Clinical Presentation and Laboratory Diagnostic Work-Up of a Horse with Tick-Borne Encephalitis in Switzerland

Tick-borne encephalitis is an important viral tick-borne zoonosis in Europe and Asia. The disease is induced by tick-borne encephalitis virus (TBEV). This report describes a 16-year-old Warmblood gelding presenting with sudden onset of lethargy, ataxia, and muscle fasciculations on the nostrils, the lips, and the eye lids as the most important clinical findings. The horse further had a mild facial nerve paralysis with drooping of the right upper and lower lip. Diagnosis was based on paired serum samples using TBEV-ELISAs revealing high serum IgM in the first sample with normal IgM in the second sample and an increase in serum IgG and neutralizing antibodies, indicating acute and recent infection. TBEV was confirmed by a virus-neutralization test, revealing a fivefold increase in antibodies 32 days after of the onset of clinical signs. Although the specific PCR on cerebrospinal fluid (CSF) was negative, TBEV-specific IgG and IgM were identified in the CSF of the horse. Treatment consisted of anti-inflammatory and anti-oxidative treatment and the horse recovered with a mild drooping of the right nostril as the only remaining clinical sign. TBEV infection is a potential differential diagnosis of neurological disease in horses living in endemic areas and this is the first report to describe the diagnostic criteria in a horse as recommended in humans with suspected TBEV infection

Different Outcomes of Experimental Hepatitis E Virus Infection in Diverse Mouse Strains, Wistar Rats, and Rabbits

Hepatitis E virus (HEV) is the causative agent of acute hepatitis E in humans in developing countries, but autochthonous cases of zoonotic genotype 3 (HEV-3) infection also occur in industrialized countries. In contrast to swine, rats, and rabbits, natural HEV infections in mice have not yet been demonstrated. The pig represents a well-established large animal model for HEV-3 infection, but a suitable small animal model mimicking natural HEV-3 infection is currently missing. Therefore, we experimentally inoculated C57BL/6 mice (wild-type, IFNAR−/−, CD4−/−, CD8−/−) and BALB/c nude (nu/nu) mice, Wistar rats, and European rabbits with a wild boar-derived HEV-3 strain and monitored virus replication and shedding, as well as humoral immune responses. HEV RNA and anti-HEV antibodies were detected in one and two out of eight of the rats and all rabbits inoculated, respectively, but not in any of the mouse strains tested. Remarkably, immunosuppressive dexamethasone treatment of rats did not enhance their susceptibility to HEV infection. In rabbits, immunization with recombinant HEV-3 and ratHEV capsid proteins induced protection against HEV-3 challenge. In conclusion, the rabbit model for HEV-3 infection may serve as a suitable alternative to the non-human primate and swine models, and as an appropriate basis for vaccine evaluation studies

West Nile Virus in Germany: An Emerging Infection and Its Relevance for Transfusion Safety

West Nile virus (WNV) is an arthropod-borne virus (arbovirus). It circulates in an enzootic cycle between ornithophilic mosquitoes as vectors and reservoirs and avian host species for amplification, but humans can be infected as accidental hosts. In most individuals, WNV infection remains silent, while 20% develop mild symptoms of West Nile fever, and only 1% develop neuroinvasive disease (WNND). Human WNV cases have been identified in Southern and Eastern Europe for more than 20 years, but until 2018, Germany was considered to be a non-endemic country. This changed when in the exceptionally warm summer of 2018, conditions for viral replication in mosquitoes were ideal, and the first WNV cases among birds and horses were identified. The widespread domestic Culex mosquitoes are efficient vectors for WNV. Autochthonous mosquito-borne WNV infections in humans were reported in all following years, indicating a continuous circulation in the affected areas of Central-East Germany. So far, no clear expansion of the affected areas is discernible but may develop. WNV is a transfusion-transmissible-infection, and donor deferral or testing of donations after a stay in an affected area are effective means to ensure transfusion safety. WNV transmissions via blood products often result in WNND due to the predisposing underlying medical conditions of transfusion recipients. From 2020 onwards, roughly 80% of all blood establishments in Germany tested their donations for WNV using nucleic acid amplification techniques in the transmission season. Altogether, 19 confirmed WNV infections were identified from 2020–2021. As long as effective and affordable pathogen reduction is not available for all blood components, WNV testing or donor deferral will be essential. In order to timely identify affected areas, combined results of human and veterinary surveillance are needed. Partnerships between public health experts, transfusion medicine specialists, veterinarians, and entomologists should be strengthened to ensure a One Health approachPeer Reviewe

Detection and molecular analysis of Hop latent virus and Hop latent viroid in hop samples from Poland

Die Überwachung von Viruskrankheiten bei Pflanzen ist wichtig für die Durchführung frühzeitiger Kontrollmaßnahmen und die Verhinderung der weiteren Ausbreitung der Erreger. In Polen wurde im Jahr 2004 ein Programm zur Eliminierung von Viren und Viroiden im Hopfen gestartet. In den Jahren 2012/13 wurden in vitro Pflanzen, Proben aus der IUNG-PIB Versuchsstation und aus kommerziellen polnischen Hopfengärten auf das Hop latent virus, Hop latent viroid und Hop stunt viroid getestet. Für die Virus­testung wurden RT-PCR und ELISA eingesetzt. Die Viroide wurden mittels RT-PCR nachgewiesen. Insgesamt war die Nachweishäufigkeit für Viren und Viroide geringer als vor dem Start des Programms. Klonierung und Sequenzierung lassen den Schluss zu, dass das Hop latent virus und das Hop latent viroid aus den polnischen Proben den „type“ Sequenzen und den tschechischen Viren/Viroiden sehr ähnlich sind. DOI: 10.5073/JfK.2014.07.04, https://doi.org/10.5073/JfK.2014.07.04Monitoring the occurrence of virus diseases in plants is important for the implementation of early control measures and prevention of further disease spread. In Poland, in 2004 a health programme for hop was started to eliminate viruses and viroids. In 2012/13, in vitro plants, samples from the IUNG-PIB experimental station and commercial hop gardens in Poland were tested for Hop latent virus (HpLV), and Hop latent and Hop stunt viroids (HpLVd and HpSVd). For virus testing, RT-PCR and ELISA methods were used. In order to detect hop viroids, RT-PCR was employed. The overall incidence of HpLV and hop viroids was lower than reported before the start of the programme. Cloning and sequencing revealed that the HpLV and the HpLVd from Polish sources are very similar to the type sequences and the Czech sources. DOI: 10.5073/JfK.2014.07.04, https://doi.org/10.5073/JfK.2014.07.0

Occurrence of Soil-borne wheat mosaic virus (SBWMV-NY) in Schleswig-Holstein and its importance for wheat cultivation

Erhebungen zum Vorkommen bodenbürtiger Viren in Schleswig-Holstein zeigten, dass in diesem Bundesland das Soil-borne wheat mosaic virus (SBWMV) in Weizen- und Roggenanbaugebieten verbreitet ist. Während in Süddeutschland der Nebraska (N)-Stamm dieses Virus vorkommt, tritt in Norddeutschland der New York (NY)-Stamm auf. In den Infektionsherden der Getreidefelder werden verschiedene Winterweizensorten stark geschädigt. Um Anbauempfehlungen für die Kultivierung virusresistenten Weizens in Befallsregionen geben zu können, wurden ausgewählte Sorten unter Gewächshausbedingungen in infektiöser Erde eines betroffenen Standortes auf Resistenz getestet. Weiterhin erfolgte die Identifizierung des diagnostischen Markers Xgwm469-5D (153 bp- oder 155 bp-Allel) für das Sbm1-Resistenzgen gegen Furo­viren im geprüften Weizenmaterial. Im Ergebnis dieser Untersuchungen können für den Weizenanbau in mit SBWMV-NY verseuchten Flächen die Sorten Farandole, Hyland, Hybery, Mirage und Carenius empfohlen werden.    The study of soil-borne viruses in Schleswig-Holstein shows an increasing distribution of Soil-borne wheat mosaic virus (SBWMV) in wheat and rye growing areas in this federal state of Germany. Whereas the Nebraska (N) strain of this virus was found in Southern Germany, the New York (NY) strain is present in Northern Germany. Selective wheat cultivars were screened for resistance to this virus under greenhouse conditions in an infested soil sample with the aim to develop recommendations for growers. Furthermore, the identification of the diagnostic marker Xgwm469-5D (153 bp- or 155 bp-allel) for the Sbm1-resistance gene against furoviruses was carried out in the wheat material under investigation. As a result of our work, the cultivation of the wheat cultivars Farandole, Hyland, Hybery, Mirage and Carenius is recommended for SBWMV-NY affected fields.   &nbsp

West Nile virus antibody prevalence in horses of Ukraine

West Nile virus (WNV) is a mosquito-borne virus of global importance. Over the last two decades, it has been responsible for significant numbers of cases of illness in humans and animals in many parts of the world. In Ukraine, WNV infections in humans and birds were first reported more than 25 years ago, yet the current epidemiological status is quite unclear. In this study, serum samples from over 300 equines were collected and screened in order to detect current WNV activity in Ukraine with the goal to estimate the risk of infection for humans and horses. Sera were tested by enzyme-linked immunosorbent assay (ELISA) and virus neutralization assay (NT) to detect WNV- specific antibodies. The results clearly revealed that WNV circulates in most of the regions from which samples were obtained, shown by a WNV seroprevalence rate of 13.5% of examined horses. This is the first topical report indicating the presence of WNV infections in horses in Ukraine, and the results of this study provide evidence of a widespread WNV circulation in this country

Neurological disease suspected to be caused by tick‐borne encephalitis virus infection in 6 horses in Switzerland

Background Reports on acute tick-borne encephalitis virus (TBEV) infections with signs of neurologic disease in horses are limited. Objectives To describe the epidemiological, clinical, and laboratory findings of suspected acute TBEV infections in 6 horses. Animals Six horses originating from TBEV endemic regions of Switzerland were presented to equine hospitals with acute onset of neurologic disease between 2011 and 2019. Methods Retrospective case series. Horses with acute onset of signs of neurologic disease that were subjected to clinical and microbiological examinations to rule out infectious diseases affecting the central nervous system. Results All horses exhibited acute signs of neurologic disease including ataxia and proprioceptive deficits. Horses tested positive for TBEV using virus neutralization test and samples were further tested for TBEV-specific IgM. The presence of TBEV-specific IgM antibodies was confirmed in 5 horses (cases 1-5, Laboratory Unit [LU] values ranging from 30 to 56). One horse (case no. 6) with an LU value just below the test threshold (LU = 22.3) was also included under the hypothesis that the horse was transitioning from acute to chronic infection. All horses originated from areas where humans with confirmed tick-borne encephalitis reported to have been bitten by ticks. Conclusions and Clinical Importance Acute TBEV infection should be a differential diagnosis in horses with signs of neurologic disease and originating from TBEV endemic areas. The establishment of harmonized diagnostic criteria would help to overcome the diagnostic challenges associated with TBEV and other Flavivirus infections in horses