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During 1999–2012, 77% of the cases of tick-borne encephalitis (TBE) were recorded in two out of 16 Polish provinces. However, historical data, mostly from national serosurveys, suggest that the disease could be undetected in many areas. The aim of this study was to identify which routinely-measured meteorological, environmental, and socio-economic factors are associated to TBE human risk across Poland, with a particular focus on areas reporting few cases, but where serosurveys suggest higher incidence. We fitted a zero-inflated Poisson model using data on TBE incidence recorded in 108 NUTS-5 administrative units in high-risk areas over the period 1999–2012. Subsequently we applied the best fitting model to all Polish municipalities. Keeping the remaining variables constant, the predicted rate increased with the increase of air temperature over the previous 10–20 days, precipitation over the previous 20–30 days, in forestation, forest edge density, forest road density, and unemployment. The predicted rate decreased with increasing distance from forests. The map of predicted rates was consistent with the established risk areas. It predicted, however, high rates in provinces considered TBE-free. We recommend raising awareness among physicians working in the predicted high-risk areas and considering routine use of household animal surveys for risk mapping.

Background: Tick-borne encephalitis (TBE) is a viral infection with no available treatment. Due to its non-specific symptoms, TBE tends to be under-diagnosed and under-reported. We aimed to identify factors predicting TBE diagnosis to develop a diagnostic algorithm for use by physicians., Methods: We conducted a case-control study using data routinely collected in Poland during 2009-2010. We included patients admitted to hospitals, who were assigned an International Classification of Disease (ICD) code indicating aseptic meningo-encephalitis. Cases were confirmed by detection of specific IgG and IgM antibodies. Patients that tested negative for TBE were included as controls. We used logistic regression to determine associations and recursive partitioning to build a diagnostic algorithm based on 70% of the dataset, and validated the algorithm using the remaining 30%., Results: Of 774 patients, 273 (35%) were TBE-positive. Cerebrospinal fluid protein levels and presence of a tick bite were key decision points in the algorithm, while living in a TBE endemic area was not important. Application of the algorithm to the validation dataset yielded a sensitivity of 89% and specificity of 37%., Conclusions: TBE should be included in routine diagnostic protocols for all cases admitted to hospitals with meningitis or encephalitis. However, in resource-limited settings and in regions with unknown TBE endemicity status, our algorithm could indicate which cases should be tested for TBE.

We compared neighbouring regions of the Czech Republic (CZ) and Poland (PL) situated within 100 km of the country border, in order to compare surveillance systems performance in measuring the burden of tick-borne diseases in both countries. We used routine surveillance notifications from 1999-2008 on tick-borne encephalitis (TBE) and Lyme borreliosis (LB). We assessed the crude risk ratio (RR) across the country border, and its estimates adjusted for both population density and the expected epidemiological gradient across the region, using negative binomial regression. The crude RR between CZ and PL was 7.43 (95% Cl 6.20-8.90) for TBE, and 1.80 (1.76-1.83) for LB. The adjusted RR for TBE increased from 4.47 in 1999-2001 to 10.01 in 2005-2008, but for LB decreased from 9.30 to 2.51 during the respective periods. Those results reflect possible differences in surveillance systems performance between the two countries, as the administrative boundaries cannot constitute a barrier for zoonotic diseases and no biological processes alone can explain such large differences in disease occurrence.

Background: Tick-borne encephalitis (TBE) is found in limited endemic foci in Poland. Lack of diagnosis limits disease detection in non-endemic provinces., Methods: In 2009, we enhanced TBE surveillance to confirm the location of endemic foci and inform vaccination policy. In 105 hospitals located in 11/16 provinces, we identified suspected TBE cases through admission ICD-10 codes indicating aseptic meningo-encephalitis or from specimens tested for TBE. The National Reference Laboratory confirmed cases at no cost, by testing serum and/or cerebrospinal fluid using ELISA method. We calculated TBE reported rates as the number of confirmed TBE cases per 100,000 inhabitants. Adjusting to neighbouring districts, we classified districts as non-endemic (<0.1 cases per 100,000 inhabitants), low endemic (> = 0.1 to <1), moderately endemic (> = 1 to <5) and highly endemic (> = 5). We compared surveillance data obtained in 2009 with 2004-2008 baseline data., Results: Among 166,099 admissions, we identified 1,585 suspected TBE cases of which 256 were confirmed. Physicians reported more suspected cases among patients <40 years old (12 cases per 1,000 admissions) than among older patients (8 cases per 1,000 admissions). However, patients <40 years of age were confirmed less frequently (16%), than older patients (35%). Physicians reported more suspected cases in districts classed as endemic during 2004-2008 (12 cases per 1,000 admissions, 77% tested for TBE) than in districts classed as non-endemic (7 cases per 1,000 admissions, 59% tested). Of the 38 newly identified endemic districts, 31 were adjacent to 2004-2008 endemic districts and 7 were isolated., Conclusions: Enhanced surveillance detected 38 new endemic districts to be considered for TBE vaccination. However, lack of consistent testing in districts believed to be TBE-free remained an obstacle for mapping TBE risk. Although the disease affects mostly older adults and the elderly, more attention is given to the diagnosis of TBE in young patients. Solutions need to be identified to sustain sensitive, acceptable and affordable TBE surveillance in all districts of Poland. Also, higher attention should be given to the diagnosis of TBE in the elderly.

Tick-borne encephalitis virus (TBEV) is the most important tick-transmitted arbovirus causing human disease in Europe, but information on its endemic occurrence varies between countries because of differences in surveillance systems. Objective data are necessary to ascertain the disease risk for vaccination recommendations and other public health interventions. In two independent, separately planned projects, we used real-time RT-PCR to detect TBE virus in questing ticks. In Poland, 32 sampling sites were selected in 10 administrative districts located in regions where sporadic TBE cases were reported. In Germany, 18 sampling sites were selected in two districts located in a region with high TBE incidence. Altogether, >16,000 ticks were tested by real-time RT-PCR, with no sample testing positive for TBEV. A systematic search for published studies on TBEV prevalence in ticks in Poland and Germany also suggested that testing large numbers of collected ticks could not consistently assure virus detection in known endemic foci. Although assignment of results to administrative regions is essential for TBE risk mapping, this was possible in only 10 (investigating 22,417 ticks) of 15 published studies (>50,000 ticks) identified. We conclude that the collection and screening of ticks by real-time RT-PCR cannot be recommended for assessment of human TBE risk. Alternative methods of environmental TBEV monitoring should be considered, such as serological monitoring of rodents or other wildlife., (© 2012 Blackwell Verlag GmbH.)

Background: Tick-borne encephalitis (TBE) is endemic to Europe and medically highly significant. This study, focused on Poland, investigated individual risk factors for TBE symptomatic infection., Methods and Findings: In a nation-wide population-based case-control study, of the 351 TBE cases reported to local health departments in Poland in 2009, 178 were included in the analysis. For controls, of 2704 subjects (matched to cases by age, sex, district of residence) selected at random from the national population register, two were interviewed for each case and a total of 327 were suitable for the analysis. Questionnaires yielded information on potential exposure to ticks during the six weeks (maximum incubation period) preceding disease onset in each case. Independent associations between disease and socio-economic factors and occupational or recreational exposure were assessed by conditional logistic regression, stratified according to residence in known endemic and non-endemic areas. Adjusted population attributable fractions (PAF) were computed for significant variables. In endemic areas, highest TBE risk was associated with spending ≥10 hours/week in mixed forests and harvesting forest foods (adjusted odds ratio 19.19 [95% CI: 1.72-214.32]; PAF 0.127 [0.064-0.193]), being unemployed (11.51 [2.84-46.59]; 0.109 [0.046-0.174]), or employed as a forester (8.96 [1.58-50.77]; 0.053 [0.011-0.100]) or non-specialized worker (5.39 [2.21-13.16]; 0.202 [0.090-0.282]). Other activities (swimming, camping and travel to non-endemic regions) reduced risk. Outside TBE endemic areas, risk was greater for those who spent ≥10 hours/week on recreation in mixed forests (7.18 [1.90-27.08]; 0.191 [0.065-0.304]) and visited known TBE endemic areas (4.65 [0.59-36.50]; 0.058 [-0.007-0.144]), while travel to other non-endemic areas reduced risk., Conclusions: These socio-economic factors and associated human activities identified as risk factors for symptomatic TBE in Poland are consistent with results from previous correlational studies across eastern Europe, and allow public health interventions to be targeted at particularly vulnerable sections of the population.

In July-November 2009, 26 European Union (EU) Member States (MSs), Norway and Iceland, participated in a survey seeking information on national tick-borne encephalitis (TBE) vaccination recommendations. Information on TBE surveillance, methods used to ascertain endemic areas, vaccination recommendations, vaccine coverage and methods of monitoring of vaccine coverage were obtained. Sixteen countries (57%) reported presence of TBE endemic areas on their territory. Vaccination against TBE was recommended for the general population in 8 (28%) countries, for occupational risk groups - in 13 (46%) countries, and for tourists going abroad - in 22 (78%) countries. Although vaccination recommendations for country residents, and for tourists always referred to endemic areas, there was no uniform, standardized method used to define endemic areas. For this reason, clear recommendations for tourists need to be developed, and standardized surveillance directed to efficient assessment of TBE risk need to be implemented in European countries., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

A tick-borne encephalitis outbreak involving 25 patients of 154 exposed persons occurred in Hungary in August 2007. None of the patients had a history of tick-bite, however all of them drank unpasteurized raw goat milk from the same farm. The aim of this study was to identify the goats on the farm which could have spread the infection through their milk. Blood samples were taken from 75 goats on the farm and were examined by various serological methods, namely indirect immunofluorescent assay, hemagglutination inhibition, microneutralization and an ELISA adapted to testing material from goats, to determine antibody levels in the serum. The four methods have proved different levels of specificity. The least specific was the indirect immunofluorescent assay, which showed a low titre in all sera. Comparison of the results of the other three methods indicates that two sera were positive for anti-TBEV IgG and one for anti-TBEV IgM. The goat with the IgM positive serum sample could have been a source of the infected milk. It has been concluded that serological results for goats by the different methods should be compared before final diagnosis because the specificity of methods in use can differ significantly., (2009 Elsevier B.V. All rights reserved.)

In Poland, 3,361 cases of neuroinfections were reported in 2007, of which 1,078 had bacterial etiology, 1,717--viral aetiology, and 566--other or unknown origin. The etiological agent was determined in 611 (57%) cases of bacterial neuroinfections. Among them N. meningitidis was found in 224 cases, H. influenzae type B (Hib) in 35 cases and S. pneumoniae in 161 cases. An increasing trend in meningococcal infections incidence has been observed in 2007, and a substantial decrease ofHib incidence, related to increasing vaccination coverage. Viral neuroinfections incidence in 2007 increased compared to year 2006. Among confirmed cases, there were 233 cases oftick-borne encephalitis. Most of the cases were reported from endemic areas of north-eastern part of the country.

Currently an ecologic study assessing the relationship between tick-borne encephalitis (TBE) with diverse environmental and social factors at the lowest administrative level is developed for Poland. Because the disease is affecting only part of the country, the authors will try to identify factors which could explain this uneven geographic distribution of the disease. To increase precision of the analysis we will utilize the highest possible resolution of the analysis, for which routinely collected data are available. Part of the data at the commune level will be obtained from the Polish communicable disease surveillance system and the Central Statistical Office, and part will be obtained using GIS tools from maps prepared by diverse institutions. The outcome studied will be TBE cases assigned to commune of residence or to place of exposure. The explanatory variables will be: land use categories (percent of commune area and their border length), meteorological variables (temperatures, rainfall), socio-economic status of communes (income per capita, unemployment rate), and Lyme borreliosis incidence (as a complex indicator of tick activity and human to tick exposure).

In Poland, 3 693 cases of neuroinfections were reported in 2006, of which 989 had bacterial aetiology, 1 874--viral aetiology, and 512--other or unknown origin. The etiological agent was determined in 455 (46%) cases of bacterial neuroinfections. Among them Neisseria meningitidis was found in 148 cases, Haemophilus influenzae type B (Hib) in 39 cases and Streptococcus pneumoniae in 119 cases. An increasing trend in meningococcal infections incidence has been observed in 2006, and a substantial decrease of Hib incidence, related to increasing vaccination coverage. Viral neuroinfections incidence in 2006 increased compared to year 2005. Etiological factors of central nervous system aseptic infections were established only in minor proportion of cases--3% of meningitis and 20% of encephalitis. Among confirmed cases, there were 317 cases of tick-borne encephalitis and 31 cases of herpetic encephalitis. Tick borne encephalitis incidence increased in 2006 (0.83), compared to 2004 - 2005. Most of the cases were reported from endemic areas of north-eastern part of the country.

The paper summarizes state of art knowledge on tick-borne diseases epidemiology in Poland. The most prevalent diseases are Lyme borreliosis (LB) and tick-borne encephalitis (TBE). Although there is growing number of data published on anaplasmosis and babesiosis prevalence in ticks and humans, there is no national data on these diseases and their epidemiological features remain unclear. All tick-borne agents have a common vector tick--the sheep tick Ixodes ricinus. LB and TBE are mandatory reportable diseases. In 2005 case definitions were implemented in Poland to allow a better comparability of data within the country and with other European countries. LB is widespread in Poland. Studies of prevalence of infected ticks indicate that from 6 to 15% of I. ricinus ticks in different sites are infected with the spirochete. Data from seroepidemiologic studies and from routine surveillance (started in 1996) confirm that the disease is widespread in Poland, and its incidence is increasing. It has increased from 2.31 per 100,000 in 1999 to 11.55 in 2005. One reason of this increase is the improvement in diagnosis of the disease. There is a need to promote personal protection during outdoor activities and knowledge on LB symptoms, especially among populations at risk--forestry workers, farmers. TBE incidence is limited to two main foci--one in the Northeast of Poland bordering Baltic states endemic region, and the second on the South of Poland, neighbouring the Czech and Slovak republics. Seroepidemiologic data, supported by surveillance data, indicate that there are areas of particularly high TBEV activity. The mostly affected occupational groups are: unemployed, retired, students, and farmers. This is a reason to promote personal protection and prophylactic vaccination of both inhabitants of endemic regions and tourists visiting endemic regions.

The 7th meeting of the ISW TBE had the main topic "Tick-borne encephalitis in the Golden Agers". Data from 14 European countries were presented about incidence and clinical course of Tick borne encephalitis (TBE) in general and especially in the population over 50 years of age. With age immunity is impaired quantitatively and qualitatively, the reactions to vaccinations are generally slower, antibody titres reach lower values and decrease earlier. The incidence of the disease is increasing with age, also the clinical course is more severe, they suffer significantly more sequelae, need a longer rehabilitation and have a higher case fatality. Vaccination as the only efficient protection is needed in endemic areas, considering that mobility has increased very much. For the age group over 50 years regular booster vaccinations according to the recommended vaccination intervals or even shorter intervals are most important.

Central European tickborne encephalitis (TBE) is a viral disease of the central nervous system. Despite a surveillance system for TBE existing in Poland since 1970, there are no standardised case definitions and different diagnostic tests are used in various regions. The purpose of this study was to summarise four years of surveillance data using standardised case definitions. From 1999 to 2002, 607 cases of TBE were reported to Poland's national surveillance system: 386 (63.6%) were males, 331 (54.5%) lived in rural areas, and 186 (30.6%) were between 30 and 50 years old. Of 606 diagnosed cases, 453 (74.7%) had aseptic meningitis, 109 (18.0%) had meningoencephalitis, and 44 (7.3%) had meningoencephalomyelitis. Of the 607 reported cases, 602 (99.2%) could be classified: 153 (25.4%) as confirmed, 343 (57.0%) as probable, and 106 (17.6%) as possible cases. There was a significant difference in classified cases by gender: 28.6% of male cases were classified as confirmed, compared with 19.7% of female cases (chi2= 10.48, p=0.0053). There was a significant difference in case classification by clinical diagnosis: 32.4% of cases with meningoencephalitis were classified as confirmed cases, compared with 24.7% of cases with aseptic meningitis (chi2=11.79, p=0.019). There were also significant differences in the distribution by case definition group across geographical regions. For appropriate monitoring of TBE, a uniform and valid case definition should be used in European countries. With only 25% of reported cases meeting the definition for confirmed cases, there is a need for more complete follow-up and standardised testing of suspect cases.