Shamonda virus is spreading in Bavaria – symptoms, transmission and risks

Fever or diarrhea in cattle, sheep and goats can be a sign of Shamonda virus (SHAV) infection. Affected cows sometimes produce significantly less milk. A newly introduced European variant of the virus has been spreading in the Free State for several weeks, as the State Office of Public Health (LGL) and the Bavarian Farmers' Association (BBV) have announced. What is known about the virus? An overview.

How is the virus transmitted?

According to the Friedrich Loeffler Institute (FLI), the newly introduced European Shamonda virus is transmitted by mosquitoes (biting midges) and has appeared mainly in southern Germany, Switzerland and France since July. The State Office of Public Health said animals are mainly infected seasonally, depending on the time the mosquitoes fly. Direct animal-to-animal transmission has not been proven, with the exception of transmission from mother to offspring.

SHAV is related to the notifiable Schmallenberg virus, which also causes loss of milk, fever and diarrhea as symptoms and has been detected in cattle, sheep and goats in Germany for around 15 years.

Which animals are affected?

So far, dairy farms (cattle) have mainly been affected in Bavaria. As the Friedrich Loeffler Institute (FLI) announced just a few days ago, in addition to further evidence in cattle from Baden-Württemberg, Hesse, Saxony and Saarland, there are now positive tests in a horse from Rhineland-Palatinate and an alpaca from Hesse. The Shamonda virus was also found in samples from sheep and goats from Baden-Württemberg.

Can the virus be transmitted to humans?

According to the Friedrich Loeffler Institute, based on current knowledge, there is no relevant risk of infection for humans.

What are the consequences of an infection?

The BBV said that fever, diarrhea and a decrease in milk were detected as symptoms in dairy cows. “The animals recover after a few days.” Nevertheless, this virus, the consequences of which are not yet fully known, is causing great concern for farmers, said a spokeswoman. There is also the possibility that an infection in pregnant animals could lead to abortions or deformities in the calf. According to LGL, these fetal injuries (arthrogryposis-hydranencephaly syndrome) are very likely due to the close relationship of SHAV with the Schmallenberg virus.

Unlike affected cattle, the horse infected in Rhineland-Palatinate showed neurological deficits before its death, according to the FLI.

According to the farmers' association, agricultural businesses would also have to record losses in income due to the decline in milk. The spokeswoman said there is no health risk to consumers from milk and meat from affected animals.

What treatment options are there?

Vaccines against SHAV are not available. The only way to protect animals is to reduce the risk of infection, according to the State Office of Public Health. If acute symptoms such as reduced milk supply, fever and diarrhea occur in animals, a veterinarian should take samples and forward them to the LGL. The LGL advises that abortions, stillbirths and deformed calves or lambs should also be examined for the virus.

Where is the virus spreading in Bavaria?

According to information, evidence of the Shamonda virus is now available from all administrative districts in Bavaria. The number of cases in southern Bavaria is currently higher than in the north of the Free State, said an LGL spokesman. Based on the feedback from practice, the BBV assumes that a large number of cattle farms are affected. The farmers' association considers the current SHAV situation in Germany to be very dynamic and the spread of the virus to be difficult to control.

How much evidence is there and over what period of time?

Since the beginning of August, the State Office of Public Health has detected the virus genome in more than 1,000 samples in the Free State as part of a monitoring program. The pathogen is detected in symptomatic animals via blood samples and after abortions or stillbirths via organ material, especially from the brain and spleen.

How does the monitoring work?

Shamonda virus infections are not reportable. In order to detect the spread of SHAV in the Free State at an early stage, passive monitoring was established, the LGL spokesman said. This means that animals that are already showing symptoms of the disease are specifically tested. The examinations are carried out at the LGL. In active monitoring, on the other hand, samples are taken from an inconspicuous animal population and examined for the presence of a possible disease.