Reproductive failure in an Austrian piglet-producing farm due to porcine circovirus genotype 2d.

Infections of pigs with porcine circovirus type 2 (PCV2) can lead to various clinical conditions including reproductive disorders (PCV2-RD). In general, a transplacental infection of fetuses leads to mummification and stillbirth. So far, PCV2-RD has mainly been described in specific-pathogen-free (SPF) herds or farms with a high proportion of gilts. From December 2018 to February 2019, a high abundance of mummified fetuses (15.5%) was observed in two farrowing groups in an Austrian piglet-producing farm. PCV2 DNA was detected using qPCR in organs of all six investigated fetuses (2.07 × 108-1.09 × 1012 PCV2) genome equivalents/g tissue and via in situ hybridisation in organs from five fetuses, while histologic lesions were not observed in a single fetal heart. All isolates were sequenced and identified as PCV2d. After the implementation of a regular vaccination of all sows against PCV2, the abundance of mummified fetuses dropped to 3.5% in May 2019. In contrast to previous reports about PCV2-RD, this farm was neither an SPF herd nor a start-up herd with a high proportion of gilts. The implementation of regular PCV2 vaccination helped to reduce the abundance of mummified fetuses substantially.

Porcine circovirus type 2 (PCV2) genotyping in Austrian pigs in the years 2002 to 2017.

BACKGROUND: Eight different PCV2 genotypes with varying prevalence and clinical impact have been described so far. PCV2 infection is still widespread among the vaccinated population and several experimental studies have clearly demonstrated that there is no induction of a 100% cross-protective immunity between the PCV2 genotypes. Hence, PCV2a-based vaccines may be ineffective. In this longitudinal study, the PCV2 genotype and haplotype evolution in Austria in the years 2002 to 2017 was investigated by phylogenetic analysis of 462 bp-long sequences of the capsid protein gene (ORF2). The obtained findings may be of practical relevance for the future development of vaccination strategies. RESULTS: One hundred thirty four of a total of 161 formalin-fixed and paraffin wax-embedded samples could be sequenced successfully. There was no significant influence of storage time on sequencing success or quality. PCV2a (8.2%), PCV2b (77.6%), PCV2d (13.4%), and PCV2g (0.8%) were found. PCV2d was first detected as early as in 2004. PCV2g was described once in 2009. Both global PCV2 genotype shifts were observed. PCV2a occurred with a low prevalence during the first study years only in samples from non-vaccinated swine herds and was gradually replaced by PCV2b until 2011. PCV2b was the most prevalent genotype over the whole study period and was detected in samples from vaccinated and non-vaccinated herds. During the last two study years, the prevalence of PCV2d increased, although at this point almost all herds were vaccinated. The haplotype diversity was high, but the nucleotide diversity was low. Especially for genotype PCV2b, an increase in haplotype diversity could be described during the first study years. CONCLUSION: Extensive PCV2a-derived vaccination resulted in a reduction of prevalence and in a stabilization of genotype PCV2a, whereas genotypes PCV2b and PCV2d evolved as a consequence of natural and vaccination-induced selection. An ongoing virus circulation may be the result of reduced vaccine-induced protection.

Listeriosis in fattening pigs caused by poor quality silage - a case report.

BACKGROUND: Listeria (L.) monocytogenes as the causative agent of listeriosis in humans and different animal species, has its reservoir in the environment. It can be found in the gut and faeces of healthy pigs, but under certain circumstances it may cause clinical disease. Fatteners are usually not known to get affected by Listeria-associated septicaemia and enteritis. This case report shows, that L. monocytogenes should be part of the list of differential diagnoses, when fattening pigs suffer from haemorrhagic diarrhoea and septicaemia. CASE PRESENTATION: Here, we report of an episode of fatal listeriosis in fattening pigs in a piglet producing farm in Lower Austria, which was combined with a fattening unit with space for 450 fatteners. The mortality rate resulted in 7.8% among fattening pigs after suffering from clinical symptoms such as anorexia, bloody diarrhoea and increased body temperature. Two fattening pigs with clinical symptoms and maize silage samples were used for further diagnostics. L. monocytogenes were isolated from serosa samples of the pigs and in the corresponding fed maize silage. One animal was positively tested for Brachyspira hyodysenteriae, which may have also been involved in the development of colitis. Immunohistochemically, L. monocytogenes could be detected in high amounts in lymphatic tissue of the gut. Molecular biological characterisation of the L. monocytogenes isolates from pigs and maize silage resulted in an identical DNA-fingerprint assigned to sequence type (ST) 21. Additionally, a high content of deoxynivalenol (3000 parts per billion) was found in maize silage. Therefore, the maize silage produced under inappropriate ensilaging conditions in a silo, was most likely the source of infection. Antimicrobial therapy with amoxicillin led to a fast cure of the remaining affected fatteners. CONCLUSION: To conclude, we were able to show, that L. monocytogenes can cause clinical disease in finishing pigs, which may have been a result of immunosuppression due to high deoxynivalenol exposure. When feeding silage it is important that all ensilaging procedures occur under appropriate anaerobic conditions to guarantee suppression of listerial growth.

Successful treatment of pemphigus foliaceus in a Berrichon du Cher ram with methylprednisolone acetate.

BACKGROUND: Pemphigus foliaceus is a severe, autoimmune blistering skin disease, which is described in humans and some animal species. In small ruminants pemphigus foliaceus has rarely been described and, to the best of the authors' knowledge, little information is available about successful treatment in sheep. AIM: This case report describes a Berrichon du Cher ram with the presumed diagnosis of pemphigus foliaceus. METHODS: The ram was treated with methylprednisolone acetate 40 mg at a dosage of 2.5 mg/kg in one subcuticular injection at four week intervals over a one year period, with regular observation of clinical parameters. Four months after treatment was initiated the haematological parameters showed lymphopenia and leukopenia; some enzyme activities were substantially increased. RESULTS: The ram's dermatological condition improved to the point of complete healing of the affected skin. The ram was discharged in good condition. No adverse effects, except an elevation of some enzymes associated with liver function, were observed. At postmortem examination moderate fatty liver syndrome was the only abnormality found. CONCLUSIONS AND CLINICAL IMPORTANCE: This case report demonstrated that long term therapy with methylprednisolone acetate in a sheep with pemphigus foliaceus did not have a negative effect on clinical parameters. Nevertheless, due to the extended statutory withdrawal period resulting from the regular administration of glucocorticoids, such a therapeutic option must be critically assessed in food producing animals.

Genetic loci of Mycoplasma agalactiae involved in systemic spreading during experimental intramammary infection of sheep.

Mycoplasmas are amongst the most successful pathogens of both humans and animals yet the molecular basis of mycoplasma pathogenesis is poorly understood. This is partly due to the lack of classical virulence factors and little similarity to common bacterial pathogenic determinants. Using Mycoplasma agalactiae as a model we initiated research in this direction by screening a transposon mutant library in the natural sheep host using a negative selection method. Having successfully identified putative factors involved in the colonization of local infection and lymphogenic sites, the current study assessed mutants unable to spread systemically in sheep after experimental intramammary infection. Analysis of distant body sites for complete absence of mutants via SSM PCR revealed that additional set of genes, such as pdhB, oppC, oppB, gtsB, MAG1890, MAG5520 and MAG3650 are required for systemic spreading apart from those that were necessary for initial colonization. Additional in vitro studies with the mutants absent at these systemic sites confirmed the potential role of some of the respective gene products concerning their interaction with host cells. Mutants of pdhB, oppC and MAG4460 exhibited significantly slower growth in the presence of HeLa cells in MEM medium. This first attempt to identify genes exclusively required for systemic spreading provides a basis for further in-depth research to understand the exact mechanism of chronicity and persistence of M. agalactiae.

In vitro and in vivo cell invasion and systemic spreading of Mycoplasma agalactiae in the sheep infection model.

Generally regarded as extracellular pathogens, molecular mechanisms of mycoplasma persistence, chronicity and disease spread are largely unknown. Mycoplasma agalactiae, an economically important pathogen of small ruminants, causes chronic infections that are difficult to eradicate. Animals continue to shed the agent for several months and even years after the initial infection, in spite of long antibiotic treatment. However, little is known about the strategies that M. agalactiae employs to survive and spread within an immunocompetent host to cause chronic disease. Here, we demonstrate for the first time its ability to invade cultured human (HeLa) and ruminant (BEND and BLF) host cells. Presence of intracellular mycoplasmas is clearly substantiated using differential immunofluorescence technique and quantitative gentamicin invasion assays. Internalized M. agalactiae could survive and exit the cells in a viable state to repopulate the extracellular environment after complete removal of extracellular bacteria with gentamicin. Furthermore, an experimental sheep intramammary infection was carried out to evaluate its systemic spread to organs and host niches distant from the site of initial infection. Positive results obtained via PCR, culture and immunohistochemistry, especially the latter depicting the presence of M. agalactiae in the cytoplasm of mammary duct epithelium and macrophages, clearly provide the first formal proof of M. agalactiae's capability to translocate across the mammary epithelium and systemically disseminate to distant inner organs. Altogether, the findings of these in vitro and in vivo studies indicate that M. agalactiae is capable of entering host cells and this might be the strategy that it employs at a population level to ward off the host immune response and antibiotic action, and to disseminate to new and safer niches to later egress and once again proliferate upon the return of favorable conditions to cause persistent chronic infections.

Demodicosis in a Kunekune pig and molecular characterisation of porcine demodectic mites involved: a case report.

BACKGROUND: In January 2021, a female 1-year-old Kunekune was presented at the University Clinic for Swine with severe reduction of the field of vision resulting in prolonged reaction time when targeting barriers, due to moderate to severe thickening of the skin around both orbits also affecting the eyelids. METHODS: Clinical examination revealed skin hyperplasia, nodular enlargement of the skin pores of the axillar and inguinal region. Ophthalmologists decided to remove parts of the thickened periocular skin, followed by histopathological examination. RESULTS: Once large amounts of demodectic mites were detected by histopathology, demodicosis could be diagnosed and treatment of the pig was started using sarolaner. Morphological and molecular analyses were performed. Histopathological and parasitological exams led to the aetiological diagnosis of demodicosis in the affected Kunekune pig. Severe skin lesions were revealed to be the consequence of an infestation with Demodex sp. Morphological analyses confirmed the involvement of D. phylloides. Molecular characterization indicated a Demodex species closely related to mites documented in wild boar - most probably D. phylloides for which no explicit sequences are available in GenBank yet. Treatment with sarolaner (2.6 mg/kg) resulted in a substantial regression of skin lesions, already detectable 1 month after first treatment. CONCLUSIONS: Demodicosis is a very rare disease in pigs that is most probably related to an impaired immune response to the mites. Demodectic mange should be included in the list of differential diagnoses in cases of periocular alterations of the skin of pigs.

Suspected goat-to-human transmission of methicillin-resistant Staphylococcus aureus sequence type 398.

Transmission of methicillin-resistant Staphylococcus aureus (MRSA) between animals and humans is widely recognized. In this study, we describe the first case of infection of a goat and suspected transmission of MRSA ST398 to a human, which resulted in colonization of animal owners by MRSA sequence type 398.

A single, episodic event of unilateral/bilateral scrotal swelling in a group of adult boars at an Austrian boar stud.

BACKGROUND: Scrotal swelling is a clinical situation which can be caused by different aetiologies. In this case report, we describe a multi-week episode of unilateral and bilateral scrotal swelling in boars at an Austrian boar stud and its diagnostic work-up. CASE PRESENTATION: In the summer of 2020, the herd veterinarian of an Austrian boar stud reported that over a period of six weeks, five out of 70 boars presented with unilateral severe swelling of the left scrotum and three out of 70 boars with bilateral severe swelling of the left and moderate swelling of the right scrotum, respectively. A complete history was obtained and an on-site evaluation of the facility was done. Five boars were necropsied, and a variety of samples harvested for further diagnostic investigations. Infectious differential diagnoses associated with unilateral swelling of the scrotum or the testis were excluded through serological and tissue testing. In three of the five boars, histopathology revealed complete acute haemorrhagic necrosis of the left testis concurrent with strongly congested blood vessels. Review of the collected information with a group of experts in the field of boar stud management resulted with consensus that, most likely, trauma was the etiologic event causing the clinical signs and pathology. Coincident with discussion of implementing video recording cameras in the boar housing area, no further clinical cases followed. As this case occurred during the first lockdown of the COVID-19 pandemic, we propose that the distress and travelling restrictions may have contributed to frustration among boar stud workers, which was consequently expressed as misbehaviour against boars. CONCLUSIONS: Once all known infectious causes of unilateral swelling of the scrotum were excluded, a critical diagnostic work-up focused on non-infectious causes. Non-infectious causes, such as trauma, need to be carefully evaluated, as it may also include human misbehaviour against boars. Summarizing all findings of this case report, the authors hypothesize that a blunt trauma was the reason for the series of mainly unilateral swelling of the scrota of boars.

[Severe chronic osteomyelitis of the os ileum in an alpaca - Diagnostic and pathological findings]. / Hochgradige chronische Osteomyelitis des Darmbeines bei einem Alpaka.

A 5.5-year-old alpaca mare was referred to the University Clinic for Ruminants due to a lameness in the right hind limb. Six months prior to presentation, the mare had been treated with systemic antibiotics resulting in resolution of the initial lameness. At the time there had been no indication of an inciting trauma. Clinical examination revealed an approx. 2 × 2 cm large, fluctuating, neither excessively warm nor painful mass caudal to the right tuber coxae fixed to the underlying tissue. In addition, a moderate, mixed lameness with a predominant proportion of the swinging leg component was present in the right hind limb. Subsequently, sonographic examination of the right gluteal region was performed, revealing severe alterations of bone contour in the area of the right hip joint. Radiographic assessment of the pelvis was carried out for further clarification. Based on the clinical finding of a fistula in the right gluteal region as well as the results of the radiologic examination, a long-standing infected fracture of the right iliac bone accompanied by high-degree, irregularly calcified callus formation and low to moderate osteomyelitis in the fracture area was diagnosed. The patient was euthanized in consequence of the grave prognosis. Computed tomographic examination of the pelvis and the lumbar spine in the L3-L6 area was undertaken in order to further document the extent of the pathological changes. For final clarification, patho-histological examination as well as a microbiologic analysis of the abscess exudate were performed.The presented case shows the importance of clinical as well as orthopedic examinations, as the individual animal frequently only exhibits minimal clinical signs despite the presence of severe changes.

Cystic endometrial hyperplasia and uterine adenocarcinoma in two miniature pigs.

Due to the increasing popularity of minipigs as pets, the frequency of presentation to the veterinarian is increasing as well. In addition to routine measures such as claw trimming, vaccination and antiparasitic treatment, diagnostics, and therapy of diseased minipigs are also common activities in the veterinary practice. In recent years, we have noticed more and more pathological changes of the female genital tract of uncastrated minipigs. There are also some case reports available in the international literature in this regard. The following case report describes the diagnostic procedures and ovariohysterectomies of 2 13-year-old female minipigs in detail. In these cases, uterine adenocarcinoma, and uterine carcinoma, respectively, combined with cystic endometrial hyperplasia (CEH) of the endometrium were diagnosed.

Trichomonosis in Austrian Songbirds-Geographic Distribution, Pathological Lesions and Genetic Characterization over Nine Years.

In the early summer of 2012, sudden mass mortality among songbirds, particularly in greenfinches (Chloris chloris, syn: Carduelis chloris) was observed in Austria, which was caused by the protozoan parasite Trichomonas gallinae. This pathogen induced fibrinonecrotic ingluvitis and/or esophagitis, leading to impairment of food intake and ultimately death due to starvation. The pathogen was successfully detected within the lesions by polymerase chain reaction (PCR) and chromogenic in situ hybridization. The epizootic resulted in a significant decline in the Austrian greenfinch population. Continuing passive surveillance in the subsequent years (2013-2020) revealed that the condition occurred each year and was present in the entire country. Genetic characterization of the pathogen showed the presence of an identical strain irrespective of geographical location, bird species, and year.

Strongyloides stercoralis infection in dogs in Austria: two case reports.

BACKGROUND: Strongyloides stercoralis is endemic in tropical and subtropical regions, but reports of infections in central and northern Europe have been recently increasing. Infections occur mainly in humans and dogs. In dogs, both dog-adapted and zoonotic S. stercoralis genotypes seem to occur. Clinical manifestations mainly include gastrointestinal and respiratory signs. The severity of the disease can vary greatly and depends on the immune status of the host. The infection is potentially fatal in immunosuppressed individuals, either medically induced or due to an underlying disease, in which hyperinfections and disseminated infections with extraintestinal parasite dissemination may occur. METHODS: Diagnosis was based on coproscopy, including flotation and the Baermann funnel technique, histology of small intestinal biopsies and molecular analysis of mitochondrial cytochrome oxidase subunit I (COI) and hypervariable regions I and IV (HVR I and HVR IV) of the nuclear 18S rDNA loci. RESULTS: Two independent cases of severe canine S. stercoralis infection in Austria are presented. In both cases, S. stercoralis was detected in histological sections of the small intestine and with the Baermann funnel technique. Molecular analysis revealed strains with zoonotic potential. Case 1 was a 1-year-old female French bulldog with a long history of respiratory and gastrointestinal signs, severe emaciation and apathy before S. stercoralis infection was diagnosed. Treatment with moxidectin (2.5 mg/kg body weight [BW], oral route) did not eliminate the infection, but treatment with ivermectin (0.2 mg/kg BW, subcutaneously) was successful. Case 2 consisted of two 2-month-old Pomeranian puppies, one female and one male, from a litter of four, which died soon after presenting dyspnoea and haemorrhagic diarrhoea (female) or torticollis (male); S. stercoralis infection was first diagnosed post-mortem. CONCLUSION: More attention should be paid to this nematode because although it appears to be rare in Austria, it is easily overlooked on standard coproscopy unless a Baermann funnel technique is used, and even then, it can be missed. Moxidectin is not always successful in eliminating the infection, and treatment with ivermectin should be considered in cases of infection.

Sheep Infection Trials with 'Phase-Locked' Vpma Expression Variants of Mycoplasma agalactiae-Towards Elucidating the Role of a Multigene Family Encoding Variable Surface Lipoproteins in Infection and Disease.

The significance of large multigene families causing high-frequency surface variations in mycoplasmas is not well-understood. Previously, VpmaY and VpmaU clonal variants of the Vpma family of lipoproteins of M. agalactiae were compared via experimental sheep infections using the two corresponding 'Phase-Locked Mutants'. However, nothing is known about the infectivity of the remaining four Vpma expression variants VpmaX, VpmaW, VpmaZ and VpmaV as they were never evaluated in vivo. Here, in vivo infection and disease progression of all six Vpma expressers constituting the Vpma family of type strain PG2 were compared using the corresponding xer1-disrupted PLMs expressing single well-characterized Vpmas. Each of the six PLMs were separately evaluated using the intramammary sheep infection model along with the control phase-variable wildtype strain PG2. Thorough bacteriological, pathological and clinical examinations were performed, including assessment of milk quality, quantity and somatic cell counts. Altogether, the results indicated that the inability to vary the Vpma expression phase does not hamper the initiation of infection leading to mastitis for all six PLMs, except for PLMU, which showed a defect in host colonization and multiplication for the first 24 h p.i. and pathological/bacteriological analysis indicated a higher potential for systemic spread for PLMV and PLMX. This is the first study in which all isogenic expression variants of a large mycoplasma multigene family are tested in the natural host.

Trichurosis on a Conventional Swine Fattening Farm with Extensive Husbandry-A Case Report.

Helminth infections of swine regain clinical and economic importance due to the increasing demand for pork from extensive husbandry. Infections with Trichuris suis in pigs can lead to wasting and diarrhoea. This was demonstrated by a case of clinical trichurosis on a conventional fattening farm, where pigs were kept on pasture. While all pre-fattening pigs, which had not been on the pasture yet, had a good body condition and firm faeces, diarrhoea and poor body condition were observed in approximately half of the fattening pigs kept on pasture. Rectally collected faecal samples from all animals were investigated using faecal flotation. High numbers of T. suis eggs were detected in 17 out of 32 faecal samples, while all samples from pre-fattening pigs were negative. The highest number of eggs per gram of faeces was 778,000. Two out of three environmental samples were also positive for T. suis in faecal flotation. This case demonstrates that T. suis must be considered as an enteropathogen in pigs kept on pasture, as favourable environmental conditions, and the lack of removal of faeces from a pasture can lead to the accumulation of large numbers of infective eggs in the pigs' surroundings.

New Emergence of the Novel Pestivirus Linda Virus in a Pig Farm in Carinthia, Austria.

Linda virus (LindaV) was first identified in a pig farm in Styria, Austria in 2015 and associated with congenital tremor (CT) type A-II in newborn piglets. Since then, only one more LindaV affected farm was retrospectively discovered 10 km away from the initially affected farm. Here, we report the recent outbreak of a novel LindaV strain in a farrow-to-finish farm in the federal state Carinthia, Austria. No connection between this farm and the previously affected farms could be discovered. The outbreak was characterized by severe CT cases in several litters and high preweaning mortality. A herd visit two months after the onset of clinical symptoms followed by a diagnostic workup revealed the presence of several viremic six-week-old nursery pigs. These animals shed large amounts of virus via feces and saliva, implying an important epidemiological role for within- and between-herd virus transmission. The novel LindaV strain was isolated and genetically characterized. The findings underline a low prevalence of LindaV in the Austrian pig population and highlight the threat when introduced into a pig herd. Furthermore, the results urge the need to better understand the routes of persistence and transmission of this enigmatic pestivirus in the pig population.

MULTIPLE EPIDEMICS IN AUSTRIAN FRINGILLIDAE CAUSED BY A SINGLE VARIANT OF SALMONELLA TYPHIMURIUM.

In Austria, numerous deaths of wild birds of the order Passeriformes, family Fringillidae, occurred during the winter months of 2010 and 2012. The Eurasian Siskin (Carduelis spinus) was the species most often affected. The dead birds were mainly found in the immediate vicinity of feeding places. Vigilant citizens sent birds (n=34) for pathologic examination to the Institute of Pathology in Vienna, Austria. All birds were cachectic or in a very poor nutritional condition. At gross examination, the most striking findings were multifocal to confluent, yellow-white nodules in the crop or esophageal mucosa. In histologically examined birds (n=24), severe transmural fibrino-purulent to necrotizing ingluviitis or esophagitis with large amounts of intralesional bacteria was observed. Bacteriologic examination of crop, liver, or other organs from 14 birds revealed abundant growth of Salmonella serovar Typhimurium (antigenic formula 1,4,5,12:i:1,2; phage type U277) in all individuals. By means of immunohistochemistry, these bacteria were detected not only in crop mucosa but also in lung tissue. In 17 birds (71%), structures morphologically resembling Macrorhabdus ornithogaster were detected histologically on the surface of the proventricular epithelium. Thus, the cause of mass mortality of the passerine birds was identified as infection with Salmonella Typhimurium, which was associated with growth of presumed M. ornithogaster in many cases.

Exudative Epidermitis in Combination with Staphylococcal Pyoderma in Suckling Piglets.

A case of generalized exudative epidermitis (EE) is described, which occurred in a very small piglet producing farm in Austria. The antimicrobial treatment prescribed by the herd veterinarian did not improve the clinical problem. Therefore, the University Clinic for Swine intervened in the case. Lab investigations were initiated in which Staphylococcus hyicus (SH) and Staphylococcus aureus (SA), both methicillin-resistant and susceptible strains, could be isolated from the skin of affected piglets. Poor hygiene and management practices were identified as predisposing factors on site. Adaptation of antimicrobial treatment according to results of the in vitro susceptibility testing and the implementation of proper hygiene measures resolved the clinical problem. Here, we describe a fatal coinfection of SH and SA in suckling piglets.

Investigations on the occurrence of a muscular disorder in Austrian slaughter pigs.

BACKGROUND: In slaughterhouse, veterinarians responsible for meat inspection are often confronted with abnormalities in carcasses, not only in pigs but in all livestock species. In 2017, a veterinarian responsible for meat inspection in a slaughterhouse in Styria, Austria, observed gluteal muscles infiltrated by fat and muscle tissue obviously being replaced by fat in two different slaughter pigs. These muscles were sent for further diagnostics to the University Clinic for Swine. RESULTS: The two muscle samples were investigated histopathologically and diagnosed with fatty muscular dystrophy. The results of routine histopathology were confirmed by dystrophin-specific immunohistochemistry. Sex of the two affected animals was determined retrospectively using a PCR-based protocol and resulted in one male and one female pig. A survey to determine the prevalence of fatty muscular disorders of pork revealed that this phenomenon gets frequently observed in Styria, but also occurs in Upper Austria and Lower Austria. Mostly gluteal and lumbal muscles were affected and approximately 20-40% of the affected muscles were replaced by fat. CONCLUSIONS: Fatty muscular dystrophy or muscular steatosis, as it was sometimes called in early literature, seems not to be an uncommon and rare event and is known to have several different causes. As it was detected in both sexes, our observations are different to the described case in Japan, where only one male individual was affected. To avoid further increase of such cases (fatty muscular dystrophy), it would be useful to clarify the cause. First, whether the cause is environmental or genetic, and in case it is genetic it would be key to disentangle the underlying genomic architecture. Having causal variants described-one could think about integrating this information (depending on the mode of inheritance and the number of loci involved) in the breeding program of pigs. Furthermore, the proportion of non-Austrian pig genetics used for commercial pig production in Austria should be reviewed in order to be able to make reliable statements about the spread of the disease not only in Austrian pig breeds, but also in pig breeds worldwide.

Different dynamics of Usutu virus infections in Austria and Hungary, 2017-2018.

Usutu virus (USUV), a mosquito-borne flavivirus closely related to West Nile virus, emerged in Austria in 2001, when it caused a considerable mass-mortality of Eurasian blackbirds. Cases in birds increased until 2003 and quickly declined thereafter, presumably due to developing herd immunity. Since 2006, no further cases were recorded, until two blackbirds were tested positive in 2016. In Hungary, USUV first appeared in 2005 and has caused only sporadic infections since then. Initially, the only genetic USUV lineage found across both countries was Europe 1. This changed in 2015/2016, when Europe 2 emerged, which has since then become the prevalent lineage. Due to dispersal of these strains and introduction of new genetic lineages, USUV infections are now widespread across Europe. In 2009, the first cases of USUV-related encephalitis were described in humans, and the virus has been frequently detected in blood donations since 2016. To monitor USUV infections among the Austrian wild bird population in 2017/2018, 86 samples were investigated by RT-PCR. In 67 of them, USUV nucleic acid was detected (17 in 2017, 50 in 2018). The majority of succumbed birds were blackbirds, found in Vienna and Lower Austria. However, the virus also spread westwards to Upper Austria and southwards to Styria and Carinthia. In Hungary, 253 wild birds were examined, but only six of them were infected with USUV (five in 2017, one in 2018). Thus, in contrast to the considerable increase in USUV-associated bird mortality in Austria, the number of infections in Hungary declined after a peak in 2016. Except for one case of USUV lineage Africa 3 in Austria in 2017, Europe 2 remains the most prevalent genetic lineage in both countries. Since USUV transmission largely depends on temperature, which affects vector populations, climate change may cause more frequent USUV outbreaks in the future.