The occurrence of Ixodes ricinus ticks and important tick-borne pathogens in areas with high tick-borne encephalitis prevalence in different altitudinal levels of the Czech Republic Part I. Ixodes ricinus ticks and tick-borne encephalitis virus.

STUDY OBJECTIVE: The aim of the three-year study (2011-2013) was to monitor population density of Ixodes ricinus ticks and its infection rate with the tick-borne encephalitis virus in areas with a high incidence of tick-borne encephalitis as reported in the previous decade 2001-2010. Such a comprehensive and long-term study based on existing epidemiolo-gical findings has not previously been conducted in Europe. MATERIAL AND METHODS: In the areas of the Ústí nad Labem Region, Olomouc Region, South Bohemian Region, and Highlands Region, 600 m2 plots were selected in the local optimal I. ricinus habitats where tick flagging was performed every year in the spring-summer and autumn seasons of the questing activity. In total, 18,721 I. ricinus ticks (1448 females, 1425 males, and 15,848 nymphs) were collected and investigated. RESULTS AND CONCLUSION: The results have shown that the differences in the infection rate of I. ricinus observed between regions are driven by variation in the density of the local I. ricinus populations which is influenced by the characteris-tics of the whole local biocenosis. The overall prevalence estimate of TBE virus in Ixodes ricinus ticks at the altitudes below 600 m a.s.l. was 0.096 % (95% CI 0.055-0.156) for nymphs, and 0.477 % (95% CI 0.272-0.773) for adults. The dynamics of the seasonal variation in I. ricinus populations, depending primarily on the climatic factors, are behind the interyear differences in the infection rate of ticks and, consequently, in the epidemiological situation of tick-borne encephalitis. The nymph to adult ratio was 5.5 on average but showed great interregional variability (from 10.3 in the Ústí nad Labem Region to 1.8 in the Highlands Region). It might be used in the future as one of the indicators of the composition of the local I. ricinus population and of the level of the circulation of tick-borne pathogens in zoonotic sphere and also for use in the health risk assessment in a given area. Despite the permanent expansion of ticks and tick-borne pathogens in higher altitudes the high risk limit for human infection with tick-borne encephalitis is 600 m a.s.l. in the Czech Republic.

Seroprevalence of hantavirus antibodies among chronic hemodialysis patients in the Czech Republic.

A total of 348 serum samples were collected from 301 hemodialysis patients with chronic renal failure of four healthcare settings in Western Bohemia. The sera were screened for the presence of hantavirus antibodies using ELISA kits (PROGEN Biotechnik GmbH) with Hantaan and Puumala antigens. Specific anti-Puumala antibodies were detected in five patients (1.7%). Although hantaviruses are known to cause primarily acute renal damage (interstitial nephritis) in Eurasia, chronic effects of hantavirus infection and the detection of specific antibodies in hemodialysis patients have also been reported. Nonetheless, the detection of seropositivity is not proof of an etiological link between hantaviruses and chronic renal failure. The hantavirus seropositivity rate in hemodialysis patients was not significantly higher than that in the general population. Our findings are consistent with the literature data and do not contradict the contribution of hantaviruses to the pathogenesis of chronic renal damage in the Czech Republic.

Prevalence of antibodies against hantaviruses among the adult population of the Czech Republic.

At least three hantavirus genospecies are circulating among wild rodents in Europe: Puumala, Dobrava and Tula, the two first being of clinical significance for humans as possible causative agents of haemorrhagic fever with renal syndrome. As many as 710 adult individuals randomly selected from 12 regions of the Czech Republic were screened for the presence of antibodies against hantaviruses. Commercial sets with Hantaan and Puumala antigens were used for this purpose. Five subjects showed IgG reactivity to Hantaan-like virus (Dobrava) and one subject tested positive for both IgG and IgM antibodies. Two other subjects showed IgM reactivity alone. This means that as many as seven (1.0%) subjects showed reactivity to Hantaan antigen. Eight subjects showed IgG reactivity to Puumala antigen, none of them being IgM positive. Two other subjects were IgM positive only. Altogether ten (1.4%) subjects were reactive to Puumala antigen. Three subjects showed reactivity to both of the antigens tested.

[Importance of regular screening for genital chlamydiosis in adolescents]. / Význam pravidelne opakovaného screeningu genitální chlamydiózy u dospívající mládeze.

OBJECTIVE: Determination of prevalence of genital chlamydiosis in similar group of adolescents as in that examined two years ago. Comparison of the results with the previous ones to confirm positive impact of a repeated screening on drop of prevalence of the infection. Another objective is to make the epidemiological data on genital chlamydiosis in the countries of the "Eastern Block" more accurate, and at the same time to assess the most suitable screening method. DESIGN: Prospective epidemiological study aimed at finding whether the repeated screening examinations of genital chlamydiosis in adolescents will result in decreased incidence of the infection. SETTING: Veterinary Research Institute, Department of Clinical Microbiology of the Faculty Hospital, Regional Hygienic Station, Department of Gynecology and Obstetrics, Medical Faculty, Masaryk University, Brno. METHODS: The groups under testing comprised male and female students of two secondary medical schools and one private grammar school older than 18 (n = 232, of which 33 were boys and 199 girls). Direct detection of C. trachomatis was carried out from the urinary sediment of the sample of morning urine using ligase reaction, polymerase chain reaction, ELISA and direct immunofluorescence. RESULTS: Identical positive result of C. trachomatis detection by four methods was obtained 4 times, i.e. 1.7%. The result of LCR and PCR were positive identically (4 times), ELISA and IF were, besides the above results, positive in other 1 resp. 5 cases. CONCLUSION: Screening examinations of genital chlamydiosis were performed in adolescents in the town of Brno. Morning samples of urine from 232 students of secondary schools were examined on C. trachomatis using the following methods: LCR, PCR, ELISA, and IF. The LCR and PCR were positive 4 times, ELISA 5 times, IF 9 times. Positive results by LCR and PCR were identical. ELISA and IF were positive in other cases. Noninvasive methods are suitable for screening of latent genital chlamydiosis and for estimation of its prevalence. The authors of the study recommend the ligase chain reaction (LCR) as a most suitable screening method.

[Detection of hantavirus antigen in rodents in the Czech Republic]. / Nálezy hantavirového antigenu u hlodavcu v Ceské republice.

The work is based on the hitherto implemented examinations of lungs of rodents from the territory of the Czech Republic for the presence of hantavirus antigen. For detection of a species specific antigen the ELISA set Hantagnost from the Poliomyelitis Institute in Moscow was used. A total of 1494 micromammalia of 15 species caught in 1991-2001 were examined. The hantavirus antigen was detected in the lungs of 101 individuals (6.8%) whereby representatives of the species Microtus arvalis predominated markedly: 97 positive from 687 examined (14.1%). Twice the hantavirus antigen was proved in Microtus subterraneus and once each in Apodemus sylvaticus and Clethrionomys glareolus. From hitherto assembled findings ensures that most probably genotype Tula was involved. The authors observed a direct correlation of positivity on the increase of volves and the season of their catching with maxima in the spring and autumn months. No correlation with the sex of the host was found.

[Noninvasive screening for genital chlamydiosis in adolescents in Brno]. / Neinvazivní screeningové vysetrení genitální chlamydiózy adolescentu mesta Brna.

OBJECTIVE: To run a screening for genital chlamydiosis in adolescents living in the town Brno as the first action of this type in the Czech Republic and to use the results of the screening for the elaboration of recommendations for running similar actions on the national scale. DESIGN: Prospective epidemiological study. SETTING: Veterinary Research Institute, Brno; Institute of Clinical Biochemistry, 1st Faculty of Medicine, Charles University and General Faculty Hospital, Prague; Section of Public Health, Municipal Authorities of Brno; Bioplus Ltd., Brno; Regional Hygienic Services, Brno; Faculty Hospital Brno; with technical assistance of teachers and students of two Medical Assistant Schools in Brno. METHODS: Students (337 females and 15 males) of two Medical Assistant Schools, older than 18 years, were used as probands within the study. Sediments of the first portions of urine collected from the individual probands were tested for the presence of Chlamydia trachomatis using the direct fluorescent test, ELISA, and the ligase chain reaction. RESULTS: Positive reactions in any of the three tests were found in 31 of the 352 probands (8.8%). Positive and doubtful reactions in the direct fluorescent antibody test were obtained in 11 (35.5%) and 3 (9.6%) of the 31 reactors, respectively. The corresponding values for ELISA were 9 (23.0%) and 8 (25.8%), respectively, and those for the ligase chain reaction 3 (16.6%) and 3 (16.6%), respectively. The overall prevalence of 8.8% is higher than the European mean. CONCLUSIONS: The first limited screening for genital Chlamydia infections in the Czech Republic was run in Brno. Urinary samples were collected from 337 females and 15 males aged approximately 18 years. The presence of Chlamydia trachomatis in the urinary sediment was demonstrated by the direct fluorescent test, ELISA, and the ligase chain reaction. The established prevalence of 8.8% exceeded the European mean (3.9%).

Recombination in Tula hantavirus evolution: analysis of genetic lineages from Slovakia.

To examine the evolution of Tula hantavirus (TUL), carried by the European common vole (Microtus arvalis and M. rossiaemeridionalis), we have analyzed genetic variants from Slovakia, the country where the virus is endemic. Phylogenetic analysis (PHYLIP) based on either partial (nucleotides [nt] 441 to 898) or complete N-protein-encoding sequences divided Slovakian TUL variants into two main lineages: (i) strains from eastern Slovakia, which clustered with Russian strains, and (ii) strains from western Slovakia situated closer to those from the Czech Republic. We found genetic diversity of 19% between the two groups and 4% within the western Slovakian TUL strains. Phylogenetic analysis of the 3' noncoding region (3'-NCR), however, placed the eastern Slovakian strains closer to those from western Slovakia and the Czech Republic, with a greater distance to the Russian strains, suggesting a recombinant nature of the S segment in the eastern Slovakian TUL lineage. A bootscan search of the S-segment sequences of TUL strains revealed at least two recombination points in the S sequences of eastern Slovakian TUL strains (nt 400 to 415 and around 1200) which agreed well with the pattern of amino acid substitutions in the N protein and deletions/insertions in the 3'-NCR of the S segment. These data suggest that homologous recombination events occurred in the evolution of hantaviruses.

[Occurrence of antibodies to chlamydial group antigens in the population of the Czech Republic]. / Výskyt protilátek proti skupinovému chlamydiovému antigenu v lidské populaci CR.

A set of 4,178 human blood sera was tested including 3,093 samples collected from blood donors, 624 randomly collected samples. 124 samples collected from persons possibly exposed to Chlamydia infection, and 337 samples from patients of various hospitals in the districts of Brno, Olomouc and Rumburk. All the sera were examined using the complement fixation microtest and the antigen of Chlamydia psittaci for CFR (Bioveta, Ivanovice na Hané, CzR). Moreover, a subset of samples collected from selected groups (n = 209) was tested by CFR using the genus-specific Ornithose-Antigen (Behring, Germany) (n = 209), another subset of 116 samples by indirect immunofluorescence using the biological Chlamydia trachomatis Spot IF (Bio Merieux) (n = 116), and a subset of 224 samples by ELISA for the demonstration of IgG, IgM and IgA class of antibodies using the kit rELISA Medac. Complement fixing antibodies assayed with the Chlamydia psittaci antigen (Bioveta), reached titres of 1.5, 1:10 and 1:20 in 15.5%, 5.29% and 0.48% of the randomly collected samples, respectively. The corresponding values for the tests carried out with the Ornithose-Antigen were 1:10 in 10.9%, 1:20 in 8.9%, 1:40 in 2.9% and 1:80 in 1.4%. ELISA yielded 52.7%, 26.85% and 17.59% positive results in the globulin classes IgG, IgA and IgM, respectively. Antibody titres from 1:20 and from 1:10, determined with the Bioveta antigen, were found in 2.36% and 9.47% within a representative group of blood donors. The corresponding values for the group of the hospitalized patients were 14.54% and 24.93%, respectively, and for the group of persons possibly exposed to Chlamydia infection 2.42% and 8.87% respectively. The indirect immunofluorescence test yielded positive, negative ad doubtful results in 47.41%, 27.59% and 25.0% persons of the latter group. This group showed also a higher percentage (37.07%) of positive results in ELISA in the class IgA than the randomly selected persons.

[Hemorrhagic fever with renal syndrome]. / Hemoragická horecka s renálním syndromem.

The authors describe the illness of a Czech soldier who while serving in the UNPROFOR forces in an area with the endemic occurrence of hantaviruses became infected with this agent and developed haemorrhagic fever with renal syndrome. The severe clinical course which called for seven haemodialyzation procedures led to the patient's recovery. The authors describe the course of the disease and epidemiological circumstances.

Isolation and characterization of Tula virus, a distinct serotype in the genus Hantavirus, family Bunyaviridae.

A Vero E6 cell culture isolate of Tula virus (TUL), a hantavirus first detected in European common voles (Microtus arvalis and M. rossiaemeridionalis) by RT-PCR was obtained after initial passaging of TUL-infected vole lung samples in laboratory-colonized M. arvalis. TUL was defined as a classical serotype by a cross-focus-reduction neutralization test (FRNT) and was also shown to be distinct from other hantaviruses by haemagglutination inhibition assay. The sequences of S, M and partial L genome segments of the isolate were determined: the S segment was 99.9% identical to the original rodent-derived sequence. Serological evidence for a previous TUL infection was obtained from the serum of a blood donor living near a TUL focus in Moravia, Czech Republic, showing at least a 16-fold higher FRNT titre to TUL as compared to Puumala or other hantaviruses.

[Detection of chlamydia in the intestines and lungs in pigeons and humans]. / Prukaz chlamydií ve streve a plicích holubu a lidí.

Attempts were made to detect Chlamydia sp. by direct immunofluorescence (IF) in intestinal and lung tissues collected from wild town pigeons, young reared pigeons, and human corpses. Chlamydia in any organ were detected in 86.6% of the 427 adult pigeons and 27.3% of 16 young pigeons. Positive IF results were in intestinal and lung samples, collected from 427 adult pigeons, in 34.3% and 40.05% of the birds, respectively. Human (n = 100) intestinal and lung tissues were positive in 22% and 20% of the corpses, respectively. Titres 1:20 and higher were demonstrated by CF in 53.86% of the 427 adult pigeons. The highest titre found was 1:5 120.

[An imported case of hemorrhagic fever with renal syndrome]. / Importovaný prípad hemoragické horecky s renálním syndromem.

The authors present a case of haemorrhagic fever with renal syndrome imported from a region of endemic occurrence of hantaviruses in the Balkans. The patient contracted the infection in connection with service in the Czech UNPROFOR unit. The affection manifested itself as renal insufficiency and required a total of seven haemodialyses for complete recovery. The epidemiological context and clinical course of the disease are described in detail.

Genetic variation in Tula hantaviruses: sequence analysis of the S and M segments of strains from Central Europe.

Hantavirus carried by the European common vole Microtus arvalis from Moravia (Czech Republic) was analyzed by RT-PCR-sequencing and by reactivity with a panel of monoclonal antibodies (MAbs). Sequencing of the full-length S segment and the proximal part of the M segment showed that the virus belonged to genotype Tula (TUL) we discovered earlier in Microtus arvalis from Central Russia. This finding supported the concept of host dependence of hantaviruses. Phylogenetic analyses suggested a similar evolutionary history for S and M genes of TUL strains; thus far there is no evidence for reassortment in TUL. Geographic clustering of TUL genetic variants was observed and different levels of the genetic variability were revealed resembling those estimated for another hantavirus, Puumala (PUU). Comparison of the deduced N protein sequence from Russia and from Moravia showed that genetic drift in TUL occurred not only by accumulation of point mutations but also by the deletion of a nucleotide triplet. It encoded Ser252 which was located within a highly variable hydrophilic part of the N protein carrying B-cell epitopes and presumably forming a loop. Analysis of naturally expressed TUL N-antigen derived from lung tissue of infected voles with MAbs indicated antigenic heterogeneity among TUL strains.

[Prevalence of hantavirus infection in small mammals in the South Moravian Region]. / Prevalence nákaz drobných savcu hantaviry v Jihomoravském kraji.

In 1987 to 1990 in the South Moravian region 1094 lungs of small terrestrial mammals were examined for hantavirus antigen and sera of 525 rodents and 93 hares for antibodies against these viruses. In the majority the materials were not from the same individual. Lungs were examined by the ELISA method, antibodies were assessed by the indirect immunofluorescence reaction. An antigen resembling the western subtype (Puumala) was found in 65 animals (5.9%) of two rodent species (Microtus arvalis--63 times and Apodemus flavicollis--twice) in 20 localities. Antibodies against this subtype were detected in 25 examined individuals (4.0%) of four species (Microtus arvalis, Apodemus flavicollis, Pitymys subterraneus and Lepus europaeus) from eight localities. A marked predominance of positive findings was obtained from Microtus arvalis which under conditions of the South Moravian region can be considered the main host of hantaviruses of the western subtype. Only in one specimen of Clethrionomys glareolus from Hrbov antibodies against the eastern subtype were detected (Hantaan). Hantaviruses form in Southern Moravia natural foci of the avector type, in particular in perennial fodder crops, most frequently with a mesophil character of the site. The foci were found most frequently at sites of assumed borderlines of natural meadow forests of the Alno-Padion type and woods of the Carpinion betuli, Quercion robori-petreae and Fagion silvaticae type.

[Antibodies against Hantaviruses in game and domestic oxen in the Czech Republic]. / Protilátky proti hantavirum u lovné zvere a turu domácího v Ceské republice.

Using the test of indirect immunofluorescence, the authors examined sera of animals for antibodies against the strain CG 18-20 of Hantavirus (identical with strain Puumala) and against the Hantaan strain. As a control and supplement of the examination the authors used cells containing the TBE virus, strain Hypr. In a group of 260 hares (Lepus europaeus) in 3.5% antibodies were present against Hantavirus CG 18-20. Of 41 deer (Capreolus capreolus) they were present in 14.1%. Of 11 fallow-deers none had antibodies against hantaviruses. Among 145 specimens of Bos taurus antibodies were present in two incl. one against the strain Hantaan. The findings are discussed in relation to previous research of natural foci of hantavirus infections and infections with the TBE virus in Bohemia and Moravia. The paper reveals hitherto unknown localities of foci and hitherto not studied participants of the circulation of hantaviruses.

Isolation of Tahyna virus from biting midges (Diptera, Ceratopogonidae) in Czecho-Slovakia.

A total of 14,250 haematophagous biting midges (genus Culicoides, Diptera: Ceratopogonidae) were collected in June 1986 in the mountains Ceskomoravská vysocina (about 600 m above sea level); from these 2 strains of Tahyna virus (serogroup California, Bunyaviridae) were isolated. To our knowledge this is the first isolation of a California serogroup virus from the species of family Ceratopogonidae as well as the first report of arbovirus isolation from biting midges in Europe.

Hantaviruses in small wild living mammals in Czechoslovakia. Results of a 1983-1989 study.

During a 7- year period were hunted small wild living mammals and examined by ELISA and RIA techniques for the presence of hantavirus antigen and/or antibodies by MFA. In total 3,050 animals of 16 species caught in 9 out of 10 regions of Czechoslovakia, were examined. The proportion of positive animals was 4.4%. To the positive ones with the serotype 2 (Western type) belonged the following: M. arvalis, C. glareolus, P. subterraneus, A. sylvaticus, A. flavicollis. To the Eastern serotype: A. agrarius in eastern Slovakia, A. flavicollis in North of Bohemia and A. sylvaticus in South of Moravia. The repeatedly examined localities were found to be either repeatedly positive or repeatedly negative. The antigen titres in the lungs of M. arvalis were constant irrespective of sex and season of capture. They were, however, much higher in young animals, whereas the proportion of positivities was higher in adults ones. The titres of antigen in the lungs of C. glareolus never exceeded those of M. arvalis.