Austria is officially bovine tuberculosis (TB) free, but during the last decade the west of the country experienced sporadic TB cases in cattle. Free-ranging red deer are known to be the maintenance ...host of
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in certain areas in Austria, where cattle can become infected on alpine pastures shared with deer. The epidemiology of TB in deer in alpine regions is still poorly understood. To inform decisions on efficient interventions against TB in deer, a method is needed to better capture the infection dynamics on population level. A total of 4,521 free-ranging red deer from Austria's most western Federal state Vorarlberg were TB-tested between 2009 and 2018.
was confirmed in samples from 257 animals. Based on descriptions of TB-like lesions, TB positive animals were categorized with a newly developed lesion score called "Patho Score." Analyses using this Patho Score allowed us to distinguish between endemic, epidemic and sporadic TB situations and revealed different roles of subgroups of infected deer in infection dynamics. Overall, deer in poor condition, deer of older age and stags were the subgroups that were significantly more often TB positive (
= 0.02 or smaller for all subgroups). Deer in poor condition (
< 0.001) and stags (
= 0.04) also showed more often advanced lesions, indicating their role in mycobacterial spread. TB was never detected in fawns, while hinds were the subgroup that showed the fewest advanced lesions. Analysis of outbreaks of TB and lesion development in yearlings provided some evidence for the role of winter feeding as a source for increased infection transmission. Sporadic cases in TB-free areas appear to precede outbreaks in these areas. These currently TB-free areas should receive particular attention in sampling schemes to be able to detect early spreading of the infection. The Patho Score is a quick, easy-to-apply and reproducible tool that provides new insights on the epidemiology of TB in deer at population level and is flexible enough to relate heterogeneous wildlife monitoring data collected following different sampling plans. This lesion score was used for systematic assessment of infection dynamics of mycobacterial infections.
Mycobacterium caprae subtype Lechtal was detected in a red fox (Vulpes vulpes) shot by a hunter in 2018 in the western part of Austria, where, among wildlife, tuberculosis is known to occur in red ...deer (Cervus elaphus). The red fox showed a generalized (disseminated) manifestation of the disease and a multibacillary distribution of mycobacteria in the inner organs.
Schmallenberg virus (SBV) has emerged in summer–autumn 2011 in north-western Europe. Since then, SBV has been continuously spreading over Europe, including Austria, where antibodies to SBV, as well ...as SBV genome, were first detected in autumn 2012. This study was performed to demonstrate the dynamics of SBV spread within Austria, after its probable first introduction in summer 2012. True seroprevalence estimates for cattle and small ruminates were calculated to demonstrate temporal and regional differences of infection. Furthermore, the probability of SBV genome detection in foetal tissues of aborted or stillborn cattle and small ruminants as well as in allantoic fluid samples from cows with early foetal losses was retrospectively assessed.
SBV first reached Austria most likely in July–August 2012, as indicated by retrospective detection of SBV antibodies and SBV genome in archived samples. From August to October 2012, a rapid increase in seroprevalence to over 98% in cattle and a contemporaneous peak in the detection of SBV genome in foetal tissues and allantoic fluid samples was noted, indicating widespread acute infections. Notably, foetal malformations were absent in RT-qPCR positive foetuses at this time of the epidemic. SBV spread within Austrian cattle reached a plateau phase as early as October 2012, without significant regional differences in SBV seroprevalence (98.4–100%). Estimated true seroprevalences among small ruminates were comparatively lower than in cattle and regionally different (58.3–95.6% in October 2012), potentially indicating an eastward spread of the infection, as well as different infection dynamics between cattle and small ruminants. Additionally, the probability of SBV genome detection over time differed significantly between small ruminant and cattle samples subjected to RT-qPCR testing.
A polycystic disease of the liver was diagnosed in 12 adult, free-living chamois (Rupicaprae rupicaprae) from alpine regions in the Western part of Austria. The animals (eight female, four male), all ...in advanced age (average 13 yr old), were killed by local hunters, most because of emaciation or abnormal behavior. The livers of the animals were enlarged and contained multiple, thin-walled cysts of various sizes filled with serous, amber fluid. No evidence for parasites was found in the cysts. There were no cysts present in other organs. The cysts were lined by a single layer of flattened or low, cubical epithelium indicating biliary origin. Except in one case, no fibrosis was found in the adjacent liver tissue. In six cases, mild eosinophilic inflammation in the surrounding hepatic parenchyma suggested that the cysts could result from previous parasitic migration. Although nothing is known regarding heredity, these morphologic findings may also indicate an adult type of polycystic disease. To our knowledge, this is the first report describing polycystic liver disease in this species.
Here, we report the results of a monitoring study of bat viruses in Austria to strengthen the knowledge of circulating viruses in Austrian bat populations. In this study, we analyzed 618 ...oropharyngeal and rectal swab samples from 309 bats and 155 pooled tissue samples from dead bats. Samples were collected from 18 different bat species from multiple locations in Austria, from November 2015 to April 2018, and examined for astroviruses, bornaviruses, coronaviruses, hantaviruses, morbilliviruses, orthomyxoviruses (influenza A/C/D viruses), pestiviruses and rhabdoviruses (lyssaviruses) using molecular techniques and sequencing. Using RT-qPCR, 36 samples revealed positive or suspicious results for astroviruses, Brno-hantaviruses, and coronaviruses in nine different bat species. Further sequencing revealed correspondent sequences in five samples. In contrast, none of the tested samples was positive for influenza viruses A/C/D, bornaviruses, morbilliviruses, lyssaviruses, or pestiviruses.
The emergence of West Nile virus (WNV) was expected in Austria since the initial discovery of the infection in neighbouring Hungary in 2003/2004. In 2008 six cases of West Nile disease were diagnosed ...at the Institute for Veterinary Disease Control Mödling, Austrian Agency for Health and Food Safety (AGES), involving five goshawks (Accipiter gentilis) and one gyrfalcon (Falco rusticolus), which were found dead in the eastern Austrian federal states of Lower Austria, Vienna and Styria, respectively. Pathomorphological and immunohistochemical findings suggested a WNV infection. Virus was isolated in embryonated specific pathogen free chicken eggs and propagated in mouse neuroblastoma cells (NA), in which a cytopathic effect occurred. The virus was identified and characterised by electron microscopic examination and molecular detection using RT-PCR, sequencing, and phylogenetic analysis. The Austrian WNV sequences exhibited nucleotide identities of 99.9% to the lineage 2 WNV sequences described in Hungary since 2004. In addition, 71 sera of 14 different bird species were screened for the presence of WNV antibodies using a commercial ELISA: 43.7% of the tested samples showed antibody titers. Selected positive sera were also subjected to WNV neutralisation tests, in which the ELISA results were verified in 66%. The results of this study confirm unambiguously the presence of a lineage 2 WNV infection in birds of prey in the eastern part of Austria.
Information on the population dynamics of a reservoir species have been increasingly adopted to understand and eventually predict the dispersal patterns of infectious diseases throughout an area. ...Although potentially relevant, to date there are no studies which have investigated the genetic structure of the red fox population in relation to infectious disease dynamics. Therefore, we genetically and spatially characterised the red fox population in the area stretching between the Eastern and Dinaric Alps, which has been affected by both distemper and rabies at different time intervals. Red foxes collected from north-eastern Italy, Austria, Slovenia and Croatia between 2006-2012, were studied using a set of 21 microsatellite markers. We confirmed a weak genetic differentiation within the fox population using Bayesian clustering analyses, and we were able to differentiate the fox population into geographically segregated groups. Our finding might be due to the presence of geographical barriers that have likely influenced the distribution of the fox population, limiting in turn gene flow and spread of infectious diseases. Focusing on the Italian red fox population, we observed interesting variations in the prevalence of both diseases among distinct fox clusters, with the previously identified Italy 1 and Italy 2 rabies as well as distemper viruses preferentially affecting different sub-groups identified in the study. Knowledge of the regional-scale population structure can improve understanding of the epidemiology and spread of diseases. Our study paves the way for an integrated approach for disease control coupling pathogen, host and environmental data to inform targeted control programs in the future.
As evidenced by sero-epidemiological studies, infections of horses with the tick-borne encephalitis virus (TBEV) occur frequently in TBEV-endemic areas. However, there are only very few reports of ...clinical cases. A possible underreporting may be due to a variety of diagnostic challenges. In this study, ELISA and neutralization tests were applied to serum samples. Brain tissue samples were investigated for the presence of nucleic acids of TBEV, Equid alphaherpesvirus 1, Borna disease virus 1, West Nile and Usutu viruses, rustrela virus, as well as Eastern, Western, and Venezuelan equine encephalitis viruses with RT-qPCR, RT-PCR, and qPCR, respectively. TBEV-specific amplification products were subjected to Sanger sequencing. In addition, a direct fluorescent antibody test for rabies was performed. Clinical and patho-histological findings are reported. Using specific RT-qPCR and RT-PCR assays, TBEV nucleic acids were demonstrated in brain tissue samples. Sequencing revealed the Western (formerly Central) European subtype of TBEV as the etiological agent. A high titer of TBEV-specific neutralizing antibodies was found in the serum. RNAscope in situ hybridization revealed TBEV RNA confined to neuronal cell bodies and processes. No other pathogens or nucleic acids thereof could be detected. Diagnostic procedures need to be carried out early after the onset of neurological signs to allow for a final etiological diagnosis of acute TBEV infections in horses.
A final diagnosis in a horse with clinical signs of encephalopathy can be challenging despite the use of extensive diagnostics. Clinical signs are often not pathognomonic and need to be interpreted ...in combination with (specific) laboratory results and epidemiological data of the geographical region of the origin of the case(s). Here we describe the diagnostic pathway of tick-borne encephalitis virus infection in two horses using established molecular diagnostic methods and a novel in situ hybridization technique to differentiate between regionally important/emerging diseases for central Europe: (i) hepatoencephalopathy, (ii) Borna disease virus, and (iii) West Nile virus infections.
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