Summary of taxonomy changes ratified by the International Committee on Taxonomy of Viruses (ICTV) from the Animal dsRNA and ssRNA(-) Viruses Subcommittee, 2025.

RNA viruses are ubiquitous in the environment and are important pathogens of humans, animals and plants. In 2024, the International Committee on Taxonomy of Viruses Animal dsRNA and ssRNA(-) Viruses Subcommittee submitted 18 taxonomic proposals for consideration. These proposals expanded the known virosphere by classifying 9 new genera and 88 species for newly detected virus genomes.

Annual (2024) taxonomic update of RNA-directed RNA polymerase-encoding negative-sense RNA viruses (realm : kingdom : phylum ).

In April 2024, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum was expanded by 1 new order, 1 new family, 6 new subfamilies, 34 new genera and 270 new species. One class, two orders and six species were renamed. Seven families and 12 genera were moved; ten species were renamed and moved; and nine species were abolished.

Pathological findings in raccoon dogs (Nyctereutes procyonoides) in Schleswig-Holstein, Germany.

Raccoon dogs (Nyctereutes procyonoides) originated from East Asia and are listed as invasive alien species of Union concern in the European Union. Apart from their potential negative impact on native fauna as predators and competitors, they are discussed as reservoirs and vectors for various infectious diseases. Between 2021 and 2022, comprehensive post-mortem examinations of 110 raccoon dogs were performed as part of a health and risk assessment study of selected invasive alien species in Schleswig-Holstein, Germany.

Retrospective analysis of clustered neuroinflammatory and neurodegenerative diseases in captive lions in the early 1970s.

Rustrela virus (RusV), a recently discovered pathogen for domestic and wildlife animals, was identified as the causative agent of meningoencephalomyelitis in domestic cats and various zoo animals including lions. To analyze a past outbreak of increased mortality in lions and to reveal its possible etiological relationship with an RusV infection, this retrospective study re-evaluates 20 cases of lions originating from a zoo in Western Germany using archived formalin-fixed paraffin-embedded (FFPE) tissues. Animals with different neurologic signs were submitted for necropsy between December 1970 and April 1971.

Borna disease virus 2 maintains genomic polymorphisms by superinfection in persistently infected cells.

Mammalian orthobornaviruses, such as Borna disease virus 1 (BoDV-1) and variegated squirrel bornavirus 1, are zoonotic pathogens that cause fatal encephalitis in humans. BoDV-2, another mammalian orthobornavirus with high genetic homology to BoDV-1, is believed to share the same geographical distribution as BoDV-1, indicating its potential risk to human health. However, due to the limited number of isolations, the virological characteristics of BoDV-2, such as pathogenicity and infectivity, remain largely unexplored.

Evidence of rustrela virus-associated feline staggering disease in Sweden since the 1970s.

Background: Staggering disease (SD) is a severe neurological disease that has been regularly reported in Swedish cats since the beginning of the 1970s. The aetiology of SD has been debated, but novel rustrela virus (RusV) was recently suggested as the causative agent in Swedish cases dating from 2017 onwards. However, whether RusV was associated with earlier cases of feline SD in Sweden remained unknown.

Lethal Borna disease virus 1 infections of humans and animals - in-depth molecular epidemiology and phylogeography.

Borna disease virus 1 (BoDV-1) is the causative agent of Borna disease, a fatal neurologic disorder of domestic mammals and humans, resulting from spill-over infection from its natural reservoir host, the bicolored white-toothed shrew (Crocidura leucodon). The known BoDV-1-endemic area is remarkably restricted to parts of Germany, Austria, Switzerland and Liechtenstein. To gain comprehensive data on its occurrence, we analysed diagnostic material from suspected BoDV-1-induced encephalitis cases based on clinical and/or histopathological diagnosis.

Rustrela Virus in Wild Mountain Lion (Puma concolor) with Staggering Disease, Colorado, USA.

We identified a rustrela virus variant in a wild mountain lion (Puma concolor) in Colorado, USA. The animal had clinical signs and histologic lesions compatible with staggering disease. Considering its wide host range in Europe, rustrela virus should be considered as a cause for neurologic diseases among mammal species in North America.

The first confirmed cases of pigeon rotavirus A (RVA) infection in domestic pigeons in Poland.

Introduction: Although the presence of rotaviruses in pigeon samples has been reported since the 1980s, its importance as an aetiological agent of the "classical" young pigeon disease (YPD) was not proven until 2020, when the Henle-Koch postulates were confirmed for pigeon-type rotavirus A (RVA) genotype G18P(17).

Material And Methods: From 2011 to 2020, archived liver samples from 117 pigeons submitted by 74 individual lofts were tested for the presence of pigeon-type RVA using a VP6-specific RT-qPCR test. For four positive racing pigeons, a more detailed necropsy and histopathological analysis was performed.

One Health in action: Investigation of the first detected local cluster of fatal borna disease virus 1 (BoDV-1) encephalitis, Germany 2022.

Background: Zoonotic Borna disease virus 1 (BoDV-1) causes fatal encephalitis in humans and animals. Subsequent to the detection of two paediatric cases in a Bavarian municipality in Germany within three years, we conducted an interdisciplinary One Health investigation. We aimed to explore seroprevalence in a local human population with a risk for BoDV-1 exposure as well as viral presence in environmental samples from local sites and BoDV-1 prevalence within the local small mammal population and its natural reservoir, the bicoloured white-toothed shrew (Crocidura leucodon).

Feline morbillivirus infection associated with fatal encephalitis in a Bengal cat.

Feline morbillivirus (FeMV) is a recently discovered morbillivirus of the family Paramyxoviridae, which include several highly contagious viruses with zoonotic potential. In this case report we describe the detection of FeMV in archived brain tissue of a 2-month-old Bengal cat with nonsuppurative encephalitis from the year 2011 in Switzerland by high-throughput sequencing (HTS). Our metagenomics approach was able to obtain a full-length sequence covering the entire FeMV genome.

Continuous presence of genetically diverse rustrela virus lineages in yellow-necked field mouse reservoir populations in northeastern Germany.

Rustrela virus (RusV; species , family ) was discovered in different zoo animal species affected by fatal encephalitis. Simultaneous RusV RNA detection in multiple yellow-necked field mice () suggested this rodent as a reservoir of RusV. Here, we investigated 1,264 yellow-necked field mice and sympatric other small mammals from different regions in Germany for RusV RNA using an optimized reverse transcription-quantitative polymerase chain reaction (RT-qPCR) protocol and high-throughput sequencing.

Reverse genetics of parrot bornavirus 4 reveals a unique splicing of the glycoprotein gene that affects viral propagation.

Viruses can utilize host splicing machinery to enable the expression of multiple genes from a limited-sized genome. Orthobornaviruses use alternative splicing to regulate the expression level of viral proteins and achieve efficient viral replication in the nucleus. Although more than 20 orthobornaviruses have been identified belonging to eight different viral species, virus-specific splicing has not been demonstrated.

Borna disease virus 1 infection in alpacas: Comparison of pathological lesions and viral distribution to other dead-end hosts.

Borna disease is a progressive meningoencephalitis caused by spillover of the Borna disease virus 1 (BoDV-1) to horses and sheep and has gained attention due to its zoonotic potential. New World camelids are also highly susceptible to the disease; however, a comprehensive description of the pathological lesions and viral distribution is lacking for these hosts. Here, the authors describe the distribution and severity of inflammatory lesions in alpacas ( = 6) naturally affected by this disease in comparison to horses ( = 8) as known spillover hosts.

[Viral zoonoses in Germany: a One Health perspective].

The COVID-19 pandemic and the increasing occurrence of monkeypox (mpox) diseases outside Africa have illustrated the vulnerability of populations to zoonotic pathogens. In addition, other viral zoonotic pathogens have gained importance in recent years.This review article addresses six notifiable viral zoonotic pathogens as examples to highlight the need for the One Health approach in order to understand the epidemiology of the diseases and to derive recommendations for action by the public health service.

Cerebrospinal fluid in Borna disease virus 1 (BoDV-1) encephalitis.

Borna disease virus 1 (BoDV-1) has been recognized as a rare cause of very severe encephalitis with rapid onset in central Europe. Data on cerebrospinal fluid (CSF) analysis have not yet been analyzed in detail. Here, we present the first study on CSF changes in BoDV-1 encephalitis.

Connect to Protect: Dynamics and Genetic Connections of Highly Pathogenic Avian Influenza Outbreaks in Poultry from 2016 to 2021 in Germany.

During autumn/winter in 2016-2017 and 2020-2021, highly pathogenic avian influenza viruses (HPAIV) caused severe outbreaks in Germany and Europe. Multiple clade 2.3.

Rustrela virus infection - An emerging neuropathogen of red-necked wallabies (Macropus rufogriseus).

The rustrela virus (RusV) was recently described as a novel pathogen in a circumscribed area of northern Germany close to the Baltic Sea. Up to now, the virus has been detected in cases of fatal non-suppurative meningoencephalitis in zoo animals of different species and a single wild carnivore as well as in apparently healthy yellow-necked field mice (Apodemus flavicollis). Data regarding the background of this previously undiscovered pathogen, including clinical presentation of the disease, host range and distribution of the virus, are still limited.