Shamonda virus
Profile
In early August 2026, the German Friedrich-Loeffler Institute (FLI) and the Institute of Virology and Immunology (IVI) in Switzerland simultaneously reported the detection of a novel orthobunyavirus in cattle from several herds in southern Germany and Switzerland. Similar cases of the disease, with evidence of the virus, were also reported in France. The novel virus was initially designated the ‘Shamonda-like’ virus. Shortly afterwards, the emergence of a further variant of this virus was reported in north-western Germany. In the order of their discovery, the two virus variants (also referred to elsewhere as ‘clades’) were then named Shamonda virus Europe 1 and Europe 2 (SHAV-EU1 and SHAV-EU2 respectively). According to reports, both SHAV variants are thought to exhibit similar clinical symptoms, but occur in different geographical regions (SHAV-EU1 tends to occur in Central Europe, whilst SHAV-EU2 tends to occur in Northern Europe). Differences in the range of animal species susceptible to SHAV-EU1 and SHAV-EU2, if any, have not yet been sufficiently researched; consequently, the term ‘SHAV’ (encompassing both variants) is primarily used here.
Diagnostic procedures were rapidly established at AGES, and so in mid-August 2026, SHAV was detected simultaneously on two Austrian cattle farms in the federal states of Vorarlberg and Upper Austria. Infections have since been detected throughout the country.
SHAV, like the Schmallenberg virus (SBV) – which has been present in this country since 2012 – and the bluetongue virus, is transmitted by midges; the infection can lead to febrile systemic illness with loss of appetite, diarrhoea and reduced milk yield, as well as to abortions and deformities in newborn calves, lambs and kids. Genetic material of SHAV has now been detected in several countries in the brains of horses that had died from neurological symptoms. The virus has also been detected in an alpaca. A single case of SHAV detection in a human has been reported from France. This involved a severely immunocompromised individual who died following encephalitis. No general risk to humans can be inferred from this isolated case; further investigations are required to determine this.
Occurrence
Infections with SHAV have been known in Africa for many decades, and cases have also been detected in Japan. Since the summer of 2026, cases have been detected in Belgium, Germany, France, Italy, the Netherlands, Austria, Portugal, Switzerland and Spain. Further spread across Europe is to be expected.
Symptoms
In cattle, particularly dairy cattle, the main symptoms reported to date have been watery diarrhoea, fever and a decline in milk yield. In most cases, several animals are affected at the same time. Cases reported in Austria mainly involve cattle; it is possible that the symptoms in sheep and goats are less pronounced or even subclinical. Infection during a specific stage of pregnancy can, in the case of many orthobunyaviruses – and presumably also SHAV – lead to delayed foetal malformations or weak newborns.
The affected horses, in which SHAV genetic material was found in the brain, had exhibited neurological symptoms; SHAV could therefore be considered in the differential diagnosis of other viral encephalitis in horses (e.g. West Nile virus, herpesvirus, bornavirus). It should be noted that detection of the virus in living horses has so far been documented only rarely.
Therapy
There is no curative treatment. Affected animals can be treated with antipyretic and anti-inflammatory medication to provide symptomatic relief. Please refer to the relevant package leaflets for details of any side effects or contraindications. In the case of the related SBV, the majority of infections do not lead to clinical disease, meaning that the spread is only subsequently detected through antibody tests.
The situation in Austria
The first case of SHAV was detected in Austria in mid-August 2026. Since then, the infection has spread throughout the country. In Austria, cases have been largely confined to cattle; to date, the virus has also been detected in one sheep and in the brains of two horses from Lower Austria. The disease is not notifiable. There are no official tests for the virus, and a positive diagnosis does not trigger any official control measures.
Specialized information
SHAV is an enveloped RNA virus with a single-stranded, segmented genome belonging to the family Bunyaviridae, genus Orthobunyavirus. Related viruses (SBV, Shamonda, Aino and Akabane viruses; the ‘Simbu serogroup’) are found in Australia, Asia, Africa and, since 2011, also in Europe, where they generally cause only very mild clinical symptoms initially. However, if pregnant animals become infected, significant congenital defects, premature births and fertility problems may occur at a later stage.
Based on current knowledge, these viruses are not considered to pose a risk to humans.
As the disease or infection is not notifiable, detection has no consequences under animal health legislation.
Transmission
As with SBV and Shamondavirus, transmission is thought to occur via midges (Culicoides spp.). It is likely that susceptible dams can transmit the infection to the foetuses via the placenta, which may result in disturbances in the foetuses’ neurological development.
Symptoms
In acute infection: In most cases, viruses of the Simbu serogroup cause no clinical symptoms, or only mild and short-lived ones, characterised by fever, diarrhoea and/or a decline in milk yield. Acute infection may also presumably lead to abortions in pregnant animals. In horses in which SHAV was found in the brain post-mortem, neurological symptoms such as lethargy, coordination and movement disorders, muscle twitching, nystagmus or squinting were observed. Neurological disorders may also occur in alpacas, although the evidence on this is currently still inconclusive.
In the case of transplacental infection: if pregnant, previously uninfected dams are infected during a susceptible period (in sheep, presumably between the 30th and 50th day; in cattle, approximately between the 75th and 175th days of gestation), infection with viruses of the Simbu serogroup (e.g. SBV) can lead to severe malformations of the limbs (arthrogryposis) and head (hydrocephalus, torticollis, hydranencephaly). Depending on the time of infection and the gestation period of the various affected species, young animals with malformations and/or poor vitality are born in winter and spring. Whether these symptoms also occur with SHAV remains to be clarified.
Diagnostics
In acute cases, suitable samples for testing include EDTA-anticoagulated blood and/or serum, as well as faeces containing diarrhoea and aborted foetal material. If cerebrospinal fluid has been collected from horses with neurological disorders, the cerebrospinal fluid may also be tested for SHAV. To investigate horses that have died or been euthanised with neurological symptoms, brain tissue is required; ideally, the entire head should be submitted. The brain should also be examined in the case of lambs and calves that have died or been euthanised with malformations or noticeable weakness; in such cases, the entire animal may be sent in. In the case of ruminants that have died or been euthanised, the spleen may also be examined for detection of the virus.
Testing for SHAV must be paid for privately.
Testing for antibodies in blood (serum) can determine whether the animal has been exposed to the virus. At present, there are no commercially available ELISA tests capable of specifically detecting antibodies directed against SHAV; as cross-reactions with SBV antibodies occur. It is thought that SBV and SHAV can be distinguished using a virus neutralisation test; relevant investigations into this are still ongoing.
PCR testing directly detects the virus or viral components. The duration for which SHAV can be detected in blood or tissues has not yet been clarified; it is thought that, like SBV, it is detectable in blood for only a few days. Whether SHAV can also be excreted in semen has not yet been investigated either.
In all cases, samples should ideally be dispatched to the laboratory by an authorised logistics company, with the inclusion of coolants and in accordance with the relevant transport regulations (UN3373).
Contact
Institut für veterinärmedizinische Untersuchungen Mödling
- vetmed.moedling@ages.at
- +43 50 555 38112
-
Robert Koch-Gasse 17
2340 Mödling
Last updated: 27.10.2026
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