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A cluster of seven human cases of listeriosis occurred in Austria and in Germany between April 2011 and July 2013. The Listeria monocytogenes serovar ( SV) 1/2b isolates shared pulsed-field gel electrophoresis ( PFGE) and fluorescent amplified fragment length polymorphism (f AFLP) patterns indistinguishable from those from five food producers. The seven human isolates, a control strain with a different PFGE/f AFLP profile and ten food isolates were subjected to whole genome sequencing ( WGS) in a blinded fashion. A gene-by-gene comparison (multilocus sequence typing ( MLST)+) was performed, and the resulting whole genome allelic profiles were compared using SeqSphere+ software version 1.0. On analysis of 2298 genes, the four human outbreak isolates from 2012 to 2013 had different alleles at ≤6 genes, i.e. differed by ≤6 genes from each other; the dendrogram placed these isolates in between five Austrian unaged soft cheese isolates from producer A (≤19-gene difference from the human cluster) and two Austrian ready-to-eat meat isolates from producer B (≤8-gene difference from the human cluster). Both food products appeared on grocery bills prospectively collected by these outbreak cases after hospital discharge. Epidemiological results on food consumption and MLST+ clearly separated the three cases in 2011 from the four 2012-2013 outbreak cases (≥48 different genes). We showed that WGS is capable of discriminating L. monocytogenes SV1/2b clones not distinguishable by PFGE and f AFLP. The listeriosis outbreak described clearly underlines the potential of sequence-based typing methods to offer enhanced resolution and comparability of typing systems for public health applications. [ABSTRACT FROM AUTHOR]

Purpose: Although an increase in burden of disease has frequently been reported for Clostridium difficile infection (CDI), specific data on the effect of CDI on a patient's risk of death or overall hospital mortality are scarce. Therefore, we performed a prospective cohort study to analyse the effect of CDI on the risk of pre-discharge all-cause death in all inpatients with CDI compared to all inpatients without CDI during 2009 in a single hospital. Methods: Clostridium difficile infection was defined as by the European Society of Clinical Microbiology and Infectious Diseases. Data were collected from the medical charts of CDI patients and from the hospital discharge data of non-CDI and CDI patients. The effect measures of CDI used to compute the risk of pre-discharge all-cause death were risk ratio, attributable risk, mortality fraction (%) and population attributable risk percentage. Co-morbidity was categorized using the Charlson co-morbidity score in which a value of ≤2 was defined as low co-morbidity and that of >2 as moderate/severe co-morbidity. A stratified analysis and a Poisson regression model were applied to adjust for the effects of the risk factors sex, age and severity of co-morbidity. Results: A total of 185 hospitalized patients with CDI were compared to 38,644 other hospitalized patients without CDI admitted between 1 January 2009 and 31 December 2009. The mean age of the CDI and non-CDI patients was 74.3 (range 72.3-76.4) and 51.9 (range 51.6-52.1) years, respectively. Of the 185 CDI, 136 (73.5 %) and 49 (26.5 %) were categorized with low and high co-morbidity, respectively, versus 32,107 (83.4 %) and 6,352 (16.5 %), respectively, in non-CDI patients. Overall, 24 of the 185 CDI patients (13 %) versus 1,021 of the 38,459 non-CDI patients (2.7 %) died during their hospital stay, resulting in a relative risk of pre-discharge death of 4.89 [95 % confidence interval (CI) 3.35-7.13] for CDI patients, a CDI attributable risk of death of 10.3 per 100 patients and a CDI attributable fraction of 79.5 % (95 % CI 70.1-86 %). After adjustment for age, sex and co-morbidity the relative risk of pre-discharge death was 2.74 (95 % CI 1.82-4.10; p < 0.0001) for patients with CDI, and the proportion of hospital deaths due to CDI was 1.72 (95 % CI 1.22-2.05). Conclusion: The results of this study lead to the conclusion that hospitalized patients with CDI are-independent of age, sex and co-morbidity severity-2.74-fold more likely to die during their hospital stay than all other hospitalized patients. The eradication of CDI in the hospital could have prevented 1.72 % of in-hospital deaths in our study population during the 1 year of the study. [ABSTRACT FROM AUTHOR]

An outbreak of hepatitis A affecting 21 residents of an Austrian city occurred from the end of November 2007 until mid-January 2008. A case series investigation suggested the consumption of food purchased from supermarket X as the common link. A food handler employed in the delicatessen department of that supermarket had been serologically diagnosed with hepatitis A on 28th November 2007. During the infectious period of approximately 3 weeks, he worked on 11 days. Interviews with the other cluster cases revealed that the hepatitis A virus (HAV)-infected food handler did not practice appropriate hand hygiene. The investigation revealed no other possible source of infection. We hypothesize that the food of the delicatessen department contaminated by the HAV-infected food handler during his infectious period was the source of the outbreak. The district public health authority recommended the reinforcement of hygiene precautions, i.e., access to viricidal hand disinfectant and the use of disposable gloves and single-use paper towels, in the involved supermarket. The federal ministry of health recommended HAV vaccination for all food handlers in food production and gastronomy companies; this recommendation was included in the Austrian national vaccination plan 2008, even though the vaccination of food handlers is costly and its cost-effectiveness is not proven. Appropriate and regular hand hygiene, particularly after toilet visits, is the most effective measure for preventing HAV transmission. [ABSTRACT FROM AUTHOR]

Norovirus is increasingly being recognized as a leading cause of foodborne disease. Nevertheless, welldocumented foodborne outbreaks due to norovirus are rarely found in the literature. A retrospective cohort study was conducted for identifying the source of a gastroenteritis outbreak. A total of 325 persons were identified as the atrisk group. The overall attack rate was 56% (182/325). Of the four working days of possible foodborne exposure to norovirus (Monday till Thursday), Wednesday (risk ratio [RR]: 18.82; 95%CI 11.82–29.96) and Thursday (RR 2.14; 95%CI 1.65–2.79) turned out to be the most likely days on which infections with norovirus occurred. The day-by-day food specific cohort analyses yielded consumption of salad on Wednesday (adjusted RR 2.82; 95%CI 1.0–7.94) to be associated with highest risk of illness. The most likely source of food contamination is a kitchen assistant having prepared salad manually. She fell ill with symptoms of gastroenteritis on Wednesday during the early working hours and continued working. Human stool samples obtained from five out of six outbreak cases, including the sick kitchen assistant, were RT-PCR positive for norovirus genotype GGII.7 (Leeds-like). This foodborne norovirus outbreak underlines the drastic consequences of neglecting the rules of basic kitchen hygiene. Food handlers working despite manifest diarrhea or vomiting – often in fear of job loss – are a common cause of foodborne norovirus outbreaks. [ABSTRACT FROM AUTHOR]

BackgroundThe COVID-19 pandemic was largely driven by genetic mutations of SARS-CoV-2, leading in some instances to enhanced infectiousness of the virus or its capacity to evade the host immune system. To closely monitor SARS-CoV-2 evolution and resulting variants at genomic-level, an innovative pipeline termed SARSeq was developed in Austria.AimWe discuss technical aspects of the SARSeq pipeline, describe its performance and present noteworthy results it enabled during the pandemic in Austria.MethodsThe SARSeq pipeline was set up as a collaboration between private and public clinical diagnostic laboratories, a public health agency, and an academic institution. Representative SARS-CoV-2 positive specimens from each of the nine Austrian provinces were obtained from SARS-CoV-2 testing laboratories and processed centrally in an academic setting for S-gene sequencing and analysis.ResultsSARS-CoV-2 sequences from up to 2,880 cases weekly resulted in 222,784 characterised case samples in January 2021-March 2023. Consequently, Austria delivered the fourth densest genomic surveillance worldwide in a very resource-efficient manner. While most SARS-CoV-2 variants during the study showed comparable kinetic behaviour in all of Austria, some, like Beta, had a more focused spread. This highlighted multifaceted aspects of local population-level acquired immunity. The nationwide surveillance system enabled reliable nowcasting. Measured early growth kinetics of variants were predictive of later incidence peaks.ConclusionWith low automation, labour, and cost requirements, SARSeq is adaptable to monitor other pathogens and advantageous even for resource-limited countries. This multiplexed genomic surveillance system has potential as a rapid response tool for future emerging threats.

Background and Aims: Micro-elimination projects targeted to specific hepatitis C virus (HCV) risk populations have been successful. Systematic identification of persons with HCV viremia, regardless of risk group, based on already available laboratory records may represent an effective macroelimination approach to achieve global HCV elimination., Methods: Persons with a last positive HCV-RNA PCR result between 2008-2020 in the reference virology laboratories in eastern Austria were identified. First, (i) we described their demographic characteristics, (ii) we systematically recalled persons to the respective centers and (iii) started antiviral treatment if HCV-RNA viremia was confirmed, and (iv) recorded sustained virologic response (SVR). This interim report includes the preliminary results from 8 participating centers., Results: During the study period 22,682 persons underwent HCV-RNA PCR testing, 11,216 (49.4%) were positive at any point in time, and 6006 (26.5%) showed detectable HCV-RNA at the last PCR test, suggesting ongoing HCV viremia. At the time of this interim report, 2546/6006 HCV-RNA PCR(+) persons were evaluated: 443/2546 (17.4%) had died, 852/2546 (33.5%) had invalid contact data, and 547/2546 (21.5%) had achieved SVR between data retrieval and recall. Contact could be established in 236/704 (33.5%) of the remaining target population with 97/236 (41.1%) presenting at the clinic for treatment evaluation. Ultimately, 71/236 (30.1%) started antiviral treatment and SVR was documented in 47/71 (66.2%)., Conclusion: This ELIMINATE project based on systematic assessment of HCV-RNA PCR-records, identified 6006 persons with potential persisting HCV viremia. Invalid contact data and missed visits for treatment evaluation were the main barriers towards HCV elimination within this project. Importantly, many subjects with HCV viremia lost to follow-up were successfully linked to care and started antiviral treatment., (© 2023. The Author(s).)

Following an increase in diphtheria cases in Europe since 2022, we retrospectively estimated the prevalence of seroprotection against diphtheria and tetanus in 10,247 Austrian residents (population: 8,978,929) voluntarily tested between 2018 and 2022. Lack of seroprotection against diphtheria was found in 36% compared with 4% against tetanus. The geometric mean antibody concentration against tetanus was 7.9-fold higher compared with that for diphtheria. Raising awareness of regular booster vaccinations against diphtheria in combination with tetanus and pertussis is urgently needed.

We aim to identify those measures that effectively control the spread of SARS-CoV-2 in Austrian schools. Using cluster tracing data we calibrate an agent-based epidemiological model and consider situations where the B1.617.2 (delta) virus strain is dominant and parts of the population are vaccinated to quantify the impact of non-pharmaceutical interventions (NPIs) such as room ventilation, reduction of class size, wearing of masks during lessons, vaccinations, and school entry testing by SARS-CoV2-antigen tests. In the data we find that 40% of all clusters involved no more than two cases, and 3% of the clusters only had more than 20 cases. The model shows that combinations of NPIs together with vaccinations are necessary to allow for a controlled opening of schools under sustained community transmission of the SARS-CoV-2 delta variant. For plausible vaccination rates, primary (secondary) schools require a combination of at least two (three) of the above NPIs., (© 2022. The Author(s).)

Puumala orthohantavirus (PUUV) has a wide distribution throughout Europe. Distinctive temporal patterns of spillover into the human population are related to population dynamics of the reservoir host, the bank vole ( Clethrionomys glareolus ). As the rodent host is tied to specific habitats with small individual ranges, PUUV genetic diversity is also highly correlated with geographic distance. Using sequenced portions of viral S and M segments, we determined whether geographic clusters were supported. Human cases of PUUV infections are concentrated in southeastern Austria. We detected four distinct genotypes: two genotypes of the Alpe-Adria (ALAD) lineage typically associated with southeast Europe, and two sublineages of the Central Europe (CE) lineage. One cluster of CE genotypes represents a phylogenetically distinct sublineage compared to previously reported CE clades, and extends the boundary of the CE lineage further south than previously reported.

Pertussis is a vaccine-preventable disease, and its recent resurgence might be attributable to the emergence of strains that differ genetically from the vaccine strain. We describe a novel pertussis isolate-based surveillance system and a core genome multilocus sequence typing scheme to assess Bordetella pertussis genetic variability and investigate the increased incidence of pertussis in Austria. During 2018-2020, we obtained 123 B. pertussis isolates and typed them with the new scheme (2,983 targets and preliminary cluster threshold of <6 alleles). B. pertussis isolates in Austria differed genetically from the vaccine strain, both in their core genomes and in their vaccine antigen genes; 31.7% of the isolates were pertactin-deficient. We detected 8 clusters, 1 of them with pertactin-deficient isolates and possibly part of a local outbreak. National expansion of the isolate-based surveillance system is needed to implement pertussis-control strategies.

On 21 January 2019, public health authorities of two neighboring Austrian provinces reported an increase in measles cases. We investigated this occurrence to identify clusters of epidemiologically linked cases and the associated vaccination status in order to generate hypotheses on those factors explaining the size of the measles clusters. Probable cases were residents of the provinces of Styria or Salzburg with clinical presentation of measles after 1 January 2019 who were linked to a confirmed case using RNA virus detection. We collected data on age, rash onset, certificate-based vaccination status and reasons for being unvaccinated. Contact history was used to identify chains of transmission. By 11 March, we identified 47 cases, with 40 (85.1%) in unvaccinated patients. A cluster of 35 cases with a median age of seven years (IQR: 1-11) occurred between 9 January and 20 February in the province of Styria due to one transmission chain with four case generations. Of 31 vaccine-eligible cases, 25 (80.6%) were unvaccinated, of which 13 refused vaccination. Between 10 January and 1 March, we identified 12 cases as part of five unlinked clusters in the province of Salzburg. Each of these five clusters consisted of two generations: the primary case and the successive cases (median age: 22 years, IQR: 11-35). Eleven of 12 cases occurred in unvaccinated patients, with none of the 11 having a vaccination-refusing attitude. An extended measles cluster in a vaccination-refusing community, compared to five short-lived clusters concurrently occurring in the neighboring province, illustrates how vaccine refusal may hamper control of transmission.

Superspreading events shaped the coronavirus disease 2019 (COVID-19) pandemic, and their rapid identification and containment are essential for disease control. Here, we provide a national-scale analysis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) superspreading during the first wave of infections in Austria, a country that played a major role in initial virus transmissions in Europe. Capitalizing on Austria's well-developed epidemiological surveillance system, we identified major SARS-CoV-2 clusters during the first wave of infections and performed deep whole-genome sequencing of more than 500 virus samples. Phylogenetic-epidemiological analysis enabled the reconstruction of superspreading events and charts a map of tourism-related viral spread originating from Austria in spring 2020. Moreover, we exploited epidemiologically well-defined clusters to quantify SARS-CoV-2 mutational dynamics, including the observation of low-frequency mutations that progressed to fixation within the infection chain. Time-resolved virus sequencing unveiled viral mutation dynamics within individuals with COVID-19, and epidemiologically validated infector-infectee pairs enabled us to determine an average transmission bottleneck size of 10 3 SARS-CoV-2 particles. In conclusion, this study illustrates the power of combining epidemiological analysis with deep viral genome sequencing to unravel the spread of SARS-CoV-2 and to gain fundamental insights into mutational dynamics and transmission properties., (Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution License 4.0 (CC BY).)

This is a report on the first identified cases of coronavirus disease 2019 (COVID-19) in Austria. The first documented case was a person who stayed in Kühtai, Tyrol, from 24 to 26 January 2020, and had been infected by a Chinese instructor in Starnberg (Germany) between 20 and 22 January. This counts as a German case since her diagnosis was eventually made in Munich (Germany) on 28 January. On 25 February, two cases imported from Italy were diagnosed in Innsbruck but again no secondary cases were identified in Austria. The first three infections of Austrian inhabitants were detected on 27 February in Vienna. The two resulting clusters finally included 6 (source of initial infection unknown) and 61 cases. Most likely, Italy was the source of the latter cluster. On 12 March the first fatal case of COVID-19 in Austria was reported, a 69-year-old Viennese who died in a Vienna hospital after returning from a cruise ship tour in Italy. On 6 March three autochthonously acquired cases were reported in the Tyrol, all related to the ski resort Ischgl. Of the first 14 Islandic COVID-19 cases infected in Ischgl, 11 had already returned to Iceland on 29 February. We consider that the incriminated barkeeper, who tested PCR positive on 7 March, was neither the primary case nor a superspreader. In our opinion, undetected transmission of SARS-CoV‑2 had been ongoing in Ischgl prior to the first laboratory confirmed cases. Our data also underline that the introduction of SARS-CoV‑2 into Austria was not one single event.

We investigated the prevalence of Hepatitis E Virus (HEV), Leptospira and Ascaris suum (A. suum) seropositivity, and of nasal methicillin-resistant Staphylococcus aureus (MRSA) colonization among Austrian practising veterinarians, and assessed the association with occupational swine livestock exposure. The 261 participants completed a questionnaire on demographics, intensity of occupational swine livestock contact and glove use during handling animals and their secretions. Participants' blood samples were tested for HEV, Leptospira and A. suum seropositivity and nasal swabs cultured for MRSA. We compared swine veterinarians (defined as >3 swine livestock visits/week) to non-swine veterinarians (≤3 swine livestock visits/week) with regard to the outcomes through calculating prevalence ratio (PR) and 95% confidence interval (CI). Furthermore, the relationship between occupational swine livestock contact and the study outcomes was examined by age (3 occupational swine livestock visits per week is associated with HEV and A. suum seropositivity and nasal MRSA colonization and that glove use may play a putative preventive role in acquiring HEV and A. suum. Further analytical epidemiological studies have to prove the causality of these associations., (© 2019 The Authors. Zoonoses and Public Health Published by Blackwell Verlag GmbH.)

Background: In February 2012 the ten-valent pneumococcal conjugate vaccine (PCV10) with a 2+1 doses schedule (3, 5, 12 or 14 months of age) without catch-up vaccination was introduced in Austria. We assessed direct and indirect vaccine effects on invasive pneumococcal disease (IPD) by a population-based intervention study., Methods: The study period was divided into pre- (2009-2011) and post-period (2013-2017, February), regarding 2012 as transition year. Outcomes were defined as PCV10 ST-IPD, the PCV10-related ST 6A and 19A IPD and non-PCV10 excluding ST 6A-/19A-IPD (NVT-IPD). We used national surveillance data and compared average monthly incidence rate (IR) between pre- and post-period among <5, 5-49 and ≥50 years old. Additionally, for the 5-49 and ≥50 years old, and the 50-59 and ≥60 years old, we analyzed monthly incidence data of the pre-, post-period, and estimated trend and level changes by using a segmented time-series regression., Results: The PCV-10 IPD was reduced by 58% (95% CI: 30%; 74%) and 67% (95% CI: 32%; 84%) among <5 and ≥50 years old; the reduction in ≥60 years was 71% (95% CI: 36%; 88%). There were no significant changes in the pre-post-rate or incidence trend of NVT-IPD in the <5 and ≥50 years old. ST-specific analyses revealed no ST 6A- and ST 19A IPD decline in any age-group, and a ST 8 IPD increase among ≥50 years old (IR ratio: 3.5; 95% CI: 1.7; 7.2). We found no vaccine effects among 5-49 years old., Conclusions: Our study adds to the evidence on direct and indirect protection of a childhood PCV10 vaccine program. Elderlies seem to benefit the most. Findings did not support PCV 10 cross-protection, but indicate replacement at least for ST 8 among the ≥50 years old. Follow-up analyses of IPD surveillance data are needed to fully characterize the magnitude of serotype replacement and further vaccine-attributable IPD reduction with time., Competing Interests: LR, DS, EK, MK, and HB did not receive any specific funding, their work was part of the national surveillance programm of the Austrian Agency for health and Food Safety. UW, JJ, EP are employed by the Medical University Vienna, which received an investigator initiated grant from Pfizer AG for cooperation with children hospitals in Austria. We thus confirm that we adhere to all Plos One policies on sharing data and material.

Between June-September 2018, 20 hepatitis A cases were notified in six counties in Sweden. Combined epidemiological and microbiological investigations identified imported frozen strawberries produced in Poland as the source of the outbreak. Sequence analysis confirmed the outbreak strain IB in the strawberries with 100 % identity and the respective batch was withdrawn. Sharing the sequence information internationally led to the identification of 14 additional cases in Austria, linked to strawberries from the same producer.

A prospective, noninterventional survey was conducted among Clostridium difficile positive patients identified in the time period of July until October 2012 in 18 hospitals distributed across all nine Austrian provinces. Participating hospitals were asked to send stool samples or isolates from ten successive patients with C.difficile infection to the National Clostridium difficile Reference Laboratory at the Austrian Agency for Health and Food Safety for PCR-ribotyping and in vitro susceptibility testing. A total of 171 eligible patients were identified, including 73 patients with toxin-positive stool specimens and 98 patients from which C. difficile isolates were provided. Of the 159 patients with known age, 127 (74.3%) were 65 years or older, the median age was 76 years (range: 9-97 years), and the male to female ratio 2.2. Among these patients, 73% had health care-associated and 20% community-acquired C. difficile infection (indeterminable 7%). The all-cause, 30-day mortality was 8.8% (15/171). Stool samples yielded 46 different PCR-ribotypes, of which ribotypes 027 (20%), 014 (15.8%), 053 (10.5%), 078 (5.3%), and 002 (4.7%) were the five most prevalent. Ribotype 027 was found only in the provinces Vienna, Burgenland, and Lower Austria. Severe outcome of C. difficile infection was found to be associated with ribotype 053 (prevalence ratio: 3.04; 95% CI: 1.24, 7.44), not with the so-called hypervirulent ribotypes 027 and 078. All 027 and 053 isolates exhibited in vitro resistance against moxifloxacin. Fluoroquinolone use in the health care setting must be considered as a factor favoring the spread of these fluoroquinolone resistant C. difficile clones.

We report on a cluster of shigellosis including 21 cases in refugees and two in local residents who worked in refugee transit centres, detected in Austria in 2015, between calendar weeks 29 and 47. The species isolated from the cluster cases, including one mixed infection, were S. sonnei (n = 13), S. flexneri (n = 10) and S. boydii (n = 1). Eleven of 18 tested isolates were extended spectrum beta-lactamase (ESBL)-positive, including five of six ciprofloxacin-resistant and three azithromycin-resistant isolates.

Background: Clostridium difficile infection is the leading cause of gastroenteritis-associated deaths in the industrialized world, followed by infection with norovirus., Methods: Using a cohort study design, we compared 90 inpatients with diarrhea due to C. difficile infection (CDI) with 180 inpatients with diarrhea due to other infectious agents (including 55% with norovirus infection) with respect to complications and all-cause mortality. The effects of age, severity of underlying diseases and additional infections were assessed by stratified analyses., Results: Diarrhea recurrence occurred 8.9 (95%CI: 2.9-27.3) times more often in CDI independent of age and severity of comorbidities. The all-cause mortality in CDI patients pre-discharge and at 30 and 180 days, respectively, was 20.0%, 17.0% and 42.3% versus 7.2%, 6.7% and 22.5% in non-CDI diarrhea patients. Among those patients with low comorbidities, who were younger than 65 years and without additional infections, the all-cause pre-discharge, 30-day and 180-day mortality risks were significantly higher for the CDI diarrhea patients than the non-CDI diarrhea patients. This association was not observed among patients with an older age, more severe comorbidities or additional infections., Conclusion: CDI results in higher all-cause mortality than diarrhea due to other infectious agents in younger patients with low comorbidities., (Copyright © 2013 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.)

Background: We investigated whether spa typing is useful for indicating the setting of methicillin-resistant Staphylococcus aureus (MRSA) acquisition (community or health care acquired), the clinical relevance (colonization or infection), the type of infection (invasive or noninvasive), and the clinical outcome., Methods: Between August 2006 and December 2009, 381 routinely diagnosed culture-confirmed MRSA-positive patients were included into a cross-sectional study at an 800-bed hospital., Results: Out of 159 patients with colonization, 27 (17%) acquired MRSA in the community (CA-MRSA) and 123 (77.4%) in health care settings (HA-MRSA), and, of the 222 patients with infections, 119 (53.6%) had HA-MRSA and 103 (46.4%) had CA-MRSA. The 10 most frequent spa types accounted for 68.2% of the 346 typed MRSA isolates: t190 (28.3%), t032 (16.5%), t041 (9.4%), t008 (8.4%), t001 (3.4%), t002 (2.9%), t044 (3.1%), t223 (2.1%), t015 (2.1%), t127 (1.3%)., Conclusion: Spa typing of routinely identified MRSA isolates is unsuitable to predict the likeliness of an infection, of an invasive infection, and the clinical outcome. Molecular criteria such as spa type or Panton-Valentine leukocidin positivity used for classifying MRSA as either belonging to a community or hospital clone are of limited value to indicate the setting, where the MRSA strain was actually acquired according to epidemiologic criteria., (Copyright © 2013 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.)

We report on an outbreak caused by Salmonella enteritidis phage type 4 (PT4) among 143 participants at a soccer camp in Austria in August 2010. The outbreak affected 34 persons, including 24 epidemiologically related cases and 10 laboratory-confirmed cases. Food-specific cohort analyses revealed spaetzle (homemade noodles) (relative risks (RR): 2.68; 95% CI: 1.13-6.45), hamburger (RR: 2.70; 95% CI: 1.13-6.45) and potato salad (RR: 2.91; 95% CI: 1.69-5.02) as the most biologically plausible infection sources. Eggs used as ingredients were considered to be the vehicle of infection for the outbreak strain. The sole egg producer supplying the hotel that housed the soccer camp participants with table eggs operated two flocks. One flock had been epidemiologically and microbiologically related to a previous S. enteritidis PT4 outbreak affecting the same Austrian province in the four months preceding the August outbreak. We hypothesize that eggs from this flock, already condemned for industrial use only, were falsely declared table eggs and sold among eggs from the non-banned flock causing the subsequent outbreak. In Austria, the illegal distribution of eggs designated for industrial use (i.e., false declaration of these eggs as table eggs) has been previously documented. Our findings underscore the potential of proper epidemiological outbreak investigation to identify the pitfalls of regulatory responses in risk management., (Copyright © 2012 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.)

Introduction: Neisseria meningitidis is a leading cause of meningitis and sepsis worldwide. Thus, monitoring the epidemiology of invasive meningococcal disease (IMD) is an important public health measure. The National Reference Centre for Meningococci at the Austrian Agency for Health and Food Safety is operating the laboratory-based surveillance database., Methods: IMD isolates from all over Austria are collected at the National Reference Centre for Meningococci, where the microorganism is characterised by serological and molecular methods, as well as by antimicrobial susceptibility testing. These laboratory-based surveillance data from 1995 to 2010 were analysed by time, place and person. Long-term and seasonal trends were analysed by log-linear regression, yielding an annual average percentage change (AAPC), and by cyclic regression models, applying either a simple linear or a negative binomial regression, including one sine and one cosine term., Results: Over the past 16 years, IMD incidence ranged between 0.73 and 1.41/100,000 persons, with a decreasing trend in Serogroup B IMD incidence (AAPC: -2.1%; p = 0.0396) and an increasing trend in Serogroup C IMD incidence (AAPC: +4.3%; p = 0.043). In 2010, 80 cases of IMD were recorded, corresponding to an incidence of 0.95/100,000 population. Ten deaths were registered, which results in a case-fatality of 12.5% and a mortality incidence of 0.12/100,000 population. The predominant serogroup in Austria was serogroup B, followed by serogroups C, Y and W-135., Discussion: Although the incidence of IMD in 2010 is below the average incidence rate over the last 15 years, serogroup C IMD in Austria is increasing. Within the previous 10 years two provinces initiated vaccination campaigns for a monovalent meningococcal conjugate vaccine, following the increasing trend of Sg C IMD incidence. An ongoing study on the impact of these vaccination campaigns on the IMD burden will yield further scientific evidence for supporting the introduction of this vaccine into the publicly funded childhood immunisation program.

In Austria, a country with a total population of approximately 8.3 million, the published estimates of influenza-associated deaths within the past decade are surprisingly high (up to 6000 deaths per year) when compared to neighbouring countries. The objective of our analysis was to provide reliable estimates of the annual influenza-related deaths in Austria. We estimated the seasonal influenza-related excess mortality by calculating the difference between all-cause mortality observed during the influenza season and the baseline values to be expected during that time span if increased influenza activity was absent. Increased influenza activity was defined as moderate, usual or high, categorized by the influenza activity index using weekly data from the Austrian sentinel clinical surveillance system. For obtaining estimates of baseline all-cause mortality, a cyclic regression model was applied to the time series data on weekly all-cause mortality from 2001 to 2009. Austrian seasonal influenza-related excess mortality peaked in the seasons 2002/2003 (1060 excess deaths), 2004/2005 (1102 excess deaths) and 2008/2009 (1192 excess deaths). The rising trend observed is in parallel with the increasing proportion of the Austrian population older than 65 years for the same time span (2001:15.5%; 2009: 17.5%). Our findings on seasonal influenza-related excess mortality are in accordance with the estimates from Germany and Switzerland, which were derived from a similar approach. In order to gain and to preserve higher compliance with influenza vaccination initiatives, it is essential to have reliable data on influenza-related mortality. Thus, the numbers presented so far by Austrian public health institutions must be challenged.

We report on a salmonellosis-outbreak due to Salmonella Enteritidis phage type 14b resistant to nalidixic acid (S. Enteritidis PT14b Nx) among residents and employees of a student residence in Austria, September 2010. The outbreak was described and analysed by a retrospective cohort study, and microbiological environmental investigations were conducted to identify the outbreak source(s) and the reservoir of the outbreak strain. A total of 66 persons fulfilled the outbreak case definition including 14 laboratory-confirmed cases. Food specific cohort-analyses by day revealed that consumption of potato salad (RR: 1.65, 95%CI: 1.35–2.01, p=0.001) and a cheese-sausage cold plate (RR: 2.24, 95%CI: 1.29–3.88, p=0.002) on 14 September was associated with being an outbreak case. We hypothesised that cross-contamination with S. Enteritidis PT14b Nx positive eggs had occurred during preparation of the potato salad and cold plate as a result of preparing in parallel egg-containing breaded cutlets on 14 September. A traced laying hen holding in eastern Austria was identified as the sole source of the consumable eggs in the student residence. By applying the legally mandated sampling method for epidemiological-related laying hen farms (one pooled dust sample à 150g, two paired boot swabs cultured separately), the outbreak strain could not be detected. Our findings, that legally required sampling methods for laying hen farms failed to detect the causative pathogen in a laying hen holding, despite an epidemiological link, underline the request stated by the European Food Safety Authority Panel on Biological Hazards for a more sensitive sampling plan in epidemiologically-associated laying hen flocks.

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.

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.

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

Between 1999 and 2007 1,388 stool specimens from patients with acute flaccid paralysis or aseptic meningitis were submitted to the Austrian reference laboratory for poliomyelitis. Samples (201) yielded non-poliovirus enterovirus in culture. One hundred eighty-one viruses were available for typing and 78 isolates which remained serologically untyped were further analyzed by CODEHOP-PCR and sequencing of the VP1 gene and the 5'-untranslated region (5'-UTR). Typing revealed an Echovirus 30 outbreak in northwestern Austria in 2000, which was in accordance with the situation in Europe, and no dramatic seasonal changes of Coxsackie viruses were observed. In 2002/2003 a small outbreak of enterovirus 71 (EV71), affected 12 patients in the province of Styria. This virus was identified as genotype C1 and appeared to be genetically distinct from the isolates observed in 2001/2002 in Vienna. In 2004 two unrelated cases occurred in Lower Austria, which were identified as genotype C4, which has been described associated with high mortality most recently in China. In contrast to the situation in Asia the detected EV71 cases were not associated with hand-foot-mouth disease, but with serous meningitis only. This was surprising as a recent publication suggested a reduced neurovirulence of C1 genotype in children in Norway, presumably due to alterations in 5'-UTR and polymerase gene. However, comparing the 5'-UTR of the Austrian isolates and established virulent reference strains to the Norwegian isolate and an attenuated EV71 laboratory strain we did not find an indication that the genotype C1 possesses a RNA structure in its 5'-UTR leading to reduced neurovirulence., ((c) 2008 Wiley-Liss, Inc.)

A foodborne norovirus outbreak occurred after a pre-Christmas celebration among a group of local foresters in Austria in December 2007. A total of 66 persons, 60 participants of the Christmas party and 6 kitchen staff members of the restaurant where the party took place, were identified as the at-risk cohort. Questioning of this cohort was performed by self-report questionnaires or telephone interviews (response rate of 95%). The outbreak attack rate was 33.3% (21 of 63 persons), including two of the kitchen staff. Three stool specimens yielded norovirus genogroup II. Univariate analysis revealed that exposure to a ham roll and pastry was possibly associated with risk of gastroenteritis (risk ratio [RR] of 4.45, 95% CI of 1.91 to 10. RR of 2.44, 95% CI of 0.93 to 6.39). After controlling for the effects of sex, age, and other food items with a log-linear model, ham roll remained significantly associated with disease risk (RR of 3.91, 95% CI of 1.57 to 9.76). Ham roll was most likely contaminated with norovirus during preparation by a disease-free kitchen assistant, whose infant became sick with laboratory-confirmed norovirus gastroenteritis 2 days before the party. Informing food handlers about the possible risk of food contamination with norovirus and training them in the appropriate measures of hand hygiene and environmental disinfection at the working place and at home are essential for preventing food-related norovirus outbreaks. Norovirus-infected household members of healthy food handlers must be considered a possible reservoir for foodborne norovirus outbreaks.

On June 13, 2007, the public health authority informed the Austrian Agency for Health and Food Safety about 40 children from two neighboring elementary schools who had fallen ill with abdominal cramps and vomiting on June 8. School milk products consumed on June 8 were suspected as the source of the outbreak. On June 8, the milk products provided by local dairy X to eight elementary schools and two nurseries. The short incubation period - all cases fell ill on the day on which the products were consumed - and the short duration of illness (1-2 days) strongly suggested intoxication. In order to identify the causative pathogen, its reservoir and the mode of transmission, a descriptive-epidemiological and microbiological investigation and a retrospective cohort study were conducted. Six of the 10 institutions served by dairy X completed questionnaires on demographics and food consumption. One school had a 79% response rate (203/258) and was chosen as the basis for our cohort study. A total of 166 of the 1025 children (16.2%) at the 10 institutions fulfilled the case definition. Consumption of milk, cacao milk or vanilla milk originating from dairy X was associated with a 37.8 times higher risk of becoming a case (95% CI: 2.3-116.5). Unopened milk products left over at the affected institutions yielded staphylococcal enterotoxins A and D. Six out of 64 quarter milk samples from three of 16 cows producing milk for dairy X tested positive for S. aureus. The isolates produced enterotoxins A and D, yielded genes encoding enterotoxins and D, and showed spa type t2953. S. aureus isolated from the nasal swab of the dairy owner harbored genes encoding enterotoxins C, G, H and I, and showed spa type t635. Our investigation revealed that the milk products produced in dairy X on June 7 were the source of the outbreak on June 8. The cows - not the dairy owner - the likely reservoir of the enterotoxin-producing S. aureus. From the risk assessment of the production process at the dairy, we hypothesize that staphylococcal toxin production took place during a 3-day period of storage of pasteurized milk prior to repasteurization for the production batch of 7.

An outbreak of Salmonella Enteritidis infection among high school graduates was associated with the 2008 three-week Summer Splash event in Turkey. A similar outbreak, caused by Salmonella Enteritidis PT6, affected 70 of 2879 graduates attending the 2007 Summer Splash event. A total of 103 cases of Salmonella Enteritidis were identified by passive and active case finding among the 8914 participants of the 2008 event. A case series investigation was performed. The cases originated from eight of the nine Austrian provinces. Among 59 laboratory-confirmed S. Enteritidis cases, the most commonly identified phage type was PT21 (72.9%), followed by PT6 (18.6%), PT7 and PT3 (3.4% each). To our knowledge, none of the published outbreaks of salmonellosis in the past 10 years has involved multiple phage types. Among the three hotels within the resort complex, the highest number of outbreak cases was identified among the students who stayed at Hotel A (n = 37), followed by Hotel B (n = 33) and Hotel C (n = 32). Eggs and egg-containing products frequently offered at meals in all three hotels were hypothesized as the source of infection. Reliable findings from investigation of imported outbreaks enable the appropriate response measures in the country of origin. As a consequence of the effective programs for reducing salmonella in domestic animals intended for human consumption in Austria, the number of imported cases will gain importance in the coming years, and salmonellosis will increasingly appear as traveler's diarrhoea.

Norovirus is increasingly recognized as a leading cause of outbreaks of foodborne disease. We report on an outbreak in Austria that reached a total of 176 cases, affecting pupils and teachers from four schools on a skiing holiday in a youth hostel in the province of Salzburg in December 2007. A questionnaire was sent to the four schools in order to obtain data from persons attending the school trip on disease status, clinical onset, duration of illness and hospitalization. A cohort study was undertaken to identify the sources of infection. The school trip attendees were interviewed by questionnaire or face-to-face on their exposure to food items from the menu provided by the hostel owner. Of the 284 school holiday-makers, 176 fitted the definition of an outbreak case (attack rate 61.9%). A total of 264 persons on the ski holiday participated in the cohort study (response rate 93%). The day-by-day food-specific analyses did not find any food items served on any of five days (December 8-12) of the holiday to be associated with infection risk. The day-specific risk analyses revealed Monday December 10 (RR: 9.04; 95% CI: 6.02-13.6; P < 0.001) and Tuesday December 11 (RR: 3.37; 95% CI: 2.56-4.43; P < 0.001) as the two most risky days for having being exposed to norovirus. According to the epidemiological investigation, airborne transmission of norovirus originating from the first vomiting case most probably initiated this outbreak; foodborne genesis was excluded. During recent years, norovirus has become increasingly established as the most important causative agent of epidemic gastroenteritis in holiday-makers all over Europe. Tourism is one of the primary industries in Austria. Timely involvement of the relevant public health authorities is essential in any outbreak of norovirus gastroenteritis, irrespective of its genesis.

We report on the first foodborne outbreak of Shigella sonnei described in Austria. On July 14 2008, AGES was informed of a cluster of 22 laboratory-confirmed cases of infection with S. sonnei restricted to public health district X in the province of Salzburg. All cases had attended a youth-group trip to a small village in the province of Tyrol from July 7 to July 9. An outbreak case among the trip participants was a person who (1) attended the trip and (2) fell ill with diarrhea in the period between July 8 and July 12. Among the 61 trip participants, 42 fitted the outbreak case definition, including 31 culture-confirmed cases. A household outbreak case was a person who (1) did not participate in the trip, (2) fell ill with diarrhea not before July 10 and (3) had household contact with an outbreak case between one and three days before onset of illness. Of the 11 household outbreak cases, 10 were tested by stool culture and four of these had a laboratory-confirmed S. sonnei infection. In addition, one of the two hostel staff tested positive for S. sonnei. All 36 isolates were biotype gl, lysotype 12, and were indistinguishable from each other by PFGE. A cohort study among the trip participants revealed a risk ratio of 2.71 for consumption of salad (on at least 1 of the 3 days of the trip) (95% CI: 1.38-5.32, P = 0.004). Among the 42cases, 34 could be explained by consumption of salad. The landlady of the hostel, who prepared the salad with bare hands, was a carrier and was assumed to be the source of contamination of the salad. Without proper epidemiological analytical investigation of this shigellosis outbreak, its association with food consumption would not have been identified.

Background: Norovirus is easily spread from person to person by the fecal-oral route and through aerosols or by vehicles such as contaminated food or water. The virus is able to survive in the environment for many days, which enables outbreaks to be prolonged. We describe a norovirus outbreak and its control measures in an Austrian secondary-level hospital during December 2006 - February 2007., Methods: A descriptive-epidemiological investigation of the outbreak was undertaken. We also determined outbreak costs, including the estimated lost revenue associated with department closures and the cost of sick leave and cleaning expenses. Selected stool specimens were tested for norovirus RNA., Results: In the hospital, 90 persons with symptoms and signs consistent with norovirus gastroenteritis with clinical onset between December 1, 2006 and February 13, 2007 were identified. Out of these, 56 patients and 14 persons among the hospital staff fulfilled the definition of an outbreak case (77.8%), and 20 cases (22.2%) were identified as non-outbreak cases including 13 community-acquired cases of norovirus gastroenteritis and 7 clinical-suspected cases of norovirus gastroenteritis associated with health care facilities other than the affected hospital. The Department of Internal Medicine was the mainly affected department (46 patient-cases and 6 staff-cases). Considering hospital patients, who have been hospitalised between December 1, 2006 and February 13, 2007 as cohort at risk of nosocomial norovirus infection, the nosocomial hospital outbreak attack-rate was 5.9% (56/947). A total of 120 hospital staff members worked in the period from December 1 to February 13, which makes an attack-rate among the hospital staff of 11.7% (14/120). Norovirus strain GII.4 variant 2006b was detected, which has been circulating widely in Europe since 2006. The total cost of the outbreak for the Department of Internal Medicine was 80,138., Conclusions: The significant disruption of patient care and the cost of this single nosocomial outbreak support strict implementations of adequate and timely control measures based on evidence-based recommendations.

Setting: In 2005-2006, the Austrian reference laboratory for tuberculosis (TB) identified multidrug-resistant (MDR) isolates from four cases of TB showing genotypes indistinguishable from each other., Objective: To clarify the chain of transmission of this MDR-TB strain., Design: An epidemiological case series investigation by reviewing TB notification reports and hospital discharge letters., Results: The 38-year-old primary case of the MDR-TB cluster had initially been identified as a case of non-MDR pulmonary TB in June 2004, 7 months after being detained for illegal immigration. In March 2005, he was lost to follow-up for 4 months. In June 2005, he presented with pulmonary and laryngeal TB due to MDR-TB. After discharge, the case was again lost to follow-up until April 2006, when he was readmitted with recurrent MDR-TB. A three-case cluster of pulmonary MDR-TB sharing the same strain as the primary case was detected in April 2006: the index case's 5-month-old daughter and a 25-year-old friend with a 6-month-old son., Conclusion: As MDR-TB has originated in the human immunodeficiency virus seronegative community in Austria, there is a clear need to implement national guidelines for the management of drug-resistant TB in Austria.

In order to assess the lethality of Clostridium difficile-associated disease (CDAD) and the PCR ribotypes prevalent in Austria, the Austrian Agency for Health and Food Safety requested isolates of C. difficile from patients in a structured but arbitrary sampling scheme. In the allocated period from February 2006 to January 2007, local hospital laboratories within each of the nine provinces were asked to submit C. difficile isolates from at least ten cases of CDAD. Confirmation of species identification, toxin detection, susceptibility testing against four antimicrobial agents and typing using a PCR ribotyping method were performed at the reference laboratory. In total, 149 isolates of putative C. difficile were submitted, from which 142 were included for study. Antimicrobial susceptibility patterns revealed resistance to clindamycin in 57% and high-level resistance to moxifloxacin in 38% of isolates tested. CDAD manifested as diarrhoea (including eight cases of bloody diarrhoea) in 126 cases (88.7%), as pseudomembranous colitis in 15 cases (10.6%) and as toxic megacolon in one case. Twelve of the 142 patients died within 30 days of specimen collection (8.45% lethality). A lethal outcome occurred in 2/15 cases (13.3%) when pseudomembranous colitis was present and in 10/126 cases (7.9%) in the absence of pseudomembranous colitis or toxic megacolon. Among the 142 isolates from 25 health-care facilities, 41 PCR ribotype patterns were found. The most frequent ribotypes were AI-5 (including six lethal cases out of 26 patients), 014 (two out of 24) and 053 (one out of 24). The typing patterns demonstrated the occurrence of clusters in hospitals.

An outbreak of acute gastroenteritis occurred in September 2006 in a boarding school in eastern Austria. Of 113 cases, 101 were hospitalised. In order to identify the outbreak source, a retrospective cohort study on the group at risk was performed, including 222 pupils and 30 staff members. Food exposure in the canteen of the school was identified as the most relevant common link among the cases in the case series investigation. Although the preliminary microbiological investigation made Norovirus infections possible, an in-depth descriptive epidemiological investigation later pointed to food intoxication rather than a viral infection as the cause of the outbreak. The analytical epidemiological investigation implicated boiled rice and chicken wings served in the canteen as the most likely source of the outbreak. Staphylococcus aureus was identified as the causative agent. Further molecular characterisation revealed that the predominant S. aureus type in this outbreak was a new spa type, t2046. The same spa type was isolated from stool specimens of the majority of the cases investigated, from samples of the incriminated boiled rice, and also from a swab of a palmar skin lesion of one of the healthy kitchen workers, who is therefore the most likely source of contamination. This outbreak underlines again the importance of compliance with the basic guidelines for kitchen hygiene.

An outbreak of gastroenteritis due to Salmonella Enteritidis phage type 4 occurred in people who attended a traditional hunting festivity in a small village in western Austria 6 through 11 November 2005. Of approximately 250 attendees, 227 had consumed dishes offered at the festival, and of these consumers 35 persons fulfilled the outbreak case definition (attack rate of 15.4%). Spätzle (traditional pastalike side dish) was most likely the contaminated part of the incriminated main course (relative risk of 18.9, 95% confidence interval of 4.6 to 76.7; P < 0.001). Thirteen eggs that remained from the preparation of the spätzle were negative for Salmonella when tested individually without shell disinfection, as were 1200 eggs collected at the egg production plant and examined with shell disinfection. The back-traced egg production farm had been initially certified as Salmonella free by a voluntary quality control program. However, an intensified environmental investigation of the incriminated egg production farm performed in the first quarter of 2006 and based on an appropriate method of sampling revealed Salmonella Enteritidis phage type 4 in 4 of 13 flocks. Although a combination of epidemiological and microbiological investigations allowed elucidation of the mode of spread, no restrictions were placed on the incriminated flocks of laying hens. These flocks were kept in production until they were stalled out due to age in August 2006. In June 2006, a cluster of 23 cases of Salmonella Enteritidis phage type 6 infection was again associated with this egg production farm. Evidence provided by epidemiological analyses is often disregarded by decision makers. However, negative results from microbiological testing of food involved in an outbreak are often weighted as strong evidence against a causal association between that food and the outbreak.

A cluster of 10 cases of tuberculosis disease (one of them extrapulmonary) occurred from July 2001 until November 2003 in a health district in Southern Austria. Eight patients were culture confirmed and shared an identical strain. One of these eight cases was identified as outbreak-related by molecular strain typing only. Due to public pressure, a further 600 persons received chest X-ray and clinical examinations. Apart from one case which could be excluded from the outbreak because of a different strain pattern, no outbreak-related case of active tuberculosis was detected by this non-targeted procedure. Tuberculin skin testing, not part of the Austrian routine protocol of contact investigation in adults, was initiated after diagnosis of case 8. Forty-nine latently infected contacts were detected. Population-based genotyping of all isolates, prioritization of contact investigations and early use of targeted tuberculin skin testing are critical for effective tuberculosis control in low-incidence countries.