Stockholm County during 2006-2015. Vaccine failure was defined as TBE despite adherence to the recommended vaccination schedule with at least 2 doses. Clinical data were extracted from medical records. RESULTS: A total of 1004 TBE cases were identified, 53 (5%) were defined as vaccine failures. In this latter group, the median age was 62 years (6-83). Forty-three (81%) patients were aged >50 years and 2 were children. Approximately half of the patients had comorbidities, with diseases affecting the immune system accounting for 26% of all cases. Vaccine failures following the third or fourth vaccine dose accounted for 36 (68%) of the patients. Severe and moderate TBE disease affected 81% of the cases. CONCLUSIONS: To our knowledge, this is the largest documented cohort of TBE vaccine failures. Vaccine failure after 5 TBE vaccine doses is rare. Our data provide rationale for adding an extra priming dose to those aged ≥50 years.

Comparison of tick-borne encephalitis between children and adults-analysis of 669 patients.

The aim of our study was to compare the course of TBE in children and adults. A retrospective analysis of the medical records of 669 patients was performed. The patients were categorized into 2 groups: Group I with 68 children and group II with 601 adults. TBE symptoms in children were milder compared with adults, with meningitis in 97% of cases. In adults, meningoencephalitis and meningoencephalomyelitis made up 49.26% of cases. Nausea and vomiting are more frequent in children, while neurological manifestations are more frequent in adults. There were no differences in CSF pleocytosis at the onset of disease in both groups, while CSF protein concentration was higher in adults. Children treated with corticosteroids over 7 days had higher checkup pleocytosis than pleocytosis at the onset of disease compared with adults. Corticosteroid use prolongs the disease duration but does not influence the development of TBE sequelae. Children had more favourable outcomes than adult patients.

Analysis of CCL-4, CCL-17, CCL-20 and IL-8 concentrations in the serum of patients with tick-borne encephalitis and anaplasmosis.

PURPOSE: Tick-borne co-infections are a serious epidemiological and clinical problem. Only a few studies aimed to investigate the effect of tick-borne encephalitis (TBE) and human granulocytic anaplasmosis (HGA) co-infection in the course of the inflammatory process and the participation of chemokines in the pathomechanism of these diseases. The aim of the study was to evaluate CCL-4, CCL-17, CCL-20, and IL-8 serum concentrations in patients with HGA, TBE and HGA + TBE co-infection. METHODS: Eighty-seven patients with HGA (n = 20), TBE (n = 49) and HGA + TBE (n = 18) were included to the study. The control group (CG) consisted of 20 healthy people. Concentrations of cytokines were measured in serum using commercial ELISA assays. In patients with TBE and HGA + TBE inflammatory markers were assessed during the acute and convalescent period. The results were analyzed using non-parametric tests with p < 0.05 considered as significant. RESULTS: Before treatment, significantly higher concentrations of IL-8, CCL-4 and CCL-20 were observed in HGA patients. CCL-4 and CCL-20 concentrations were significantly higher in TBE patients compared to CG. Concentrations of IL-8, CCL-4, and CCL-20 were significantly higher in HGA + TBE than in CG. After treatment, a significant reduction of IL-8, CCL-4, and CCL-20 concentrations in TBE patients and IL-8 in HGA + TBE co-infection was observed. CCL-4 concentration was higher in HGA + TBE co-infection in comparison to patients with TBE after treatment. CONCLUSIONS: Our study confirms that concentrations of IL-8, CCL-4, and CCL-20 are increased in the course of HGA and TBE. Their concentrations in serum may be used to monitor the course of TBE and HGA, as well as possibly detect co-infections with the diseases.

Molecular and Genetic Bases of Inhibition of Tick-Borne Encephalitis Virus Replication by Eprosartan and Ribavirin.

The antiviral activity of eprosartan (compound selected in silico) towards highly and low-virulent strains of tick-borne encephalitis virus was compared in vitro with activity of ribavirin. Study of the cytopathogenic activity of the virus on SPEV cells by ELISA, IFAT, and PCR showed similar results: both substances (eprosartan and ribavirin) promoted elimination of tick-borne encephalitis virus. Ribavirin exhibited intracellular inhibition towards both strains: the selectivity index for highly virulent Dal'negorsk strain was 160, for low-virulent Primorye-437 strain - 113. Eprosartan inhibited intracellular replication of Dal'negorsk strain (13.7) and less so that of Primorye-437 strain (2.9). The efficiency of virtual screening of the ligand (eprosartan) was demonstrated for highly virulent, but not low virulent tick-borne encephalitis strain.

Tick-borne encephalitis - a review of current epidemiology, clinical symptoms, management and prevention.

Tick-borne encephalitis virus (TBEV), which causes central nervous system infections, is a major health problem in Europe and Asia. This virus is transmitted mainly via the bite of a tick. However, an infection may also occur as a result of consuming raw milk. In 2018, a total of 3 092 cases of tick-borne encephalitis (TBE) were reported in EU countries. In recent years, TBE has emerged in previously unaffected regions; thus, new endemic areas have been identified. Most cases of TBE occur in spring and autumn, which correlates with increased tick activity. TBE is found in all age groups, including infants. The clinical presentation of TBE varies, but the severity of the infection and risk of complications increase with age. Post-encephalitic syndrome, which affects up to 50% of infected individuals, significantly reduces quality of life. Currently, there is no effective treatment for TBE, and supportive management is used in the acute phase of the disease. Therefore, anti-TBE immunization and the avoidance of tick bites are of key importance in preventing this infection.

Tick-Borne Encephalitis in Auvergne-Rhône-Alpes Region, France, 2017-2018.

Three autochthonous cases of tick-borne encephalitis (TBE) acquired in rural areas of France where Lyme borreliosis, but not TBE, is endemic highlight the emergence of TBE in new areas. For patients with neurologic involvement who have been in regions where Ixodes ticks circulate, clinicians should test for TBE virus and other tickborne viruses.

Intrathecal complement activation by the classical pathway in tick-borne encephalitis.

Tick-borne encephalitis (TBE) is one of the most prevalent viral central nervous system (CNS) infections in Eurasia and neurological sequelae are common. The immune responses are considered crucial for the pathogenesis. The aim of this study was to explore the activation of the complement system in TBE. The complement system is a part of the innate immune response in the CNS, which previously has been reported to be activated in other flavivirus infections. We analyzed complement factors in 44 paired cerebrospinal fluid (CSF) and serum samples from 20 cases of TBE in the acute and later stages, as well as in serum and CSF from 32 healthy controls. The concentrations of complement factors C1q, C3a, C3b, and C5a were determined with commercially available ELISA kits. Clinical data to categorize the severity of disease and outcome was retrieved from the medical records of the TBE patients. We found significantly higher concentrations of all of the analyzed complement factors in the CSF from TBE patients compared to the healthy controls. In particular, the marked increment of C1q concentrations in the CSF (p < 0,001 as compared to controls) indicated an intrathecal activation by the classical pathway. There was no correlation between complement factor concentrations in the CSF and severity of the disease in the acute phase or with sequelae at 6 months follow-up. We have found an intrathecal complement activation in TBE, and the marked increase of complement factor C1q indicated an activation by the classical pathway.