Schmallenberg orthobunyavirus

Virus de Schmallenger

Schmallenberg Orthobunyavirus (SBV) is a virus that belongs to the Orthobunyavirus genus within the Bunyaviridae family. It was first identified in 2011 in the town of Schmallenberg, located in North Rhine-Westphalia, Germany, after which it is named. The virus primarily affects ruminants, including cattle, sheep, and goats, leading to congenital malformations, stillbirths, and febrile illness.

Discovery

The discovery of Schmallenberg Orthobunyavirus was a result of investigations into unexplained milk production drops, fever, and diarrhea in adult cattle, and a surge in the number of congenital malformations in newborn calves, lambs, and goat kids. Advanced molecular techniques led to the identification of this previously unknown virus.

Transmission

Schmallenberg Orthobunyavirus is transmitted by biting midges (Culicoides spp.), which act as vectors for the virus. The disease is not considered zoonotic, meaning there is no evidence that it can be transmitted from animals to humans.

Clinical Signs and Diagnosis

In adult ruminants, the infection may lead to transient symptoms such as fever, reduced milk production, and diarrhea. However, the most significant impact of the virus is observed in pregnant animals, where it can cross the placental barrier and infect the fetus. This can result in congenital malformations, including arthrogryposis (curved joints), hydranencephaly (absence of brain hemispheres), and stillbirths.

Diagnosis of Schmallenberg Orthobunyavirus is primarily based on the detection of the virus or its antibodies in blood or tissue samples. Molecular techniques such as PCR (Polymerase Chain Reaction) are commonly used for virus detection.

Prevention and Control

As of now, there is no specific treatment for Schmallenberg Orthobunyavirus. Control measures primarily focus on preventing exposure to the vector through the use of insect repellents and managing breeding schedules to avoid pregnancies during peak vector activity periods. Vaccines are also available and have been used in some regions to protect against the virus.

Impact

Since its discovery, Schmallenberg Orthobunyavirus has spread to several European countries, causing significant economic losses in affected farms due to decreased productivity, veterinary costs, and the loss of affected offspring. The emergence of the virus has highlighted the need for continuous surveillance and research on vector-borne diseases in livestock.

Research

Ongoing research on Schmallenberg Orthobunyavirus aims to better understand the virus's epidemiology, transmission dynamics, and potential risks to animal health. Studies are also focused on developing more effective vaccines and control strategies to mitigate the impact of the virus on the livestock industry.