Tick-borne encephalitis ( TBE)

Topics with information and discussion about published studies related to Lyme disease and other tick-borne diseases.
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Yvonne
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Re: Tick-borne encephalitis ( TBE)

Post by Yvonne » Mon 21 Jun 2010 10:19

https://www.thieme-connect.com/ejournal ... 004-819478

Tick-borne encephalitis (TBE) in a 6 week old infant
Objective: TBE in a 6-week-old infant is reported with respect to possible vaccination strategies.


Case report: A 6-week-old girl developed fever, irritability, meningeal signs with bulging fontanelle and a partial, secondary-generalized seizure. CSF yielded pleocytosis (172 lymphocytes, 81 mono-cytes/ul) and elevated protein (0,83g/l), cranial MRI showed encephalitic signs in both frontal and parietal lobes. Because of a tick bite in an endemic area 10 days before admission, ELISA-IgG and IgM to TBE-virus were sought and found in serum, whereas Borrelia burgdorferi serology, Herpes-simplex virus PCR and bacterial CSF-culture were negative. Phenobarbitone was administered because of repetitive seizures, while the EEG showed series of sharp waves in the right parieto-temporal region. She consecutively became seizure free. At first follow-up after 6 weeks she demonstrated pathologic neurological signs with increased muscular tone, hyperreflexia, fidgety movements, and EEG showed slow waves in the right parieto-temporal region.


Conclusion: This is the youngest reported patient with TBE. The outcome of TBE in childhood is generally good. Because several cases with severe forms were reported in the recently, active immunization in endemic areas for children >6 years of age may be warranted. Even with an extended vaccination policy for younger children (Austria: in selected children ≥6 months) TBE in our infant could not have been prevented by immunization. Because of the here reported case and the increasing incidence of TBE in recent years, probably due to increased “outdoor-activity“, avoiding exposure to tick-bites is also an important means of prevention of TBE.
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Yvonne
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Re: Tick-borne encephalitis ( TBE)

Post by Yvonne » Fri 9 Jul 2010 16:06

Zoonoses Public Health. 2010 Jun 30. [Epub ahead of print]

Confirmed Exposure to Tick-Borne Encephalitis Virus and Probable Human Cases of Tick-Borne Encephalitis in Central/Northern Anatolia, Turkey.

Ergünay K, Saygan MB, Aydoğan S, Litzba N, Sener B, Lederer S, Niedrig M, Hasçelik G, Us D.

Department of Medical Microbiology, Faculty of Medicine, Hacettepe University, Ankara, Turkey.

Abstract
Summary Tick-borne encephalitis virus (TBEV) is the aetiological agent of tick-borne encephalitis (TBE), a potentially fatal central nervous system infection of humans. TBE is endemic in many areas of Europe and Asia; however, very scarce data on TBEV activity are available from Turkey. We aimed to identify TBEV exposure in healthy blood donors and the impact of TBEV in central nervous system infections in Central/Northern Anatolia. Two-thousand four hundred and fifty four sera, collected from blood donors at Ankara, Konya, Eskişehir and Zonguldak branches of the Turkish Red Crescent Middle Anatolia Regional Blood Center, were analysed for TBEV serosurveillance. Paired serum and cerebrospinal fluid samples from 108 patients with the diagnosis of aseptic meningitis/encephalitis of unknown aetiology were also evaluated to identify TBE and neuroborreliosis cases. Commercial enzyme-linked immunosorbent assays and indirect immunofluorescence tests were employed for antibody detection. Forty-seven donor samples (1.9%) were reactive for TBEV IgG. In 25 persons with IgG reactivity (53.1%), risk factors for tick-borne infections were revealed. One sample from Zonguldak province (1/198; 0.5%) in the Black Sea region of Turkey was confirmed to possess neutralizing antibodies via plaque reduction neutralization test. TBEV IgM was detected in 7.4% (8/108) of the patients. IgM was accompanied by IgG reactivity in two persons where, in one, recent history of a tick bite was also identified. Intrathecal antibody production for TBEV could not be demonstrated. No evidence for Borrelia infections could be found. Confirmed exposure to TBEV and/or an antigenically similar tick-borne flavivirus is documented for the first time in blood donors in Zonguldak in Northern Anatolia. Probable cases of TBE have also been identified from Central Anatolia. The epidemiology of TBEV activity in Turkey needs to be assessed and benefits of vaccination for general population, risk groups or travellers must be considered.

PMID: 20604912
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Yvonne
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Re: Tick-borne encephalitis ( TBE)

Post by Yvonne » Mon 12 Jul 2010 14:34

http://www.eurosurveillance.org/ViewArt ... leId=19606

Human activities predominate in determining changing incidence of tick-borne encephalitis in Europe

Eurosurveillance, Volume 15, Issue 27, 08 July 2010
Explanations for the dynamics of tick-borne disease systems usually focus on changes in the transmission potential in natural enzootic cycles. These are undoubtedly important, but recent analyses reveal that they may not be quantitatively the most significant side of the interaction between infected ticks and humans. Variation in human activities that may impact inadvertently but positively on both the enzootic cycles and the degree of human exposure to those cycles, provide more robust explanations for recent upsurges in tick-borne encephalitis in Europe. This can account for long-term increases in incidence that coincided with post-soviet political independence, for small-scales spatial variation in incidence within a country, and for short-scale fluctuations such as annual spikes in incidence. The patterns of relevant human activities, typically those related to the use of forest resources, are evidently driven and/or constrained by the cultural and socio-economic circumstances of each population, resulting in contrasting national epidemiological outcomes.



Discussion

Human activities of all sorts are commonly directed to a greater or lesser extent by geographically and temporally variable socio-economic constraints, with consequences for health (both non-communicable ill-health and directly transmitted infectious diseases) and reciprocal impacts of health on wealth, even within Europe [25-29]. For vector-borne zoonoses, human-induced environmental change (climatic, landscape, biotic) may affect the transmission potential of wildlife cycles, whereas human activities per se predominate in determining, and thereby potentially avoiding, contact with those cycles and so the risk of infection. This adds complexity and instability to the spatio-temporal dynamics of these disease systems. The analyses described here are based on correlational studies, which are by no means ideal for attributing causality to epidemiological patterns. They have, nevertheless, advanced our thinking significantly by identifying a range of new factors that need to be considered in future, more purpose-built, empirical studies. In the specific case of TBE in central and eastern Europe, many of the recent human-induced environmental changes originated in the socio-economic effects of political transition, and appear to have had an impact on the living conditions of all partners within this disease system - virus, ticks, wildlife and humans. Because of the biology of ticks as vectors, with their long generation time and slow pace of pathogen transmission due to the long interval between feeds, changes in transmission potential operate on a longer time scale than do changes in human exposure to infected ticks. The evidence presented in this review indicates that this latter effect can occur rapidly and thereafter may endure for variable periods, from a few months of extra recreation to many years of a new life-style. The fluidity with which people respond to new opportunities depends not only on current socio-economic conditions but also on their cultural traditions and expectations. The traditional exploitation of forests for food, apparently expanded either for export or for private enterprise in local markets or to enhance diets out of necessity or pleasure, has been quantified as a major risk factor for TBE [15,16]. Greater wealth, leisure and consequent potential for outdoor recreation brings similar risks. As soon as more than one causal factor is introduced, each operating with differential force and eliciting variable human responses, a spatially and/or temporally heterogeneous outcome is to be expected. Although many of these conclusions arise from detailed analyses of data from the Baltic States, because of the quality of data available there, entirely consistent patterns are seen where comparable information has been examined for other countries, notably Slovenia and the Czech Republic. This is striking, because these latter countries fall at opposite ends of both the geographical range of CEE countries and the spectrum of socio-economic impacts of the political reform of the early 1990s

Elsewhere in Europe, where socio-economic conditions have been more stable (pace the recent economic crises), the more gradual emergence of TBE may prove to be due more to enhanced enzootic cycles. In north-east Italy, the geographically defined appearance of TBE over the past two decades has been attributed to changes in forest structure, specifically a decreased ratio of coppice to high stand forest that has improved habitat suitability for rodents and deer [6]. As these authors point out, these changes in land and wildlife management practices are part of a shift from the pre-19th century concept of a forest as a wood-producer to the modern concept of a complex ecosystem highly connected with the territory where it is located, with cultural and aesthetic landscape values, and the functions of protecting hydrogeology, soil and biodiversity. Once again, human purposes, operating within a philosophy permitted by relative socio-economic wellbeing, are instrumental in driving TBE emergence.
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Yvonne
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Re: Tick-borne encephalitis ( TBE)

Post by Yvonne » Sat 14 Aug 2010 20:32

http://www.ncbi.nlm.nih.gov/pubmed/16334744

Hepatitis caused by tick-borne meningoencephalitis virus (TBEV)--a rare clinical manifestation outside the central nervous system involvement
Abstract

OBJECTIVE:
North part of Croatia, especially the Koprivnica-Krizevci County has been a well-known endemic area of tick-borne encephalitis (TBE) for more than 50 years. To date, this disease caused by tick-borne encephalitis virus (TBEV) has retained the leading position among inflammatory diseases of the central nervous system (CNS), with an average morbidity of 19 patients per year. In 88% of patients the infection manifested with signs of meningitis or meningoencephalitis with a biphasic course. TBE may take a more severe course with different neurologic dysfunction or even lethal outcome. There have been isolated reports on some rare clinical manifestations outside CNS involvement caused by TBEV, including transient hepatitis, pancreatitis, and myocarditis. These manifestations have been most frequently detected during the initial stage of disease but also as a complication, or as an individually separate clinical entity. The incidence rate of these manifestations is not known. Until now, such clinical manifestations outside CNS have not been reported in the county. It was the reason to present the characteristics of liver failure in our patients suffering from TBE. Purpose of Work: To determine the frequency of elevated aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels in patients with TBEV infection, to note the time from the detection to disappearance of elevated AST and to investigate and establish whether the degree of liver failure influences the course and outcome of TBE

PATIENTS AND METHODS:
The study was conducted from January 1991 until September 2004, and included patients with TBEV infection and elevated AST and ALT, examined at the Department of Infectious Diseases, Koprivnica General Hospital. Study patients were of all age groups and occupation. On their first examination detailed epidemiologic and patient history data were collected, with special reference to the history of alcohol abuse, disease of the liver or biliary tract, or any other apparent cause of liver failure. Clinical examination and laboratory tests were performed. Patients were classified into four groups as suffering from meningitis, meningoencephalitis, meningoencephalomyelitis, or abortive form of disease. The acute stage of meningoencephalitis was classified as mild, moderate or severe, depending on meningeal symptoms and severity of clinical signs of encephalitis, and presence of focal CNS signs. ELISA test was used to detect specific IgM and IgG antibodies. Serum samples were tested for other tick-borne diseases, including human monocyte and granulocyte ehrlichiosis. Oral consent was obtained from all patients enrolled in the study


RESULTS AND DISCUSSION:

During the study, recent infection with TBEV was proven in 261 patients. Liver function tests were done in 115 (44%) patients. Elevated AST and ALT activity was found in 25 (22%) patients, without bilirubin and alkaline phosphatase increase. All these were County residents, with a male sex predominance, aged 28-70 (median 41) years, and none had received TBE vaccination. Elevated AST and ALT activities were detected during the first stage of TBE in 16 (64%) and during the second stage of meningoencephalitis in 9 (36%) patients suffering from TBE. Elevated activity of AST was observed in 76% and of ALT in 96% of study patients. The most frequently observed elevated AST and ALT activity was two- or threefold the usual normal values. The time of the first detection of elevated AST and ALT activity could not be precisely determined, since all laboratory findings were performed during the first examination of patients. In the initial stage of disease, patients were mostly tested between 2-5 days from the onset of disease, and during the first week in the second stage of meningoencephalitis. Elevated AST and ALT activities were transient and normalized in 3-4 weeks. The importance of elevated AST and ALT activity for the course and prognosis of TBE was not verified in this study

CONCLUSION:
The first patients with hepatitis as one of the possible manifestation outside CNS involvement caused by TBEV are described. The prevalence and new concepts on this type of the disease were investigated in the study.
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