Emergence of tick-borne encephalitis in new endemic areas in Austria: 42 years of surveillance.

Human infections with tick-borne encephalitis (TBE)virus are a public health concern in certain regions of Europe, central and eastern Asia. Expansions of endemic areas and increased incidences have been associated with different factors including ecological changes supporting tick reproduction, socioeconomic changes increasing human outdoor activities and climatic changes favouring virus circulation in natural foci. Austria is among the most strongly affected countries in Central Europe, but the annual number of cases has strongly declined due to vaccination. Here,we have analysed changes of the incidence of TBE in the unvaccinated population of all federal states of Austria over a period of 42 years. The overall incidence in Austria has remained constant, but new strongly affected endemic regions have emerged in alpine valleys in the west of Austria. In parallel, the incidence in low-land regions in the north-east of the country is decreasing. There is no evidence for a shift to higher altitudes of infection sites in the traditional TBE zones,but the average altitudes of some newly established endemic areas in the west are significantly higher. Our analyses underscore the focal nature of TBE endemic areas and the potential of TBE virus to emerge in previously unaffected regions.

In vitro-synthesized infectious RNA as an attenuated live vaccine in a flavivirus model.

Live virus vaccines have in many cases proven to be an extremely effective tool for the prevention of viral diseases. However, the production of conventional live vaccines in eukaryotic cell cultures has many disadvantages, including the potential for contamination with adventitious agents and genetic alterations during propagation, making it necessary to do extensive testing before distribution. Based on results obtained with a flavivirus (tick-borne encephalitis virus) in an experimental animal system, we propose a novel live attenuated virus vaccination strategy consisting of the application of in vitro-synthesized infectious RNA instead of the live virus itself. When administered using the GeneGun, less than 1 ng of RNA was required to initiate replication of virus that was attenuated by a specifically engineered deletion and this induced a protective immunity in laboratory mice. Because this approach uses RNA, it does not have the potential drawbacks of DNA vaccines and thus combines the advantages of conventional live virus vaccines (for example, mimicking natural infection and inducing long-lasting immunity) with those of nucleic acid-based vaccines (for example, ease of production without a requirement for eukaryotic cell culture, stability and purity).

Measles outbreak linked to a minority group in Austria, 2008.

We report on a measles outbreak originating in an anthroposophic community in Austria, 2008. A total of 394 (94.9%) cases fulfilled the outbreak case definition including 168 cases affiliated to the anthroposophic community. The source case was a school pupil from Switzerland. The Austrian outbreak strain was genotype D5, indistinguishable from the Swiss outbreak strain. A school-based retrospective cohort study in the anthroposophic school demonstrated a vaccine effectiveness of 97.3% in pupils who had received a single dose of measles-containing vaccine and 100% in those who had received two doses. The vaccination coverage of the cases in the anthroposophic community was 0.6%. Of the 226 outbreak cases not belonging to the anthroposophic community, the 10-24 years age group was the most affected. Our findings underline the epidemiological significance of suboptimal vaccination coverage in anthroposophic communities and in older age groups of the general population in facilitating measles virus circulation. The findings of this outbreak investigation suggest that the WHO European Region is unlikely to achieve its 2010 target for measles and rubella elimination.

First results of a national external quality assessment scheme for the detection of SARS-CoV-2 genome sequences.

BACKGROUND: Broad and decentralised testing of SARS-CoV-2 RNA genomes is a WHO-recommended strategy to contain the SARS-CoV-2 pandemic by identifying infected cases in order to minimize onward transmission. With the need to increase the test capacities in Austria, nation-wide numerous laboratories rapidly implemented assays for molecular detection of SARS-CoV-2 based on real-time RT-PCR assays. The objective of this study was to monitor reliability of the laboratory results for SARS-CoV-2 RNA detection through an external quality assessment (EQA) scheme. METHODS: For this, the Center for Virology, Medical University of Vienna was tasked by the Federal Ministry of Social Affairs, Health, Care and Consumer Protection to perform the first Austrian EQA on SARS-CoV-2 which was organised in cooperation with the Austrian Association for Quality Assurance and Standardization of Medical and Diagnostic Tests (ÖQUASTA). Data were analysed on the basis of qualitative outcome of testing in relation to the nucleic acid (NA) extraction and detection methods used. RESULTS AND CONCLUSION: A total of 52 laboratories participated, contributing results from 67 test panels comprising 42 distinct combinations of NA extraction and PCR reagents. By testing 3 positive (CT values: S1, 28.4; S2, 33.6; S3, 38.5) and 1 negative sample, no false-positive results were obtained by any of the laboratories. Otherwise, 40/67 tests (60 %) detected all positive samples correctly as positive, but 25/67 tests (37 %) did not detect the weakest positive sample (S3), and 3 % reported S2 and S3 as false-negative. Improvement in test sensitivity by focusing on NA extraction and/or PCR-based detection is recommended.

Transmission of hepatitis C virus in an orthopedic hospital ward.

Healthcare-associated infections with hepatitis C virus (HCV) hitherto have been observed mainly in hemodialysis settings as well as in hematology and oncology wards. In this communication, molecular and epidemiologic investigations to elucidate an HCV outbreak in an orthopedic ward are reported. One hundred and thirty-five patients hospitalized in the ward and 104 staff members were tested. In addition to extensive epidemiologic reviews and hygienic inspections, direct sequencing of HCV PCR fragments and phylogenetic analysis of more than 300 partial HCV sequences obtained by end-point limiting-dilution real-time PCR assay were carried out. Six patients were infected with very closely related HCV variants. Patient-to-patient spread of the virus was inferred to have started from one patient with previous HCV infection to the other five patients during their hospital stay. Inspections did not reveal substantial breaches in basic infection control practices and did not identify a specific activity that might have led to nosocomial transmission. As a result of the investigations, the hospital corrected the documentation of all medical and nursing activities undertaken in the ward, abandoned the use of all multidose saline and other medication vials, and included explicitly recommendations for the safe preparation and administration of injectable drugs into internal infection control guidelines. Thereafter, no further nosocomial transmissions of HCV have been recorded in the orthopedic ward. The events observed suggest that nosocomial transmission of HCV is not limited to hemodialysis, hematology or oncology settings, and they also reinforce the mandatory adherence to basic infection control practices.

Measles outbreak in Styria, Austria, March-May 2009.

In the last week of March 2009, five measles cases among students of an anthroposophic school were reported to the public health authorities in the Austrian province of Styria where only five cases had been reported in the whole of 2008. A descriptive epidemiological investigation of the measles outbreak was performed. Between 2 March and 10 May 2009, 37 cases of measles were identified in Styria: 33 confirmed outbreak cases and four probable outbreak cases. The measles outbreak spread from the general population (12 cases) to an anthroposophic community (25 cases). Cases outside of the anthroposophic community were mostly over 10 years of age (10/12). Thirty-five cases were unvaccinated, and two of the 37 had received one dose of measles, mumps, rubella vaccine. Following a measles outbreak in Salzburg in 2008 with 394 cases, this outbreak reemphasises the continued need for additional vaccination campaigns in population groups over the age of 10 years.

Ongoing rubella outbreak in Austria, 2008-2009.

Since October 2008, a total of 143 cases of rubella have affected the two Austrian provinces Styria and Burgenland. The index case occurred in mid-October 2008, but was not notified to the public health authorities until February 2009, when the Austrian Agency for Health and Food Safety was asked to investigate a cluster of 32 rubella cases (24 laboratory-confirmed and eight clinically suspected cases). No case of rubella had been reported in the two affected provinces between February 2007 - when statutory notification for rubella was implemented - and mid-October 2008. 113 of the 143 cases (79%) were confirmed: 101 (89.3% of the 113 cases) clinical-laboratory confirmed and 12 clinical-epidemiological confirmed. Thirty cases fulfilled the criteria of a probable outbreak case only (laboratory results or data on epidemiological link are pending). For 140 outbreak cases data on age was known; the median age was 19 years (range: 2-60 years). 20 cases occurred in soldiers in seven military camps in the area. 55 cases (38.5 %) were female. One case of a laboratory-confirmed rubella infection, affecting an unvaccinated pregnant 18-years old native Austrian in the early first trimenon of pregnancy, led to voluntary abortion

Mumps outbreak in young adults following a festival in Austria, 2006.

Mumps is not a mandatorily notifiable disease in Austria. However, in the first week of May 2006, a sudden increase in serologically confirmed cases of mumps, confined to three public health districts of the southern Austrian province of Carinthia, was identified by the Austrian Reference laboratory for MMR. An epidemiological investigation of this cluster of mumps cases was performed. A total of 214 cases fulfilled the outbreak case definition; 143 cases were laboratory confirmed and 71 cases were epidemiologically linked and fulfilled the clinical picture of the case definition. The vaccination status was known for 169 patients. Nearly half of the cases for whom the vaccination status was known occurred in non-vaccinated persons, another 40% were vaccinated with one dose of the vaccine and 11% had received two doses. Only four mumps cases occurred in children aged 14 years or younger, indicating that the vaccination coverage and the acceptance of the recommended childhood vaccinations have strongly improved within the past 15 years. Vaccination scheme failure but not vaccine failure is primarily to blame for this mumps outbreak.

Nonparametric identification and maximum likelihood estimation for hidden Markov models.

Nonparametric identification and maximum likelihood estimation for finite-state hidden Markov models are investigated. We obtain identification of the parameters as well as the order of the Markov chain if the transition probability matrices have full-rank and are ergodic, and if the state-dependent distributions are all distinct, but not necessarily linearly independent. Based on this identification result, we develop a nonparametric maximum likelihood estimation theory. First, we show that the asymptotic contrast, the Kullback-Leibler divergence of the hidden Markov model, also identifies the true parameter vector nonparametrically. Second, for classes of state-dependent densities which are arbitrary mixtures of a parametric family, we establish the consistency of the nonparametric maximum likelihood estimator. Here, identification of the mixing distributions need not be assumed. Numerical properties of the estimates and of nonparametric goodness of fit tests are investigated in a simulation study.

Seasonal rhythm of the plasma level of alpha-melanocyte stimulating hormone.

The present results indicate the presence of a seasonal rhythm of immunoreactive alpha-melanocyte stimulating hormone (alpha-MSH) in 20- to 40-year-old subjects of skin type I (light color of skin and eyes, red hair, no tanning after sun exposure) and skin type II (light color of skin, eyes, and hair, rare tanning) with raised levels of alpha-MSH in summer and low levels in winter. With increasing age of the investigated subjects, the seasonal rhythm seems to be lost. In subjects with skin type III (light skin, brown eyes and black hair, strong pigmentation after sun exposure) alpha-MSH shows only insignificant variations over the whole year. A seasonal rhythm of ACTH could not be demonstrated. A diurnal rhythm could be seen for ACTH, but not for alpha-MSH. To summarize, one can suppose that the seasonal rhythm of alpha-MSH is controlled by a varying UV exposure of the integument which is different over the whole year.

The relationship between alpha-MSH level and coat color in white Camarque horses.

White horses are subject to age-dependent coat depigmentation. They are dark gray or black at birth and lose their coloring between their second and fourth year. Beginning at about age 10 their coat takes on a characteristic silver-gray coloring. The purpose of this paper was to find out to what extent the endogenic alpha-MSH level changes with the change in pigmentation. alpha-MSH plasma levels were determined by radioimmunologic analysis in 3 age groups of white Camarque horses: age group 1 consisted of dark horses with a mean age of 1.2 years and a mean alpha-MSH level of 106.4 pg/ml +/- 18.2, age group 2 consisted of gray horses with a mean age of 7.5 years and with a mean alpha-MSH level of 73.6 pg/ml +/- 4.8, and age group 3 consisted of silver-gray horses with a mean age of 13.5 years and a mean alpha-MSH level of 65.0 pg/ml +/- 5.3. Highly significant differences (p less than 0.001) were found between the means of age group 1 and age group 2 and between the means of age group 1 and age group 3. Determination of the ACTH plasma levels in this breed of horses showed no statistically significant differences between the various age groups. Determination of alpha-MSH and ACTH levels in a control group (n = 56) of other breeds of horses (10 black, 28 brown, and 18 sorrel) resulted in no significant differences for either hormone with regard to age or coat color. On the basis of these results it may be concluded that the degree of coat pigmentation in white Camarque horses correlates directly with the alpha-MSH plasma level.

Effect of dexamethasone on nuclear envelope nucleoside triphosphatase in fibroblasts 3T3 and melanoma cells MMLI.

Glucocorticoids are known to influence DNA and RNA synthesis in skin fibroblasts. In a novel approach to study this effect, we investigated the influence of the hormone analogue dexamethasone on the activity of nuclear envelope-associated nucleoside triphosphatase (NTPase) in intact cell systems (3T3 fibroblasts and MMLI melanoma cells). The NTPase is thought to be responsible for regulation of nucleocytoplasmic transport of mRNA. [3H]Dexamethasone was found to bind to nuclear ghosts at a density comparable with that of nuclear pores in this cellular fraction. Incubation of the cells for 48 h in the presence of different concentrations of dexamethasone resulted in a marked decrease of NTPase activity. Already concentrations as low as 0.1 ng/ml (3T3) or 1 ng/ml (MMLI) reduced the NTPase activity by approximately 50%. These results suggest that nuclear envelope NTPase is a site at which glucocorticoids regulate gene expression.

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections in health care workers (HCWs): guidelines for prevention of transmission of HBV and HCV from HCW to patients.

The transmission of viral hepatitis from health care workers (HCW) to patients is of worldwide concern. Since the introduction of serologic testing in the 1970s there have been over 45 reports of hepatitis B virus (HBV) transmission from HCW to patients, which have resulted in more than 400 infected patients. In addition there are six published reports of transmissions of hepatitis C virus (HCV) from HCW to patients resulting in the infection of 14 patients. Additional HCV cases are known of in the US and UK, but unpublished. At present the guidelines for preventing HCW to patient transmission of viral hepatitis vary greatly between countries. It was our aim to reach a Europe-wide consensus on this issue. In order to do this, experts in blood-borne infection, from 16 countries, were questioned on their national protocols. The replies given by participating countries formed the basis of a discussion document. This paper was then discussed at a meeting with each of the participating countries in order to reach a Europe-wide consensus on the identification of infected HCWs, protection of susceptible HCWs, management and treatment options for the infected HCW. The results of that process are discussed and recommendations formed. The guidelines produced aim to reduce the risk of transmission from infected HCWs to patients. The document is designed to complement existing guidelines or form the basis for the development of new guidelines. This guidance is applicable to all HCWs who perform EPP, whether newly appointed or already in post.

The interactions of the flavivirus envelope proteins: implications for virus entry and release.

Viral membrane proteins play an important role in the assembly and disassembly of enveloped viruses. Oligomerization and proteolytic cleavage events are involved in controlling the functions of these proteins during virus entry and release. Using tick-borne encephalitis virus as a model we have studied the role of the flavivirus envelope proteins E and prM/M in these processes. Experiments with acidotropic agents provide evidence that the virus is taken up by receptor-mediated endocytosis and that the acidic pH in endosomes plays an important role for virus entry. The envelope glycoprotein E undergoes irreversible conformational changes at acidic pH, as indicated by the loss of several monoclonal antibody-defined epitopes, which coincide with the viral fusion activity in vitro. Sedimentation analysis reveals that these conformational changes lead to aggregation of virus particles, apparently by the exposure of hydrophobic sequence elements. None of these features are exhibited by immature virions containing E and prM rather than E and M. Detergent solubilization, sedimentation, and crosslinking experiments provide evidence that prM forms a complex with protein E which prevents the conformational changes necessary for fusion activity. The functional role of prM before its endoproteolytic cleavage by a cellular protease thus seems to be the protection of protein E from acid-inactivation during its passage through acidic trans Golgi vesicles in the course of virus release.

Levels of dopachrome tautomerase in human melanocytes cultured in vitro.

Several reports have been published about the level of activity and possible functions of dopachrome tautomerase (DCT) in mouse melanoma cells. Data about the levels of this activity in human melanocytes in culture are still scarce, and, as far as we know, a comparison between mouse and human melanocytes, or between normal and malignant melanocytes, has never been published. We have measured the tyrosinase and DCT activities, as well as the melanin content, in mouse Cloudman melanoma cells, two lines of human melanoma, and three lines of normal human melanocytes obtained from fetal skin. Although more cell lines should be tested to draw a general conclusion, our results suggest that normal melanocytes contained much higher tyrosinase activity and melanin content but lower DCT activity than malignant melanocytes. The two lines of human melanoma cells tested had lower levels of DCT activity than Cloudman melanoma cells. Finally, the low level of DCT activity found in normal human melanocytes cultured in vitro cannot be explained by any of the necessary stimulatory factors added to the cell culture media.

[Radioimmunoassay of dehydroepiandrosterone and 5-androstene-3-beta, 17-beta-diol in the plasma of psoriatics and controls]. / Radioimmunologische Bestimmung von Dehydroepiandrosteron und 5-Androsten-3 beta, 17 beta-diol im Plasma von Psoriatikern und Kontrollpersonen.

In the plasma of psoriatics and controls the steroids dehydroepiandrosterone and 5-androstene-3 beta, 17 beta-diol were determined by radioimmunoassay. Corresponding earlier findings obtained by photometric methods in psoriatics the plasma level of dehydroepiandrosterone is increased and that of androstenediol is decreased.

[Bone findings in psoriasis]. / Knochenbefunde bei Psoriasis.

Three female patients out of 40 psoriatics examined with scintigraphical methods (Tc-diphosphonate) were found to have a diffuse and circumscribed pathological increase of nuclide at the skull. These abarticular signes of proliferation at the bone-area indicate an early affection of skeleton of patients with psoriasis which is similar to the joint-scan that is mostly obtained in positive bone-scan.

Effect of the dose of ultraviolet radiation on the pigment formation by human melanocytes in vitro.

Human melanocytes were cultivated under different conditions with phorbol ester (TPA), or with bovine pituitary extract (BPE). The cells altered their morphology with the different culture conditions. With TPA they were predominantly bipolar, while with BPE most of the cells had a dendritic cell shape. In order to investigate the effect of UV irradiation, the cells were irradiated with 50, 100 and 200 mJ/cm2 UVA/B. After irradiation with 200 mJ/cm2 UVA/B the cells cultured with TPA also showed a dendritic shape. We determined the tyrosinase activity, the cellular melanin content and the cell number 3 days after irradiation. In all cases the number of cells decreased depending on the UVA/B doses. In melanocytes we found a marked increase in tyrosinase activity and melanin content after irradiation with 200 mJ/cm2. The UV-induced effect on tyrosinase activity was higher in melanocytes cultured with BPE than in those cultured with TPA. The results were compared with two human melanoma cell lines. Only little pigment formation could be measured in the tested melanoma cell lines without change after UV irradiation.