Preliminary estimate of Schmallenberg virus infection impact in sheep flocks – France

Abstract

Schmallenberg virus (SbV) infection is an emerging livestock disease caused by a novel Orthobunyavirus which was first identified in germany in november 2011. non-specific clinical signs such as fever, decreased milk production and diarrhoea are associated with the acute infection in cattle, while late abortions and birth defects in newborns can be associated with the infection of pregnant cows, ewes and goats (hoffmann and others 2012, Van den brom and others 2012). as of march 30, 2012, since the first identification of congenital forms of SbV virus infection in The netherlands in December 2011, about 3000 confirmed outbreaks have been reported in eight european countries (belgium, France, germany, Italy, luxembourg, The netherlands, Spain, UK) (French national Surveillance Platform for animal health 2012). however, little is known about SbV virus infection, especially with regard to its clinical impact in the affected herds. SbV emergence is closely monitored in France. Farmers are urged to contact their veterinarian when encountering cases of ruminant neonates or fetuses stillborn, malformed or showing nervous disorders. a brain sample is collected on any newborn suspected of congenital SbV until a first confirmation of the infection is obtained for the herd. an SbV diagnostic test is performed in state diagnostic laboratories, using real-time quantitative reverse transcription Pcr (rT-qPcr). The first cases of SbV virus infection were confirmed in France in deformed lambs on January 25, 2012. as of march 30, 2012, 1048 SbV-positive herds have been identified, 958 sheep, 76 cattle and 14 goat herds. In the framework of the French national Surveillance Platform for animal health, a survey has been launched in cattle, sheep and goat

Impact of Schmallenberg virus on British sheep farms during the 2011/2012 lambing season

“…Malformations in fetuses and lambs associated with SBV infection include arthrogryposis, skeletal muscle dysplasia, deformities of the cervical and thoracic vertebral column, overshot jaw, and nervous signs (van den Brom and others 2012). Ewes can give birth to normal and deformed lambs from the same pregnancy (Dominguez and others 2012, Lievaart-Peterson and others 2012, Doceul and others 2013). SBV-affected lambs have been delivered at term, with some stillborn and a few severely deformed but still alive.…”

Was the French clinical surveillance system of bovine brucellosis influenced by the occurrence and surveillance of other abortive diseases?

“…Non-specific clinical signs such as fever, decreased milk production and diarrhoea are associated with the acute infection in cattle, while late abortions and birth defects in newborns were reported on pregnant females infected by SBV (Hoffmann et al, 2012). Since its emergence, SBV infection has been closely monitored (Dominguez et al, 2012b). Farmers were urged to contact their veterinarian when encountering cases of ruminant neonates or foetuses stillborn, malformed or showing nervous disorders to test them for SBV (Dominguez et al, 2012b;Gache et al, 2013a).…”

“…Since its emergence, SBV infection has been closely monitored (Dominguez et al, 2012b). Farmers were urged to contact their veterinarian when encountering cases of ruminant neonates or foetuses stillborn, malformed or showing nervous disorders to test them for SBV (Dominguez et al, 2012b;Gache et al, 2013a). During season I of SBV (from September 1, 2011 to August 31, 2012), congenital forms of SBV infection were detected in 2018 cattle herds, located in 74 départements (a département is a French administrative unit with a mean area of 5800 km 2 ).…”

Schmallenberg disease in sheep or goats: Past, present and future

“…Depending on the stage of pregnancy at the probable time of infection, clinical impact of Schmallenberg disease varied between flocks (Dominguez et al, 2012). Clinical impact measured in females can include decreased milk production, non-pregnancy, repeat breeding, abortion and fetal dystocia caused by malformed arthrogrypotic lambs, possibly resulting in death during parturition.…”