May 13, 2020
New study examines re-emergence of bluetongue virus in Europe
A new study led by researchers from the University of Glasgow in the UK sheds light on why the bluetongue virus (BTV), a pathogen that infects sheep and cattle, has re-emerged in Europe after an absence of five years.
BTV was first detected in Europe in 2006, according to the study that was published in the science journal PLOS Biology, Science Daily reported. It was controlled through mass vaccination by 2010, and no cases were reported until it re-emerged in France in 2015.
The researchers compared genomes of the BTV before and after it re-emerged in France in 2015. The genome analyses showed that during both the 2006 and 2015 outbreaks, BTV accumulated novel mutations. However, during the period in between the two outbreaks, the researchers noted a lack of mutations, which means that the virus did not likely circulate during this period.
The re-emergence of the virus in France, the study said, could have been caused by human activities, based on the virus' unusual genetic makeup.
According to the study, the genetic similarity between the original and re-emergent viruses suggests that the 2015 outbreak was caused by infectious material that somehow arose from the first outbreak.
The researchers added that under a more plausible scenario, the virus may have resurfaced after being stored in frozen samples.
Prof. Massimo Palmarini, one of the senior researchers, said, however, that the most plausible explanation is that "exposure to infectious material, stored from the earlier outbreak", caused the re-emergence of the virus in Europe.